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Fix build of 4.14 kernel in dunfell OE #4

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merged 1 commit into from
Aug 19, 2020

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dunfell OE sets a gcc parameter for CFLAGS which is inherited by this Makefile. If host's gcc is old and doesn't support the parameter, build fails.

Cherry-picked this commit from upstream 4.14 linux-stable-rt that fixes it.

commit f73b3cc upstream.

If the build user has the CFLAGS variable set in their environment,
objtool blindly appends to it, which can cause unexpected behavior.

Clobber CFLAGS to ensure consistent objtool compilation behavior.

Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/83a276df209962e6058fcb6c615eef9d401c21bc.1567121311.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CC: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ni/rtos

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@gratian gratian left a comment

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Ship it!

@gratian gratian merged commit 27f65d4 into ni:nilrt/master/4.14 Aug 19, 2020
gratian referenced this pull request in gratian/linux Nov 4, 2020
Dave reported a problem with my rwsem conversion patch where we got the
following lockdep splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.9.0-default+ #1297 Not tainted
  ------------------------------------------------------
  kswapd0/76 is trying to acquire lock:
  ffff9d5d25df2530 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]

  but task is already holding lock:
  ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #4 (fs_reclaim){+.+.}-{0:0}:
	 __lock_acquire+0x582/0xac0
	 lock_acquire+0xca/0x430
	 fs_reclaim_acquire.part.0+0x25/0x30
	 kmem_cache_alloc+0x30/0x9c0
	 alloc_inode+0x81/0x90
	 iget_locked+0xcd/0x1a0
	 kernfs_get_inode+0x1b/0x130
	 kernfs_get_tree+0x136/0x210
	 sysfs_get_tree+0x1a/0x50
	 vfs_get_tree+0x1d/0xb0
	 path_mount+0x70f/0xa80
	 do_mount+0x75/0x90
	 __x64_sys_mount+0x8e/0xd0
	 do_syscall_64+0x2d/0x70
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #3 (kernfs_mutex){+.+.}-{3:3}:
	 __lock_acquire+0x582/0xac0
	 lock_acquire+0xca/0x430
	 __mutex_lock+0xa0/0xaf0
	 kernfs_add_one+0x23/0x150
	 kernfs_create_dir_ns+0x58/0x80
	 sysfs_create_dir_ns+0x70/0xd0
	 kobject_add_internal+0xbb/0x2d0
	 kobject_add+0x7a/0xd0
	 btrfs_sysfs_add_block_group_type+0x141/0x1d0 [btrfs]
	 btrfs_read_block_groups+0x1f1/0x8c0 [btrfs]
	 open_ctree+0x981/0x1108 [btrfs]
	 btrfs_mount_root.cold+0xe/0xb0 [btrfs]
	 legacy_get_tree+0x2d/0x60
	 vfs_get_tree+0x1d/0xb0
	 fc_mount+0xe/0x40
	 vfs_kern_mount.part.0+0x71/0x90
	 btrfs_mount+0x13b/0x3e0 [btrfs]
	 legacy_get_tree+0x2d/0x60
	 vfs_get_tree+0x1d/0xb0
	 path_mount+0x70f/0xa80
	 do_mount+0x75/0x90
	 __x64_sys_mount+0x8e/0xd0
	 do_syscall_64+0x2d/0x70
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (btrfs-extent-00){++++}-{3:3}:
	 __lock_acquire+0x582/0xac0
	 lock_acquire+0xca/0x430
	 down_read_nested+0x45/0x220
	 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
	 __btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
	 btrfs_search_slot+0x6d4/0xfd0 [btrfs]
	 check_committed_ref+0x69/0x200 [btrfs]
	 btrfs_cross_ref_exist+0x65/0xb0 [btrfs]
	 run_delalloc_nocow+0x446/0x9b0 [btrfs]
	 btrfs_run_delalloc_range+0x61/0x6a0 [btrfs]
	 writepage_delalloc+0xae/0x160 [btrfs]
	 __extent_writepage+0x262/0x420 [btrfs]
	 extent_write_cache_pages+0x2b6/0x510 [btrfs]
	 extent_writepages+0x43/0x90 [btrfs]
	 do_writepages+0x40/0xe0
	 __writeback_single_inode+0x62/0x610
	 writeback_sb_inodes+0x20f/0x500
	 wb_writeback+0xef/0x4a0
	 wb_do_writeback+0x49/0x2e0
	 wb_workfn+0x81/0x340
	 process_one_work+0x233/0x5d0
	 worker_thread+0x50/0x3b0
	 kthread+0x137/0x150
	 ret_from_fork+0x1f/0x30

  -> #1 (btrfs-fs-00){++++}-{3:3}:
	 __lock_acquire+0x582/0xac0
	 lock_acquire+0xca/0x430
	 down_read_nested+0x45/0x220
	 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
	 __btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
	 btrfs_search_slot+0x6d4/0xfd0 [btrfs]
	 btrfs_lookup_inode+0x3a/0xc0 [btrfs]
	 __btrfs_update_delayed_inode+0x93/0x2c0 [btrfs]
	 __btrfs_commit_inode_delayed_items+0x7de/0x850 [btrfs]
	 __btrfs_run_delayed_items+0x8e/0x140 [btrfs]
	 btrfs_commit_transaction+0x367/0xbc0 [btrfs]
	 btrfs_mksubvol+0x2db/0x470 [btrfs]
	 btrfs_mksnapshot+0x7b/0xb0 [btrfs]
	 __btrfs_ioctl_snap_create+0x16f/0x1a0 [btrfs]
	 btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs]
	 btrfs_ioctl+0xd0b/0x2690 [btrfs]
	 __x64_sys_ioctl+0x6f/0xa0
	 do_syscall_64+0x2d/0x70
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
	 check_prev_add+0x91/0xc60
	 validate_chain+0xa6e/0x2a20
	 __lock_acquire+0x582/0xac0
	 lock_acquire+0xca/0x430
	 __mutex_lock+0xa0/0xaf0
	 __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
	 btrfs_evict_inode+0x3cc/0x560 [btrfs]
	 evict+0xd6/0x1c0
	 dispose_list+0x48/0x70
	 prune_icache_sb+0x54/0x80
	 super_cache_scan+0x121/0x1a0
	 do_shrink_slab+0x16d/0x3b0
	 shrink_slab+0xb1/0x2e0
	 shrink_node+0x230/0x6a0
	 balance_pgdat+0x325/0x750
	 kswapd+0x206/0x4d0
	 kthread+0x137/0x150
	 ret_from_fork+0x1f/0x30

  other info that might help us debug this:

  Chain exists of:
    &delayed_node->mutex --> kernfs_mutex --> fs_reclaim

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(fs_reclaim);
				 lock(kernfs_mutex);
				 lock(fs_reclaim);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by kswapd0/76:
   #0: ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
   #1: ffffffffa40b8b58 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x54/0x2e0
   #2: ffff9d5d322390e8 (&type->s_umount_key#26){++++}-{3:3}, at: trylock_super+0x16/0x50

  stack backtrace:
  CPU: 2 PID: 76 Comm: kswapd0 Not tainted 5.9.0-default+ #1297
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   dump_stack+0x77/0x97
   check_noncircular+0xff/0x110
   ? save_trace+0x50/0x470
   check_prev_add+0x91/0xc60
   validate_chain+0xa6e/0x2a20
   ? save_trace+0x50/0x470
   __lock_acquire+0x582/0xac0
   lock_acquire+0xca/0x430
   ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
   __mutex_lock+0xa0/0xaf0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
   ? __lock_acquire+0x582/0xac0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
   ? btrfs_evict_inode+0x30b/0x560 [btrfs]
   ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
   __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs]
   btrfs_evict_inode+0x3cc/0x560 [btrfs]
   evict+0xd6/0x1c0
   dispose_list+0x48/0x70
   prune_icache_sb+0x54/0x80
   super_cache_scan+0x121/0x1a0
   do_shrink_slab+0x16d/0x3b0
   shrink_slab+0xb1/0x2e0
   shrink_node+0x230/0x6a0
   balance_pgdat+0x325/0x750
   kswapd+0x206/0x4d0
   ? finish_wait+0x90/0x90
   ? balance_pgdat+0x750/0x750
   kthread+0x137/0x150
   ? kthread_mod_delayed_work+0xc0/0xc0
   ret_from_fork+0x1f/0x30

This happens because we are still holding the path open when we start
adding the sysfs files for the block groups, which creates a dependency
on fs_reclaim via the tree lock.  Fix this by dropping the path before
we start doing anything with sysfs.

Reported-by: David Sterba <dsterba@suse.com>
CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
gratian referenced this pull request in gratian/linux Nov 4, 2020
Very sporadically I had test case btrfs/069 from fstests hanging (for
years, it is not a recent regression), with the following traces in
dmesg/syslog:

  [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started
  [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0
  [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished
  [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds.
  [162513.514318]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.514747] task:btrfs-transacti state:D stack:    0 pid:1356167 ppid:     2 flags:0x00004000
  [162513.514751] Call Trace:
  [162513.514761]  __schedule+0x5ce/0xd00
  [162513.514765]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.514771]  schedule+0x46/0xf0
  [162513.514844]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.514850]  ? finish_wait+0x90/0x90
  [162513.514864]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.514879]  transaction_kthread+0xa4/0x170 [btrfs]
  [162513.514891]  ? btrfs_cleanup_transaction+0x660/0x660 [btrfs]
  [162513.514894]  kthread+0x153/0x170
  [162513.514897]  ? kthread_stop+0x2c0/0x2c0
  [162513.514902]  ret_from_fork+0x22/0x30
  [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds.
  [162513.515192]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.515680] task:fsstress        state:D stack:    0 pid:1356184 ppid:1356177 flags:0x00004000
  [162513.515682] Call Trace:
  [162513.515688]  __schedule+0x5ce/0xd00
  [162513.515691]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.515697]  schedule+0x46/0xf0
  [162513.515712]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.515716]  ? finish_wait+0x90/0x90
  [162513.515729]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.515743]  btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs]
  [162513.515753]  btrfs_sync_fs+0x61/0x1c0 [btrfs]
  [162513.515758]  ? __ia32_sys_fdatasync+0x20/0x20
  [162513.515761]  iterate_supers+0x87/0xf0
  [162513.515765]  ksys_sync+0x60/0xb0
  [162513.515768]  __do_sys_sync+0xa/0x10
  [162513.515771]  do_syscall_64+0x33/0x80
  [162513.515774]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.515781] RIP: 0033:0x7f5238f50bd7
  [162513.515782] Code: Bad RIP value.
  [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2
  [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7
  [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a
  [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0
  [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a
  [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340
  [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds.
  [162513.516064]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.516617] task:fsstress        state:D stack:    0 pid:1356185 ppid:1356177 flags:0x00000000
  [162513.516620] Call Trace:
  [162513.516625]  __schedule+0x5ce/0xd00
  [162513.516628]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.516634]  schedule+0x46/0xf0
  [162513.516647]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.516650]  ? finish_wait+0x90/0x90
  [162513.516662]  start_transaction+0x4d7/0x5f0 [btrfs]
  [162513.516679]  btrfs_setxattr_trans+0x3c/0x100 [btrfs]
  [162513.516686]  __vfs_setxattr+0x66/0x80
  [162513.516691]  __vfs_setxattr_noperm+0x70/0x200
  [162513.516697]  vfs_setxattr+0x6b/0x120
  [162513.516703]  setxattr+0x125/0x240
  [162513.516709]  ? lock_acquire+0xb1/0x480
  [162513.516712]  ? mnt_want_write+0x20/0x50
  [162513.516721]  ? rcu_read_lock_any_held+0x8e/0xb0
  [162513.516723]  ? preempt_count_add+0x49/0xa0
  [162513.516725]  ? __sb_start_write+0x19b/0x290
  [162513.516727]  ? preempt_count_add+0x49/0xa0
  [162513.516732]  path_setxattr+0xba/0xd0
  [162513.516739]  __x64_sys_setxattr+0x27/0x30
  [162513.516741]  do_syscall_64+0x33/0x80
  [162513.516743]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.516745] RIP: 0033:0x7f5238f56d5a
  [162513.516746] Code: Bad RIP value.
  [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc
  [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a
  [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470
  [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700
  [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004
  [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0
  [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds.
  [162513.517064]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.517763] task:fsstress        state:D stack:    0 pid:1356196 ppid:1356177 flags:0x00004000
  [162513.517780] Call Trace:
  [162513.517786]  __schedule+0x5ce/0xd00
  [162513.517789]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.517796]  schedule+0x46/0xf0
  [162513.517810]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.517814]  ? finish_wait+0x90/0x90
  [162513.517829]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.517845]  btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs]
  [162513.517857]  btrfs_sync_fs+0x61/0x1c0 [btrfs]
  [162513.517862]  ? __ia32_sys_fdatasync+0x20/0x20
  [162513.517865]  iterate_supers+0x87/0xf0
  [162513.517869]  ksys_sync+0x60/0xb0
  [162513.517872]  __do_sys_sync+0xa/0x10
  [162513.517875]  do_syscall_64+0x33/0x80
  [162513.517878]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.517881] RIP: 0033:0x7f5238f50bd7
  [162513.517883] Code: Bad RIP value.
  [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2
  [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7
  [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053
  [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0
  [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053
  [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340
  [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds.
  [162513.518298]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.519157] task:fsstress        state:D stack:    0 pid:1356197 ppid:1356177 flags:0x00000000
  [162513.519160] Call Trace:
  [162513.519165]  __schedule+0x5ce/0xd00
  [162513.519168]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.519174]  schedule+0x46/0xf0
  [162513.519190]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.519193]  ? finish_wait+0x90/0x90
  [162513.519206]  start_transaction+0x4d7/0x5f0 [btrfs]
  [162513.519222]  btrfs_create+0x57/0x200 [btrfs]
  [162513.519230]  lookup_open+0x522/0x650
  [162513.519246]  path_openat+0x2b8/0xa50
  [162513.519270]  do_filp_open+0x91/0x100
  [162513.519275]  ? find_held_lock+0x32/0x90
  [162513.519280]  ? lock_acquired+0x33b/0x470
  [162513.519285]  ? do_raw_spin_unlock+0x4b/0xc0
  [162513.519287]  ? _raw_spin_unlock+0x29/0x40
  [162513.519295]  do_sys_openat2+0x20d/0x2d0
  [162513.519300]  do_sys_open+0x44/0x80
  [162513.519304]  do_syscall_64+0x33/0x80
  [162513.519307]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.519309] RIP: 0033:0x7f5238f4a903
  [162513.519310] Code: Bad RIP value.
  [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
  [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903
  [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470
  [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002
  [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013
  [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620
  [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds.
  [162513.519727]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.520508] task:btrfs           state:D stack:    0 pid:1356211 ppid:1356178 flags:0x00004002
  [162513.520511] Call Trace:
  [162513.520516]  __schedule+0x5ce/0xd00
  [162513.520519]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.520525]  schedule+0x46/0xf0
  [162513.520544]  btrfs_scrub_pause+0x11f/0x180 [btrfs]
  [162513.520548]  ? finish_wait+0x90/0x90
  [162513.520562]  btrfs_commit_transaction+0x45a/0xc30 [btrfs]
  [162513.520574]  ? start_transaction+0xe0/0x5f0 [btrfs]
  [162513.520596]  btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs]
  [162513.520619]  btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs]
  [162513.520639]  btrfs_ioctl+0x2a25/0x36f0 [btrfs]
  [162513.520643]  ? do_sigaction+0xf3/0x240
  [162513.520645]  ? find_held_lock+0x32/0x90
  [162513.520648]  ? do_sigaction+0xf3/0x240
  [162513.520651]  ? lock_acquired+0x33b/0x470
  [162513.520655]  ? _raw_spin_unlock_irq+0x24/0x50
  [162513.520657]  ? lockdep_hardirqs_on+0x7d/0x100
  [162513.520660]  ? _raw_spin_unlock_irq+0x35/0x50
  [162513.520662]  ? do_sigaction+0xf3/0x240
  [162513.520671]  ? __x64_sys_ioctl+0x83/0xb0
  [162513.520672]  __x64_sys_ioctl+0x83/0xb0
  [162513.520677]  do_syscall_64+0x33/0x80
  [162513.520679]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.520681] RIP: 0033:0x7fc3cd307d87
  [162513.520682] Code: Bad RIP value.
  [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
  [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87
  [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003
  [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
  [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003
  [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001
  [162513.520703]
		  Showing all locks held in the system:
  [162513.520712] 1 lock held by khungtaskd/54:
  [162513.520713]  #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197
  [162513.520728] 1 lock held by in:imklog/596:
  [162513.520729]  #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60
  [162513.520782] 1 lock held by btrfs-transacti/1356167:
  [162513.520784]  #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs]
  [162513.520798] 1 lock held by btrfs/1356190:
  [162513.520800]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60
  [162513.520805] 1 lock held by fsstress/1356184:
  [162513.520806]  #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0
  [162513.520811] 3 locks held by fsstress/1356185:
  [162513.520812]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50
  [162513.520815]  #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120
  [162513.520820]  #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]
  [162513.520833] 1 lock held by fsstress/1356196:
  [162513.520834]  #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0
  [162513.520838] 3 locks held by fsstress/1356197:
  [162513.520839]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50
  [162513.520843]  #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50
  [162513.520846]  #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]
  [162513.520858] 2 locks held by btrfs/1356211:
  [162513.520859]  #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs]
  [162513.520877]  #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]

This was weird because the stack traces show that a transaction commit,
triggered by a device replace operation, is blocking trying to pause any
running scrubs but there are no stack traces of blocked tasks doing a
scrub.

After poking around with drgn, I noticed there was a scrub task that was
constantly running and blocking for shorts periods of time:

  >>> t = find_task(prog, 1356190)
  >>> prog.stack_trace(t)
  #0  __schedule+0x5ce/0xcfc
  #1  schedule+0x46/0xe4
  #2  schedule_timeout+0x1df/0x475
  #3  btrfs_reada_wait+0xda/0x132
  #4  scrub_stripe+0x2a8/0x112f
  #5  scrub_chunk+0xcd/0x134
  ni#6  scrub_enumerate_chunks+0x29e/0x5ee
  ni#7  btrfs_scrub_dev+0x2d5/0x91b
  ni#8  btrfs_ioctl+0x7f5/0x36e7
  ni#9  __x64_sys_ioctl+0x83/0xb0
  ni#10 do_syscall_64+0x33/0x77
  ni#11 entry_SYSCALL_64+0x7c/0x156

Which corresponds to:

int btrfs_reada_wait(void *handle)
{
    struct reada_control *rc = handle;
    struct btrfs_fs_info *fs_info = rc->fs_info;

    while (atomic_read(&rc->elems)) {
        if (!atomic_read(&fs_info->reada_works_cnt))
            reada_start_machine(fs_info);
        wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0,
                          (HZ + 9) / 10);
    }
(...)

So the counter "rc->elems" was set to 1 and never decreased to 0, causing
the scrub task to loop forever in that function. Then I used the following
script for drgn to check the readahead requests:

  $ cat dump_reada.py
  import sys
  import drgn
  from drgn import NULL, Object, cast, container_of, execscript, \
      reinterpret, sizeof
  from drgn.helpers.linux import *

  mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1"

  mnt = None
  for mnt in for_each_mount(prog, dst = mnt_path):
      pass

  if mnt is None:
      sys.stderr.write(f'Error: mount point {mnt_path} not found\n')
      sys.exit(1)

  fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info)

  def dump_re(re):
      nzones = re.nzones.value_()
      print(f're at {hex(re.value_())}')
      print(f'\t logical {re.logical.value_()}')
      print(f'\t refcnt {re.refcnt.value_()}')
      print(f'\t nzones {nzones}')
      for i in range(nzones):
          dev = re.zones[i].device
          name = dev.name.str.string_()
          print(f'\t\t dev id {dev.devid.value_()} name {name}')
      print()

  for _, e in radix_tree_for_each(fs_info.reada_tree):
      re = cast('struct reada_extent *', e)
      dump_re(re)

  $ drgn dump_reada.py
  re at 0xffff8f3da9d25ad8
          logical 38928384
          refcnt 1
          nzones 1
                 dev id 0 name b'/dev/sdd'
  $

So there was one readahead extent with a single zone corresponding to the
source device of that last device replace operation logged in dmesg/syslog.
Also the ID of that zone's device was 0 which is a special value set in
the source device of a device replace operation when the operation finishes
(constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()),
confirming again that device /dev/sdd was the source of a device replace
operation.

Normally there should be as many zones in the readahead extent as there are
devices, and I wasn't expecting the extent to be in a block group with a
'single' profile, so I went and confirmed with the following drgn script
that there weren't any single profile block groups:

  $ cat dump_block_groups.py
  import sys
  import drgn
  from drgn import NULL, Object, cast, container_of, execscript, \
      reinterpret, sizeof
  from drgn.helpers.linux import *

  mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1"

  mnt = None
  for mnt in for_each_mount(prog, dst = mnt_path):
      pass

  if mnt is None:
      sys.stderr.write(f'Error: mount point {mnt_path} not found\n')
      sys.exit(1)

  fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info)

  BTRFS_BLOCK_GROUP_DATA = (1 << 0)
  BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1)
  BTRFS_BLOCK_GROUP_METADATA = (1 << 2)
  BTRFS_BLOCK_GROUP_RAID0 = (1 << 3)
  BTRFS_BLOCK_GROUP_RAID1 = (1 << 4)
  BTRFS_BLOCK_GROUP_DUP = (1 << 5)
  BTRFS_BLOCK_GROUP_RAID10 = (1 << 6)
  BTRFS_BLOCK_GROUP_RAID5 = (1 << 7)
  BTRFS_BLOCK_GROUP_RAID6 = (1 << 8)
  BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9)
  BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10)

  def bg_flags_string(bg):
      flags = bg.flags.value_()
      ret = ''
      if flags & BTRFS_BLOCK_GROUP_DATA:
          ret = 'data'
      if flags & BTRFS_BLOCK_GROUP_METADATA:
          if len(ret) > 0:
              ret += '|'
          ret += 'meta'
      if flags & BTRFS_BLOCK_GROUP_SYSTEM:
          if len(ret) > 0:
              ret += '|'
          ret += 'system'
      if flags & BTRFS_BLOCK_GROUP_RAID0:
          ret += ' raid0'
      elif flags & BTRFS_BLOCK_GROUP_RAID1:
          ret += ' raid1'
      elif flags & BTRFS_BLOCK_GROUP_DUP:
          ret += ' dup'
      elif flags & BTRFS_BLOCK_GROUP_RAID10:
          ret += ' raid10'
      elif flags & BTRFS_BLOCK_GROUP_RAID5:
          ret += ' raid5'
      elif flags & BTRFS_BLOCK_GROUP_RAID6:
          ret += ' raid6'
      elif flags & BTRFS_BLOCK_GROUP_RAID1C3:
          ret += ' raid1c3'
      elif flags & BTRFS_BLOCK_GROUP_RAID1C4:
          ret += ' raid1c4'
      else:
          ret += ' single'

      return ret

  def dump_bg(bg):
      print()
      print(f'block group at {hex(bg.value_())}')
      print(f'\t start {bg.start.value_()} length {bg.length.value_()}')
      print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}')

  bg_root = fs_info.block_group_cache_tree.address_of_()
  for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'):
      dump_bg(bg)

  $ drgn dump_block_groups.py

  block group at 0xffff8f3d673b0400
         start 22020096 length 16777216
         flags 258 - system raid6

  block group at 0xffff8f3d53ddb400
         start 38797312 length 536870912
         flags 260 - meta raid6

  block group at 0xffff8f3d5f4d9c00
         start 575668224 length 2147483648
         flags 257 - data raid6

  block group at 0xffff8f3d08189000
         start 2723151872 length 67108864
         flags 258 - system raid6

  block group at 0xffff8f3db70ff000
         start 2790260736 length 1073741824
         flags 260 - meta raid6

  block group at 0xffff8f3d5f4dd800
         start 3864002560 length 67108864
         flags 258 - system raid6

  block group at 0xffff8f3d67037000
         start 3931111424 length 2147483648
         flags 257 - data raid6
  $

So there were only 2 reasons left for having a readahead extent with a
single zone: reada_find_zone(), called when creating a readahead extent,
returned NULL either because we failed to find the corresponding block
group or because a memory allocation failed. With some additional and
custom tracing I figured out that on every further ocurrence of the
problem the block group had just been deleted when we were looping to
create the zones for the readahead extent (at reada_find_extent()), so we
ended up with only one zone in the readahead extent, corresponding to a
device that ends up getting replaced.

So after figuring that out it became obvious why the hang happens:

1) Task A starts a scrub on any device of the filesystem, except for
   device /dev/sdd;

2) Task B starts a device replace with /dev/sdd as the source device;

3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently
   starting to scrub a stripe from block group X. This call to
   btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add()
   calls reada_add_block(), it passes the logical address of the extent
   tree's root node as its 'logical' argument - a value of 38928384;

4) Task A then enters reada_find_extent(), called from reada_add_block().
   It finds there isn't any existing readahead extent for the logical
   address 38928384, so it proceeds to the path of creating a new one.

   It calls btrfs_map_block() to find out which stripes exist for the block
   group X. On the first iteration of the for loop that iterates over the
   stripes, it finds the stripe for device /dev/sdd, so it creates one
   zone for that device and adds it to the readahead extent. Before getting
   into the second iteration of the loop, the cleanup kthread deletes block
   group X because it was empty. So in the iterations for the remaining
   stripes it does not add more zones to the readahead extent, because the
   calls to reada_find_zone() returned NULL because they couldn't find
   block group X anymore.

   As a result the new readahead extent has a single zone, corresponding to
   the device /dev/sdd;

4) Before task A returns to btrfs_reada_add() and queues the readahead job
   for the readahead work queue, task B finishes the device replace and at
   btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new
   device /dev/sdg;

5) Task A returns to reada_add_block(), which increments the counter
   "->elems" of the reada_control structure allocated at btrfs_reada_add().

   Then it returns back to btrfs_reada_add() and calls
   reada_start_machine(). This queues a job in the readahead work queue to
   run the function reada_start_machine_worker(), which calls
   __reada_start_machine().

   At __reada_start_machine() we take the device list mutex and for each
   device found in the current device list, we call
   reada_start_machine_dev() to start the readahead work. However at this
   point the device /dev/sdd was already freed and is not in the device
   list anymore.

   This means the corresponding readahead for the extent at 38928384 is
   never started, and therefore the "->elems" counter of the reada_control
   structure allocated at btrfs_reada_add() never goes down to 0, causing
   the call to btrfs_reada_wait(), done by the scrub task, to wait forever.

Note that the readahead request can be made either after the device replace
started or before it started, however in pratice it is very unlikely that a
device replace is able to start after a readahead request is made and is
able to complete before the readahead request completes - maybe only on a
very small and nearly empty filesystem.

This hang however is not the only problem we can have with readahead and
device removals. When the readahead extent has other zones other than the
one corresponding to the device that is being removed (either by a device
replace or a device remove operation), we risk having a use-after-free on
the device when dropping the last reference of the readahead extent.

For example if we create a readahead extent with two zones, one for the
device /dev/sdd and one for the device /dev/sde:

1) Before the readahead worker starts, the device /dev/sdd is removed,
   and the corresponding btrfs_device structure is freed. However the
   readahead extent still has the zone pointing to the device structure;

2) When the readahead worker starts, it only finds device /dev/sde in the
   current device list of the filesystem;

3) It starts the readahead work, at reada_start_machine_dev(), using the
   device /dev/sde;

4) Then when it finishes reading the extent from device /dev/sde, it calls
   __readahead_hook() which ends up dropping the last reference on the
   readahead extent through the last call to reada_extent_put();

5) At reada_extent_put() it iterates over each zone of the readahead extent
   and attempts to delete an element from the device's 'reada_extents'
   radix tree, resulting in a use-after-free, as the device pointer of the
   zone for /dev/sdd is now stale. We can also access the device after
   dropping the last reference of a zone, through reada_zone_release(),
   also called by reada_extent_put().

And a device remove suffers the same problem, however since it shrinks the
device size down to zero before removing the device, it is very unlikely to
still have readahead requests not completed by the time we free the device,
the only possibility is if the device has a very little space allocated.

While the hang problem is exclusive to scrub, since it is currently the
only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free
problem affects any path that triggers readhead, which includes
btree_readahead_hook() and __readahead_hook() (a readahead worker can
trigger readahed for the children of a node) for example - any path that
ends up calling reada_add_block() can trigger the use-after-free after a
device is removed.

So fix this by waiting for any readahead requests for a device to complete
before removing a device, ensuring that while waiting for existing ones no
new ones can be made.

This problem has been around for a very long time - the readahead code was
added in 2011, device remove exists since 2008 and device replace was
introduced in 2013, hard to pick a specific commit for a git Fixes tag.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
gratian referenced this pull request in gratian/linux Nov 4, 2020
When enabling qgroups we walk the tree_root and then add a qgroup item
for every root that we have.  This creates a lock dependency on the
tree_root and qgroup_root, which results in the following lockdep splat
(with tree locks using rwsem), eg. in tests btrfs/017 or btrfs/022:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.9.0-default+ #1299 Not tainted
  ------------------------------------------------------
  btrfs/24552 is trying to acquire lock:
  ffff9142dfc5f630 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]

  but task is already holding lock:
  ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (btrfs-root-00){++++}-{3:3}:
	 __lock_acquire+0x3fb/0x730
	 lock_acquire.part.0+0x6a/0x130
	 down_read_nested+0x46/0x130
	 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
	 __btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
	 btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
	 btrfs_search_slot+0xc3/0x9f0 [btrfs]
	 btrfs_insert_item+0x6e/0x140 [btrfs]
	 btrfs_create_tree+0x1cb/0x240 [btrfs]
	 btrfs_quota_enable+0xcd/0x790 [btrfs]
	 btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
	 __x64_sys_ioctl+0x83/0xa0
	 do_syscall_64+0x2d/0x70
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (btrfs-quota-00){++++}-{3:3}:
	 check_prev_add+0x91/0xc30
	 validate_chain+0x491/0x750
	 __lock_acquire+0x3fb/0x730
	 lock_acquire.part.0+0x6a/0x130
	 down_read_nested+0x46/0x130
	 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
	 __btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
	 btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
	 btrfs_search_slot+0xc3/0x9f0 [btrfs]
	 btrfs_insert_empty_items+0x58/0xa0 [btrfs]
	 add_qgroup_item.part.0+0x72/0x210 [btrfs]
	 btrfs_quota_enable+0x3bb/0x790 [btrfs]
	 btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
	 __x64_sys_ioctl+0x83/0xa0
	 do_syscall_64+0x2d/0x70
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-root-00);
				 lock(btrfs-quota-00);
				 lock(btrfs-root-00);
    lock(btrfs-quota-00);

   *** DEADLOCK ***

  5 locks held by btrfs/24552:
   #0: ffff9142df431478 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0xa0
   #1: ffff9142f9b10cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl_quota_ctl+0x7b/0xe0 [btrfs]
   #2: ffff9142f9b11a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0x790 [btrfs]
   #3: ffff9142df431698 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x406/0x510 [btrfs]
   #4: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]

  stack backtrace:
  CPU: 1 PID: 24552 Comm: btrfs Not tainted 5.9.0-default+ #1299
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   dump_stack+0x77/0x97
   check_noncircular+0xf3/0x110
   check_prev_add+0x91/0xc30
   validate_chain+0x491/0x750
   __lock_acquire+0x3fb/0x730
   lock_acquire.part.0+0x6a/0x130
   ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
   ? lock_acquire+0xc4/0x140
   ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
   down_read_nested+0x46/0x130
   ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
   __btrfs_tree_read_lock+0x35/0x1c0 [btrfs]
   ? btrfs_root_node+0xd9/0x200 [btrfs]
   __btrfs_read_lock_root_node+0x3a/0x50 [btrfs]
   btrfs_search_slot_get_root+0x11d/0x290 [btrfs]
   btrfs_search_slot+0xc3/0x9f0 [btrfs]
   btrfs_insert_empty_items+0x58/0xa0 [btrfs]
   add_qgroup_item.part.0+0x72/0x210 [btrfs]
   btrfs_quota_enable+0x3bb/0x790 [btrfs]
   btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs]
   __x64_sys_ioctl+0x83/0xa0
   do_syscall_64+0x2d/0x70
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by dropping the path whenever we find a root item, add the
qgroup item, and then re-lookup the root item we found and continue
processing roots.

Reported-by: David Sterba <dsterba@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
@chaitu236 chaitu236 deleted the dev/fix_objtool_build branch November 11, 2020 22:51
gratian referenced this pull request in gratian/linux Nov 17, 2020
The two commits below add up to a cpuset might_sleep() splat for RT:

8447a0f cpuset: convert callback_mutex to a spinlock
344736f cpuset: simplify cpuset_node_allowed API

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 1, pid: 11718, name: cset
CPU: 135 PID: 11718 Comm: cset Tainted: G            E   4.10.0-rt1-rt #4
Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
Call Trace:
 ? dump_stack+0x5c/0x81
 ? ___might_sleep+0xf4/0x170
 ? rt_spin_lock+0x1c/0x50
 ? __cpuset_node_allowed+0x66/0xc0
 ? ___slab_alloc+0x390/0x570 <disables IRQs>
 ? anon_vma_fork+0x8f/0x140
 ? copy_page_range+0x6cf/0xb00
 ? anon_vma_fork+0x8f/0x140
 ? __slab_alloc.isra.74+0x5a/0x81
 ? anon_vma_fork+0x8f/0x140
 ? kmem_cache_alloc+0x1b5/0x1f0
 ? anon_vma_fork+0x8f/0x140
 ? copy_process.part.35+0x1670/0x1ee0
 ? _do_fork+0xdd/0x3f0
 ? _do_fork+0xdd/0x3f0
 ? do_syscall_64+0x61/0x170
 ? entry_SYSCALL64_slow_path+0x25/0x25

The later ensured that a NUMA box WILL take callback_lock in atomic
context by removing the allocator and reclaim path __GFP_HARDWALL
usage which prevented such contexts from taking callback_mutex.

One option would be to reinstate __GFP_HARDWALL protections for
RT, however, as the 8447a0f changelog states:

The callback_mutex is only used to synchronize reads/updates of cpusets'
flags and cpu/node masks. These operations should always proceed fast so
there's no reason why we can't use a spinlock instead of the mutex.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
gratian pushed a commit that referenced this pull request Dec 1, 2020
When requeueing all requests on the device request queue to the blocklayer
we might get to an ERP (error recovery) request that is a copy of an
original CQR.

Those requests do not have blocklayer request information or a pointer to
the dasd_queue set. When trying to access those data it will lead to a
null pointer dereference in dasd_requeue_all_requests().

Fix by checking if the request is an ERP request that can simply be
ignored. The blocklayer request will be requeued by the original CQR that
is on the device queue right behind the ERP request.

Fixes: 9487cfd ("s390/dasd: fix handling of internal requests")
Cc: <stable@vger.kernel.org> #4.16
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
gratian pushed a commit that referenced this pull request Dec 1, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
gratian pushed a commit that referenced this pull request Dec 1, 2020
Actually, burst size is equal to '1 << desc->rqcfg.brst_size'.
we should use burst size, not desc->rqcfg.brst_size.

dma memcpy performance on Rockchip RV1126
@ 1512MHz A7, 1056MHz LPDDR3, 200MHz DMA:

dmatest:

/# echo dma0chan0 > /sys/module/dmatest/parameters/channel
/# echo 4194304 > /sys/module/dmatest/parameters/test_buf_size
/# echo 8 > /sys/module/dmatest/parameters/iterations
/# echo y > /sys/module/dmatest/parameters/norandom
/# echo y > /sys/module/dmatest/parameters/verbose
/# echo 1 > /sys/module/dmatest/parameters/run

dmatest: dma0chan0-copy0: result #1: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #2: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #3: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #4: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #5: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #6: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #7: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #8: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000

Before:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 48 iops 200338 KB/s (0)

After this patch:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 179 iops 734873 KB/s (0)

After this patch and increase dma clk to 400MHz:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 259 iops 1062929 KB/s (0)

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Link: https://lore.kernel.org/r/1605326106-55681-1-git-send-email-sugar.zhang@rock-chips.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
gratian pushed a commit that referenced this pull request Dec 1, 2020
adapter->tx_scrq and adapter->rx_scrq could be NULL if the previous reset
did not complete after freeing sub crqs. Check for NULL before
dereferencing them.

Snippet of call trace:
ibmvnic 30000006 env6: Releasing sub-CRQ
ibmvnic 30000006 env6: Releasing CRQ
...
ibmvnic 30000006 env6: Got Control IP offload Response
ibmvnic 30000006 env6: Re-setting tx_scrq[0]
BUG: Kernel NULL pointer dereference on read at 0x00000000
Faulting instruction address: 0xc008000003dea7cc
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag tun bridge stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmvnic ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod
CPU: 80 PID: 1856 Comm: kworker/80:2 Tainted: G        W         5.8.0+ #4
Workqueue: events __ibmvnic_reset [ibmvnic]
NIP:  c008000003dea7cc LR: c008000003dea7bc CTR: 0000000000000000
REGS: c0000007ef7db860 TRAP: 0380   Tainted: G        W          (5.8.0+)
MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 28002422  XER: 0000000d
CFAR: c000000000bd9520 IRQMASK: 0
GPR00: c008000003dea7bc c0000007ef7dbaf0 c008000003df7400 c0000007fa26ec00
GPR04: c0000007fcd0d008 c0000007fcd96350 0000000000000027 c0000007fcd0d010
GPR08: 0000000000000023 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000002000 c00000001ec18e00 c0000000001982f8 c0000007bad6e840
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 fffffffffffffef7
GPR24: 0000000000000402 c0000007fa26f3a8 0000000000000003 c00000016f8ec048
GPR28: 0000000000000000 0000000000000000 0000000000000000 c0000007fa26ec00
NIP [c008000003dea7cc] ibmvnic_reset_init+0x15c/0x258 [ibmvnic]
LR [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic]
Call Trace:
[c0000007ef7dbaf0] [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] (unreliable)
[c0000007ef7dbb80] [c008000003de8860] __ibmvnic_reset+0x408/0x970 [ibmvnic]
[c0000007ef7dbc50] [c00000000018b7cc] process_one_work+0x2cc/0x800
[c0000007ef7dbd20] [c00000000018bd78] worker_thread+0x78/0x520
[c0000007ef7dbdb0] [c0000000001984c4] kthread+0x1d4/0x1e0
[c0000007ef7dbe20] [c00000000000cea8] ret_from_kernel_thread+0x5c/0x74

Fixes: 57a4943 ("ibmvnic: Reset sub-crqs during driver reset")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gratian pushed a commit that referenced this pull request Dec 1, 2020
…/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm64 fixes for v5.10, take #4

- Fix alignment of the new HYP sections
- Fix GICR_TYPER access from userspace
gratian referenced this pull request in gratian/linux Dec 8, 2020
[ Upstream commit d26383d ]

The following leaks were detected by ASAN:

  Indirect leak of 360 byte(s) in 9 object(s) allocated from:
    #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
    #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
    #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
    #4 0x560578e07045 in test__pmu tests/pmu.c:155
    #5 0x560578de109b in run_test tests/builtin-test.c:410
    ni#6 0x560578de109b in test_and_print tests/builtin-test.c:440
    ni#7 0x560578de401a in __cmd_test tests/builtin-test.c:661
    ni#8 0x560578de401a in cmd_test tests/builtin-test.c:807
    ni#9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    ni#10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    ni#11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    ni#12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    ni#13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: cff7f95 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2020
[ Upstream commit 71a174b ]

b6da31b "tty: Fix data race in tty_insert_flip_string_fixed_flag"
puts tty_flip_buffer_push under port->lock introducing the following
possible circular locking dependency:

[30129.876566] ======================================================
[30129.876566] WARNING: possible circular locking dependency detected
[30129.876567] 5.9.0-rc2+ #3 Tainted: G S      W
[30129.876568] ------------------------------------------------------
[30129.876568] sysrq.sh/1222 is trying to acquire lock:
[30129.876569] ffffffff92c39480 (console_owner){....}-{0:0}, at: console_unlock+0x3fe/0xa90

[30129.876572] but task is already holding lock:
[30129.876572] ffff888107cb9018 (&pool->lock/1){-.-.}-{2:2}, at: show_workqueue_state.cold.55+0x15b/0x6ca

[30129.876576] which lock already depends on the new lock.

[30129.876577] the existing dependency chain (in reverse order) is:

[30129.876578] -> #3 (&pool->lock/1){-.-.}-{2:2}:
[30129.876581]        _raw_spin_lock+0x30/0x70
[30129.876581]        __queue_work+0x1a3/0x10f0
[30129.876582]        queue_work_on+0x78/0x80
[30129.876582]        pty_write+0x165/0x1e0
[30129.876583]        n_tty_write+0x47f/0xf00
[30129.876583]        tty_write+0x3d6/0x8d0
[30129.876584]        vfs_write+0x1a8/0x650

[30129.876588] -> #2 (&port->lock#2){-.-.}-{2:2}:
[30129.876590]        _raw_spin_lock_irqsave+0x3b/0x80
[30129.876591]        tty_port_tty_get+0x1d/0xb0
[30129.876592]        tty_port_default_wakeup+0xb/0x30
[30129.876592]        serial8250_tx_chars+0x3d6/0x970
[30129.876593]        serial8250_handle_irq.part.12+0x216/0x380
[30129.876593]        serial8250_default_handle_irq+0x82/0xe0
[30129.876594]        serial8250_interrupt+0xdd/0x1b0
[30129.876595]        __handle_irq_event_percpu+0xfc/0x850

[30129.876602] -> #1 (&port->lock){-.-.}-{2:2}:
[30129.876605]        _raw_spin_lock_irqsave+0x3b/0x80
[30129.876605]        serial8250_console_write+0x12d/0x900
[30129.876606]        console_unlock+0x679/0xa90
[30129.876606]        register_console+0x371/0x6e0
[30129.876607]        univ8250_console_init+0x24/0x27
[30129.876607]        console_init+0x2f9/0x45e

[30129.876609] -> #0 (console_owner){....}-{0:0}:
[30129.876611]        __lock_acquire+0x2f70/0x4e90
[30129.876612]        lock_acquire+0x1ac/0xad0
[30129.876612]        console_unlock+0x460/0xa90
[30129.876613]        vprintk_emit+0x130/0x420
[30129.876613]        printk+0x9f/0xc5
[30129.876614]        show_pwq+0x154/0x618
[30129.876615]        show_workqueue_state.cold.55+0x193/0x6ca
[30129.876615]        __handle_sysrq+0x244/0x460
[30129.876616]        write_sysrq_trigger+0x48/0x4a
[30129.876616]        proc_reg_write+0x1a6/0x240
[30129.876617]        vfs_write+0x1a8/0x650

[30129.876619] other info that might help us debug this:

[30129.876620] Chain exists of:
[30129.876621]   console_owner --> &port->lock#2 --> &pool->lock/1

[30129.876625]  Possible unsafe locking scenario:

[30129.876626]        CPU0                    CPU1
[30129.876626]        ----                    ----
[30129.876627]   lock(&pool->lock/1);
[30129.876628]                                lock(&port->lock#2);
[30129.876630]                                lock(&pool->lock/1);
[30129.876631]   lock(console_owner);

[30129.876633]  *** DEADLOCK ***

[30129.876634] 5 locks held by sysrq.sh/1222:
[30129.876634]  #0: ffff8881d3ce0470 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x359/0x650
[30129.876637]  #1: ffffffff92c612c0 (rcu_read_lock){....}-{1:2}, at: __handle_sysrq+0x4d/0x460
[30129.876640]  #2: ffffffff92c612c0 (rcu_read_lock){....}-{1:2}, at: show_workqueue_state+0x5/0xf0
[30129.876642]  #3: ffff888107cb9018 (&pool->lock/1){-.-.}-{2:2}, at: show_workqueue_state.cold.55+0x15b/0x6ca
[30129.876645]  #4: ffffffff92c39980 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x123/0x420

[30129.876648] stack backtrace:
[30129.876649] CPU: 3 PID: 1222 Comm: sysrq.sh Tainted: G S      W         5.9.0-rc2+ #3
[30129.876649] Hardware name: Intel Corporation 2012 Client Platform/Emerald Lake 2, BIOS ACRVMBY1.86C.0078.P00.1201161002 01/16/2012
[30129.876650] Call Trace:
[30129.876650]  dump_stack+0x9d/0xe0
[30129.876651]  check_noncircular+0x34f/0x410
[30129.876653]  __lock_acquire+0x2f70/0x4e90
[30129.876656]  lock_acquire+0x1ac/0xad0
[30129.876658]  console_unlock+0x460/0xa90
[30129.876660]  vprintk_emit+0x130/0x420
[30129.876660]  printk+0x9f/0xc5
[30129.876661]  show_pwq+0x154/0x618
[30129.876662]  show_workqueue_state.cold.55+0x193/0x6ca
[30129.876664]  __handle_sysrq+0x244/0x460
[30129.876665]  write_sysrq_trigger+0x48/0x4a
[30129.876665]  proc_reg_write+0x1a6/0x240
[30129.876666]  vfs_write+0x1a8/0x650

It looks like the commit was aimed to protect tty_insert_flip_string and
there is no need for tty_flip_buffer_push to be under this lock.

Fixes: b6da31b ("tty: Fix data race in tty_insert_flip_string_fixed_flag")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20200902120045.3693075-1-asavkov@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2020
[ Upstream commit ca10845 ]

While running btrfs/061, btrfs/073, btrfs/078, or btrfs/178 we hit the
following lockdep splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.9.0-rc3+ #4 Not tainted
  ------------------------------------------------------
  kswapd0/100 is trying to acquire lock:
  ffff96ecc22ef4a0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x330

  but task is already holding lock:
  ffffffff8dd74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #3 (fs_reclaim){+.+.}-{0:0}:
	 fs_reclaim_acquire+0x65/0x80
	 slab_pre_alloc_hook.constprop.0+0x20/0x200
	 kmem_cache_alloc+0x37/0x270
	 alloc_inode+0x82/0xb0
	 iget_locked+0x10d/0x2c0
	 kernfs_get_inode+0x1b/0x130
	 kernfs_get_tree+0x136/0x240
	 sysfs_get_tree+0x16/0x40
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x434/0xc00
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (kernfs_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x7e/0x7e0
	 kernfs_add_one+0x23/0x150
	 kernfs_create_link+0x63/0xa0
	 sysfs_do_create_link_sd+0x5e/0xd0
	 btrfs_sysfs_add_devices_dir+0x81/0x130
	 btrfs_init_new_device+0x67f/0x1250
	 btrfs_ioctl+0x1ef/0x2e20
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x7e/0x7e0
	 btrfs_chunk_alloc+0x125/0x3a0
	 find_free_extent+0xdf6/0x1210
	 btrfs_reserve_extent+0xb3/0x1b0
	 btrfs_alloc_tree_block+0xb0/0x310
	 alloc_tree_block_no_bg_flush+0x4a/0x60
	 __btrfs_cow_block+0x11a/0x530
	 btrfs_cow_block+0x104/0x220
	 btrfs_search_slot+0x52e/0x9d0
	 btrfs_insert_empty_items+0x64/0xb0
	 btrfs_insert_delayed_items+0x90/0x4f0
	 btrfs_commit_inode_delayed_items+0x93/0x140
	 btrfs_log_inode+0x5de/0x2020
	 btrfs_log_inode_parent+0x429/0xc90
	 btrfs_log_new_name+0x95/0x9b
	 btrfs_rename2+0xbb9/0x1800
	 vfs_rename+0x64f/0x9f0
	 do_renameat2+0x320/0x4e0
	 __x64_sys_rename+0x1f/0x30
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
	 __lock_acquire+0x119c/0x1fc0
	 lock_acquire+0xa7/0x3d0
	 __mutex_lock+0x7e/0x7e0
	 __btrfs_release_delayed_node.part.0+0x3f/0x330
	 btrfs_evict_inode+0x24c/0x500
	 evict+0xcf/0x1f0
	 dispose_list+0x48/0x70
	 prune_icache_sb+0x44/0x50
	 super_cache_scan+0x161/0x1e0
	 do_shrink_slab+0x178/0x3c0
	 shrink_slab+0x17c/0x290
	 shrink_node+0x2b2/0x6d0
	 balance_pgdat+0x30a/0x670
	 kswapd+0x213/0x4c0
	 kthread+0x138/0x160
	 ret_from_fork+0x1f/0x30

  other info that might help us debug this:

  Chain exists of:
    &delayed_node->mutex --> kernfs_mutex --> fs_reclaim

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(fs_reclaim);
				 lock(kernfs_mutex);
				 lock(fs_reclaim);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by kswapd0/100:
   #0: ffffffff8dd74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
   #1: ffffffff8dd65c50 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x115/0x290
   #2: ffff96ed2ade30e0 (&type->s_umount_key#36){++++}-{3:3}, at: super_cache_scan+0x38/0x1e0

  stack backtrace:
  CPU: 0 PID: 100 Comm: kswapd0 Not tainted 5.9.0-rc3+ #4
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x8b/0xb8
   check_noncircular+0x12d/0x150
   __lock_acquire+0x119c/0x1fc0
   lock_acquire+0xa7/0x3d0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   __mutex_lock+0x7e/0x7e0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   ? lock_acquire+0xa7/0x3d0
   ? find_held_lock+0x2b/0x80
   __btrfs_release_delayed_node.part.0+0x3f/0x330
   btrfs_evict_inode+0x24c/0x500
   evict+0xcf/0x1f0
   dispose_list+0x48/0x70
   prune_icache_sb+0x44/0x50
   super_cache_scan+0x161/0x1e0
   do_shrink_slab+0x178/0x3c0
   shrink_slab+0x17c/0x290
   shrink_node+0x2b2/0x6d0
   balance_pgdat+0x30a/0x670
   kswapd+0x213/0x4c0
   ? _raw_spin_unlock_irqrestore+0x41/0x50
   ? add_wait_queue_exclusive+0x70/0x70
   ? balance_pgdat+0x670/0x670
   kthread+0x138/0x160
   ? kthread_create_worker_on_cpu+0x40/0x40
   ret_from_fork+0x1f/0x30

This happens because we are holding the chunk_mutex at the time of
adding in a new device.  However we only need to hold the
device_list_mutex, as we're going to iterate over the fs_devices
devices.  Move the sysfs init stuff outside of the chunk_mutex to get
rid of this lockdep splat.

CC: stable@vger.kernel.org # 4.4.x: f3cd2c5: btrfs: sysfs, rename device_link add/remove functions
CC: stable@vger.kernel.org # 4.4.x
Reported-by: David Sterba <dsterba@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2020
commit 6f117cb upstream.

When requeueing all requests on the device request queue to the blocklayer
we might get to an ERP (error recovery) request that is a copy of an
original CQR.

Those requests do not have blocklayer request information or a pointer to
the dasd_queue set. When trying to access those data it will lead to a
null pointer dereference in dasd_requeue_all_requests().

Fix by checking if the request is an ERP request that can simply be
ignored. The blocklayer request will be requeued by the original CQR that
is on the device queue right behind the ERP request.

Fixes: 9487cfd ("s390/dasd: fix handling of internal requests")
Cc: <stable@vger.kernel.org> #4.16
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 11, 2021
[ Upstream commit d715ff8 ]

The purpose of srv_mutex is to protect srv_list as in put_srv, so no need
to hold it when allocate memory for srv since it could be time consuming.

Otherwise if one machine has limited memory, rsrv_close_work could be
blocked for a longer time due to the mutex is held by get_or_create_srv
since it can't get memory in time.

  INFO: task kworker/1:1:27478 blocked for more than 120 seconds.
        Tainted: G           O    4.14.171-1-storage #4.14.171-1.3~deb9
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  kworker/1:1     D    0 27478      2 0x80000000
  Workqueue: rtrs_server_wq rtrs_srv_close_work [rtrs_server]
  Call Trace:
   ? __schedule+0x38c/0x7e0
   schedule+0x32/0x80
   schedule_preempt_disabled+0xa/0x10
   __mutex_lock.isra.2+0x25e/0x4d0
   ? put_srv+0x44/0x100 [rtrs_server]
   put_srv+0x44/0x100 [rtrs_server]
   rtrs_srv_close_work+0x16c/0x280 [rtrs_server]
   process_one_work+0x1c5/0x3c0
   worker_thread+0x47/0x3e0
   kthread+0xfc/0x130
   ? trace_event_raw_event_workqueue_execute_start+0xa0/0xa0
   ? kthread_create_on_node+0x70/0x70
   ret_from_fork+0x1f/0x30

Let's move all the logics from __find_srv_and_get and __alloc_srv to
get_or_create_srv, and remove the two functions. Then it should be safe
for multiple processes to access the same srv since it is protected with
srv_mutex.

And since we don't want to allocate chunks with srv_mutex held, let's
check the srv->refcount after get srv because the chunks could not be
allocated yet.

Fixes: 9cb8374 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20201023074353.21946-6-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Jan 11, 2021
[ Upstream commit 4a9d81c ]

If the elem is deleted during be iterated on it, the iteration
process will fall into an endless loop.

kernel: NMI watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [nfsd:17137]

PID: 17137  TASK: ffff8818d93c0000  CPU: 4   COMMAND: "nfsd"
    [exception RIP: __state_in_grace+76]
    RIP: ffffffffc00e817c  RSP: ffff8818d3aefc98  RFLAGS: 00000246
    RAX: ffff881dc0c38298  RBX: ffffffff81b03580  RCX: ffff881dc02c9f50
    RDX: ffff881e3fce8500  RSI: 0000000000000001  RDI: ffffffff81b03580
    RBP: ffff8818d3aefca0   R8: 0000000000000020   R9: ffff8818d3aefd40
    R10: ffff88017fc03800  R11: ffff8818e83933c0  R12: ffff8818d3aefd40
    R13: 0000000000000000  R14: ffff8818e8391068  R15: ffff8818fa6e4000
    CS: 0010  SS: 0018
 #0 [ffff8818d3aefc98] opens_in_grace at ffffffffc00e81e3 [grace]
 #1 [ffff8818d3aefca8] nfs4_preprocess_stateid_op at ffffffffc02a3e6c [nfsd]
 #2 [ffff8818d3aefd18] nfsd4_write at ffffffffc028ed5b [nfsd]
 #3 [ffff8818d3aefd80] nfsd4_proc_compound at ffffffffc0290a0d [nfsd]
 #4 [ffff8818d3aefdd0] nfsd_dispatch at ffffffffc027b800 [nfsd]
 #5 [ffff8818d3aefe08] svc_process_common at ffffffffc02017f3 [sunrpc]
 #6 [ffff8818d3aefe70] svc_process at ffffffffc0201ce3 [sunrpc]
 #7 [ffff8818d3aefe98] nfsd at ffffffffc027b117 [nfsd]
 #8 [ffff8818d3aefec8] kthread at ffffffff810b88c1
 #9 [ffff8818d3aeff50] ret_from_fork at ffffffff816d1607

The troublemake elem:
crash> lock_manager ffff881dc0c38298
struct lock_manager {
  list = {
    next = 0xffff881dc0c38298,
    prev = 0xffff881dc0c38298
  },
  block_opens = false
}

Fixes: c87fb4a ("lockd: NLM grace period shouldn't block NFSv4 opens")
Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Jan 11, 2021
commit 00c3348 upstream.

Mismatch in probe platform_set_drvdata set's and method's that call
dev_get_platdata will result in "Unable to handle kernel NULL pointer
dereference", let's use according method for getting driver data after
platform_set_drvdata.

8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = (ptrval)
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.10-00003-g723e101e0037-dirty #4
Hardware name: Technologic Systems TS-72xx SBC
PC is at ep93xx_rtc_read_time+0xc/0x2c
LR is at __rtc_read_time+0x4c/0x8c
[...]
[<c02b01c8>] (ep93xx_rtc_read_time) from [<c02ac38c>] (__rtc_read_time+0x4c/0x8c)
[<c02ac38c>] (__rtc_read_time) from [<c02ac3f8>] (rtc_read_time+0x2c/0x4c)
[<c02ac3f8>] (rtc_read_time) from [<c02acc54>] (__rtc_read_alarm+0x28/0x358)
[<c02acc54>] (__rtc_read_alarm) from [<c02abd80>] (__rtc_register_device+0x124/0x2ec)
[<c02abd80>] (__rtc_register_device) from [<c02b028c>] (ep93xx_rtc_probe+0xa4/0xac)
[<c02b028c>] (ep93xx_rtc_probe) from [<c026424c>] (platform_drv_probe+0x24/0x5c)
[<c026424c>] (platform_drv_probe) from [<c0262918>] (really_probe+0x218/0x374)
[<c0262918>] (really_probe) from [<c0262da0>] (device_driver_attach+0x44/0x60)
[<c0262da0>] (device_driver_attach) from [<c0262e70>] (__driver_attach+0xb4/0xc0)
[<c0262e70>] (__driver_attach) from [<c0260d44>] (bus_for_each_dev+0x68/0xac)
[<c0260d44>] (bus_for_each_dev) from [<c026223c>] (driver_attach+0x18/0x24)
[<c026223c>] (driver_attach) from [<c0261dd8>] (bus_add_driver+0x150/0x1b4)
[<c0261dd8>] (bus_add_driver) from [<c026342c>] (driver_register+0xb0/0xf4)
[<c026342c>] (driver_register) from [<c0264210>] (__platform_driver_register+0x30/0x48)
[<c0264210>] (__platform_driver_register) from [<c04cb9ac>] (ep93xx_rtc_driver_init+0x10/0x1c)
[<c04cb9ac>] (ep93xx_rtc_driver_init) from [<c000973c>] (do_one_initcall+0x7c/0x1c0)
[<c000973c>] (do_one_initcall) from [<c04b9ecc>] (kernel_init_freeable+0x168/0x1ac)
[<c04b9ecc>] (kernel_init_freeable) from [<c03b2228>] (kernel_init+0x8/0xf4)
[<c03b2228>] (kernel_init) from [<c00082c0>] (ret_from_fork+0x14/0x34)
Exception stack(0xc441dfb0 to 0xc441dff8)
dfa0:                                     00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e12fff1e e92d4010 e590303c e1a02001 (e5933000)
---[ end trace c914d6030eaa95c8 ]---

Fixes: b809d19 ("rtc: ep93xx: stop setting platform_data")
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201201095507.10317-1-nikita.shubin@maquefel.me
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 22, 2021
[ Upstream commit d9e4498 ]

Like other tunneling interfaces, the bareudp doesn't need TXLOCK.
So, It is good to set the NETIF_F_LLTX flag to improve performance and
to avoid lockdep's false-positive warning.

Test commands:
    ip netns add A
    ip netns add B
    ip link add veth0 netns A type veth peer name veth1 netns B
    ip netns exec A ip link set veth0 up
    ip netns exec A ip a a 10.0.0.1/24 dev veth0
    ip netns exec B ip link set veth1 up
    ip netns exec B ip a a 10.0.0.2/24 dev veth1

    for i in {2..1}
    do
            let A=$i-1
            ip netns exec A ip link add bareudp$i type bareudp \
		    dstport $i ethertype ip
            ip netns exec A ip link set bareudp$i up
            ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i
            ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \
		    dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i

            ip netns exec B ip link add bareudp$i type bareudp \
		    dstport $i ethertype ip
            ip netns exec B ip link set bareudp$i up
            ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i
            ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \
		    dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i
    done
    ip netns exec A ping 10.0.2.2

Splat looks like:
[   96.992803][  T822] ============================================
[   96.993954][  T822] WARNING: possible recursive locking detected
[   96.995102][  T822] 5.10.0+ #819 Not tainted
[   96.995927][  T822] --------------------------------------------
[   96.997091][  T822] ping/822 is trying to acquire lock:
[   96.998083][  T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   96.999813][  T822]
[   96.999813][  T822] but task is already holding lock:
[   97.001192][  T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   97.002908][  T822]
[   97.002908][  T822] other info that might help us debug this:
[   97.004401][  T822]  Possible unsafe locking scenario:
[   97.004401][  T822]
[   97.005784][  T822]        CPU0
[   97.006407][  T822]        ----
[   97.007010][  T822]   lock(_xmit_NONE#2);
[   97.007779][  T822]   lock(_xmit_NONE#2);
[   97.008550][  T822]
[   97.008550][  T822]  *** DEADLOCK ***
[   97.008550][  T822]
[   97.010057][  T822]  May be due to missing lock nesting notation
[   97.010057][  T822]
[   97.011594][  T822] 7 locks held by ping/822:
[   97.012426][  T822]  #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00
[   97.014191][  T822]  #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[   97.016045][  T822]  #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[   97.017897][  T822]  #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[   97.019684][  T822]  #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp]
[   97.021573][  T822]  #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[   97.023424][  T822]  #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[   97.025259][  T822]
[   97.025259][  T822] stack backtrace:
[   97.026349][  T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819
[   97.027609][  T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[   97.029407][  T822] Call Trace:
[   97.030015][  T822]  dump_stack+0x99/0xcb
[   97.030783][  T822]  __lock_acquire.cold.77+0x149/0x3a9
[   97.031773][  T822]  ? stack_trace_save+0x81/0xa0
[   97.032661][  T822]  ? register_lock_class+0x1910/0x1910
[   97.033673][  T822]  ? register_lock_class+0x1910/0x1910
[   97.034679][  T822]  ? rcu_read_lock_sched_held+0x91/0xc0
[   97.035697][  T822]  ? rcu_read_lock_bh_held+0xa0/0xa0
[   97.036690][  T822]  lock_acquire+0x1b2/0x730
[   97.037515][  T822]  ? __dev_queue_xmit+0x1f52/0x2960
[   97.038466][  T822]  ? check_flags+0x50/0x50
[   97.039277][  T822]  ? netif_skb_features+0x296/0x9c0
[   97.040226][  T822]  ? validate_xmit_skb+0x29/0xb10
[   97.041151][  T822]  _raw_spin_lock+0x30/0x70
[   97.041977][  T822]  ? __dev_queue_xmit+0x1f52/0x2960
[   97.042927][  T822]  __dev_queue_xmit+0x1f52/0x2960
[   97.043852][  T822]  ? netdev_core_pick_tx+0x290/0x290
[   97.044824][  T822]  ? mark_held_locks+0xb7/0x120
[   97.045712][  T822]  ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
[   97.046824][  T822]  ? __local_bh_enable_ip+0xa5/0xf0
[   97.047771][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.048710][  T822]  ? trace_hardirqs_on+0x41/0x120
[   97.049626][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.050556][  T822]  ? __local_bh_enable_ip+0xa5/0xf0
[   97.051509][  T822]  ? ___neigh_create+0x12a8/0x1eb0
[   97.052443][  T822]  ? check_chain_key+0x244/0x5f0
[   97.053352][  T822]  ? rcu_read_lock_bh_held+0x56/0xa0
[   97.054317][  T822]  ? ip_finish_output2+0x6ea/0x2020
[   97.055263][  T822]  ? pneigh_lookup+0x410/0x410
[   97.056135][  T822]  ip_finish_output2+0x6ea/0x2020
[ ... ]

Acked-by: Guillaume Nault <gnault@redhat.com>
Fixes: 571912c ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 22, 2021
commit 3a21777 upstream.

We had kernel panic, it is caused by unload module and last
close confirmation.

call trace:
[1196029.743127]  free_sess+0x15/0x50 [rtrs_client]
[1196029.743128]  rtrs_clt_close+0x4c/0x70 [rtrs_client]
[1196029.743129]  ? rnbd_clt_unmap_device+0x1b0/0x1b0 [rnbd_client]
[1196029.743130]  close_rtrs+0x25/0x50 [rnbd_client]
[1196029.743131]  rnbd_client_exit+0x93/0xb99 [rnbd_client]
[1196029.743132]  __x64_sys_delete_module+0x190/0x260

And in the crashdump confirmation kworker is also running.
PID: 6943   TASK: ffff9e2ac8098000  CPU: 4   COMMAND: "kworker/4:2"
 #0 [ffffb206cf337c30] __schedule at ffffffff9f93f891
 #1 [ffffb206cf337cc8] schedule at ffffffff9f93fe98
 #2 [ffffb206cf337cd0] schedule_timeout at ffffffff9f943938
 #3 [ffffb206cf337d50] wait_for_completion at ffffffff9f9410a7
 #4 [ffffb206cf337da0] __flush_work at ffffffff9f08ce0e
 #5 [ffffb206cf337e20] rtrs_clt_close_conns at ffffffffc0d5f668 [rtrs_client]
 #6 [ffffb206cf337e48] rtrs_clt_close at ffffffffc0d5f801 [rtrs_client]
 #7 [ffffb206cf337e68] close_rtrs at ffffffffc0d26255 [rnbd_client]
 #8 [ffffb206cf337e78] free_sess at ffffffffc0d262ad [rnbd_client]
 #9 [ffffb206cf337e88] rnbd_clt_put_dev at ffffffffc0d266a7 [rnbd_client]

The problem is both code path try to close same session, which lead to
panic.

To fix it, just skip the sess if the refcount already drop to 0.

Fixes: f7a7a5c ("block/rnbd: client: main functionality")
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 12, 2021
commit caab13b upstream.

Since at91_soc_init is called unconditionally from atmel_soc_device_init,
we get the following warning on all non AT91 SoCs:
	" AT91: Could not find identification node"

Fix the same by filtering with allowed AT91 SoC list.

Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: stable@vger.kernel.org #4.12+
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201211135846.1334322-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 12, 2021
…st[]

commit 6808965 upstream.

of_match_node() calls __of_match_node() which loops though the entries of
matches array. It stops when condition:
(matches->name[0] || matches->type[0] || matches->compatible[0]) is
false. Thus, add a null entry at the end of at91_soc_allowed_list[]
array.

Fixes: caab13b ("drivers: soc: atmel: Avoid calling at91_soc_init on non AT91 SoCs")
Cc: stable@vger.kernel.org #4.12+
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 12, 2021
[ Upstream commit c1c3ba1 ]

If dobj->control is not initialized we end up in an OOPs during
skl_tplg_complete:

[   26.553358] BUG: kernel NULL pointer dereference, address:
0000000000000078
[   26.561151] #PF: supervisor read access in kernel mode
[   26.566897] #PF: error_code(0x0000) - not-present page
[   26.572642] PGD 0 P4D 0
[   26.575479] Oops: 0000 [#1] PREEMPT SMP PTI
[   26.580158] CPU: 2 PID: 2082 Comm: udevd Tainted: G         C
5.4.81 #4
[   26.588232] Hardware name: HP Soraka/Soraka, BIOS
Google_Soraka.10431.106.0 12/03/2019
[   26.597082] RIP: 0010:skl_tplg_complete+0x70/0x144 [snd_soc_skl]

Fixes: 2d744ec ("ASoC: Intel: Skylake: Automatic DMIC format configuration according to information from NHL")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Tested-by: Lukasz Majczak <lma@semihalf.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210121171644.131059-1-ribalda@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Mar 15, 2021
[ Upstream commit 7f9942c ]

Building with the clang integrated assembler produces a couple of
errors for the s3c24xx fiq support:

  arch/arm/mach-s3c/irq-s3c24xx-fiq.S:52:2: error: instruction 'subne' can not set flags, but 's' suffix specified
    subnes pc, lr, #4 @@ return, still have work to do

  arch/arm/mach-s3c/irq-s3c24xx-fiq.S:64:1: error: invalid symbol redefinition
    s3c24xx_spi_fiq_txrx:

There are apparently two problems: one with extraneous or duplicate
labels, and one with old-style opcode mnemonics. Stefan Agner has
previously fixed other problems like this, but missed this particular
file.

Fixes: bec0806 ("spi_s3c24xx: add FIQ pseudo-DMA support")
Cc: Stefan Agner <stefan@agner.ch>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210204162416.3030114-1-arnd@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Mar 15, 2021
[ Upstream commit c5c97ca ]

The ubsan reported the following error.  It was because sample's raw
data missed u32 padding at the end.  So it broke the alignment of the
array after it.

The raw data contains an u32 size prefix so the data size should have
an u32 padding after 8-byte aligned data.

27: Sample parsing  :util/synthetic-events.c:1539:4:
  runtime error: store to misaligned address 0x62100006b9bc for type
  '__u64' (aka 'unsigned long long'), which requires 8 byte alignment
0x62100006b9bc: note: pointer points here
  00 00 00 00 ff ff ff ff  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff
              ^
    #0 0x561532a9fc96 in perf_event__synthesize_sample util/synthetic-events.c:1539:13
    #1 0x5615327f4a4f in do_test tests/sample-parsing.c:284:8
    #2 0x5615327f3f50 in test__sample_parsing tests/sample-parsing.c:381:9
    #3 0x56153279d3a1 in run_test tests/builtin-test.c:424:9
    #4 0x56153279c836 in test_and_print tests/builtin-test.c:454:9
    #5 0x56153279b7eb in __cmd_test tests/builtin-test.c:675:4
    #6 0x56153279abf0 in cmd_test tests/builtin-test.c:821:9
    #7 0x56153264e796 in run_builtin perf.c:312:11
    #8 0x56153264cf03 in handle_internal_command perf.c:364:8
    #9 0x56153264e47d in run_argv perf.c:408:2
    #10 0x56153264c9a9 in main perf.c:538:3
    #11 0x7f137ab6fbbc in __libc_start_main (/lib64/libc.so.6+0x38bbc)
    #12 0x561532596828 in _start ...

SUMMARY: UndefinedBehaviorSanitizer: misaligned-pointer-use
 util/synthetic-events.c:1539:4 in

Fixes: 045f8cd ("perf tests: Add a sample parsing test")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210214091638.519643-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Mar 26, 2021
commit 4d14c5c upstream

Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 #11  touch_atime at ffffffffa4cf0000
 #12  generic_file_read_iter at ffffffffa4c1f123
 #13  new_sync_read at ffffffffa4ccdc8a
 #14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 #17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 #11  extent_write_cache_pages at ffffffffc03a500b
 #12  extent_writepages at ffffffffc03a6de2
 #13  do_writepages at ffffffffa4c277eb
 #14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 #17  process_one_work at ffffffffa4aba4e4
 #18  worker_thread at ffffffffa4aba6fd
 #19  kthread at ffffffffa4ac0a3d
 #20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Mar 26, 2021
commit ac0bbf5 upstream.

The digital input subdevice supports Comedi asynchronous commands that
read interrupt status information.  This uses 16-bit Comedi samples (of
which only the bottom 8 bits contain status information).  However, the
interrupt handler is calling `comedi_buf_write_samples()` with the
address of a 32-bit variable `unsigned int status`.  On a bigendian
machine, this will copy 2 bytes from the wrong end of the variable.  Fix
it by changing the type of the variable to `unsigned short`.

Fixes: a8c66b6 ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <stable@vger.kernel.org> #4.0+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Jul 11, 2024
commit 9d274c1 upstream.

We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():

  BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:2620!
  invalid opcode: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 ni#6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]

With the following stack trace:

  #0  btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
  #1  btrfs_drop_extents (fs/btrfs/file.c:411:4)
  #2  log_one_extent (fs/btrfs/tree-log.c:4732:9)
  #3  btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
  #4  btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
  #5  btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
  ni#6  btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
  ni#7  btrfs_sync_file (fs/btrfs/file.c:1933:8)
  ni#8  vfs_fsync_range (fs/sync.c:188:9)
  ni#9  vfs_fsync (fs/sync.c:202:9)
  ni#10 do_fsync (fs/sync.c:212:9)
  ni#11 __do_sys_fdatasync (fs/sync.c:225:9)
  ni#12 __se_sys_fdatasync (fs/sync.c:223:1)
  ni#13 __x64_sys_fdatasync (fs/sync.c:223:1)
  ni#14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
  ni#15 do_syscall_64 (arch/x86/entry/common.c:83:7)
  ni#16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)

So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().

This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:

  >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
  leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610
  leaf 33439744 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
          item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
                  generation 7 transid 9 size 8192 nbytes 8473563889606862198
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 204 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417704.983333333 (2024-05-22 15:41:44)
                  mtime 1716417704.983333333 (2024-05-22 15:41:44)
                  otime 17592186044416.000000000 (559444-03-08 01:40:16)
          item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
                  index 195 namelen 3 name: 193
          item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 4096 ram 12288
                  extent compression 0 (none)
          item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 4096 nr 8192
          item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096
  ...

So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.

Here is the state of the filesystem tree at the time of the crash:

  >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
  >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
  >>> print_extent_buffer(nodes[0])
  leaf 30425088 level 0 items 184 generation 9 owner 5
  leaf 30425088 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
  	...
          item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
                  generation 7 transid 7 size 4096 nbytes 12288
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 6 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417703.220000000 (2024-05-22 15:41:43)
                  mtime 1716417703.220000000 (2024-05-22 15:41:43)
                  otime 1716417703.220000000 (2024-05-22 15:41:43)
          item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
                  index 195 namelen 3 name: 193
          item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 8192 ram 12288
                  extent compression 0 (none)
          item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096

Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.

btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.

If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.

This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:

- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
  prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
  the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
  to the log tree.
- An xattr is set on the file, which sets the
  BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
  extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
  calls copy_inode_items_to_log(), which calls
  btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
  filesystem tree. Since it starts before i_size, it skips it. Since it
  is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
  the prealloc extent to written and inserts the remaining prealloc part
  from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
  8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
  the log tree. Note that it overlaps with the 4k-12k prealloc extent
  that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
  extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
  adjusting the start of the 4k-12k prealloc extent in the log tree to
  8k.
- btrfs_set_item_key_safe() sees that there is already an extent
  starting at 8k in the log tree and calls BUG().

Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Jul 11, 2024
commit 22f0081 upstream.

The syzbot fuzzer found that the interrupt-URB completion callback in
the cdc-wdm driver was taking too long, and the driver's immediate
resubmission of interrupt URBs with -EPROTO status combined with the
dummy-hcd emulation to cause a CPU lockup:

cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625]
CPU#0 Utilization every 4s during lockup:
	#1:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#2:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#3:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#4:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#5:  98% system,	  1% softirq,	  3% hardirq,	  0% idle
Modules linked in:
irq event stamp: 73096
hardirqs last  enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline]
hardirqs last  enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994
hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last  enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582
softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588
CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G        W          6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024

Testing showed that the problem did not occur if the two error
messages -- the first two lines above -- were removed; apparently adding
material to the kernel log takes a surprisingly large amount of time.

In any case, the best approach for preventing these lockups and to
avoid spamming the log with thousands of error messages per second is
to ratelimit the two dev_err() calls.  Therefore we replace them with
dev_err_ratelimited().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/
Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/
Fixes: 9908a32 ("USB: remove err() macro from usb class drivers")
Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Jul 11, 2024
[ Upstream commit f1e197a ]

trace_drop_common() is called with preemption disabled, and it acquires
a spin_lock. This is problematic for RT kernels because spin_locks are
sleeping locks in this configuration, which causes the following splat:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
5 locks held by rcuc/47/449:
 #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210
 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130
 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210
 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70
 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290
irq event stamp: 139909
hardirqs last  enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80
hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290
softirqs last  enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170
softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0
Preemption disabled at:
[<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0
CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ ni#7
Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022
Call Trace:
 <TASK>
 dump_stack_lvl+0x8c/0xd0
 dump_stack+0x14/0x20
 __might_resched+0x21e/0x2f0
 rt_spin_lock+0x5e/0x130
 ? trace_drop_common.constprop.0+0xb5/0x290
 ? skb_queue_purge_reason.part.0+0x1bf/0x230
 trace_drop_common.constprop.0+0xb5/0x290
 ? preempt_count_sub+0x1c/0xd0
 ? _raw_spin_unlock_irqrestore+0x4a/0x80
 ? __pfx_trace_drop_common.constprop.0+0x10/0x10
 ? rt_mutex_slowunlock+0x26a/0x2e0
 ? skb_queue_purge_reason.part.0+0x1bf/0x230
 ? __pfx_rt_mutex_slowunlock+0x10/0x10
 ? skb_queue_purge_reason.part.0+0x1bf/0x230
 trace_kfree_skb_hit+0x15/0x20
 trace_kfree_skb+0xe9/0x150
 kfree_skb_reason+0x7b/0x110
 skb_queue_purge_reason.part.0+0x1bf/0x230
 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10
 ? mark_lock.part.0+0x8a/0x520
...

trace_drop_common() also disables interrupts, but this is a minor issue
because we could easily replace it with a local_lock.

Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic
context.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reported-by: Hu Chunyu <chuhu@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Jul 11, 2024
[ Upstream commit af0cb3f ]

Xiumei and Christoph reported the following lockdep splat, complaining of
the qdisc root lock being taken twice:

 ============================================
 WARNING: possible recursive locking detected
 6.7.0-rc3+ #598 Not tainted
 --------------------------------------------
 swapper/2/0 is trying to acquire lock:
 ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70

 but task is already holding lock:
 ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&sch->q.lock);
   lock(&sch->q.lock);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 5 locks held by swapper/2/0:
  #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510
  #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0
  #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70
  #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70
  #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70

 stack backtrace:
 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ #598
 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
 Call Trace:
  <IRQ>
  dump_stack_lvl+0x4a/0x80
  __lock_acquire+0xfdd/0x3150
  lock_acquire+0x1ca/0x540
  _raw_spin_lock+0x34/0x80
  __dev_queue_xmit+0x1560/0x2e70
  tcf_mirred_act+0x82e/0x1260 [act_mirred]
  tcf_action_exec+0x161/0x480
  tcf_classify+0x689/0x1170
  prio_enqueue+0x316/0x660 [sch_prio]
  dev_qdisc_enqueue+0x46/0x220
  __dev_queue_xmit+0x1615/0x2e70
  ip_finish_output2+0x1218/0x1ed0
  __ip_finish_output+0x8b3/0x1350
  ip_output+0x163/0x4e0
  igmp_ifc_timer_expire+0x44b/0x930
  call_timer_fn+0x1a2/0x510
  run_timer_softirq+0x54d/0x11a0
  __do_softirq+0x1b3/0x88f
  irq_exit_rcu+0x18f/0x1e0
  sysvec_apic_timer_interrupt+0x6f/0x90
  </IRQ>

This happens when TC does a mirred egress redirect from the root qdisc of
device A to the root qdisc of device B. As long as these two locks aren't
protecting the same qdisc, they can be acquired in chain: add a per-qdisc
lockdep key to silence false warnings.
This dynamic key should safely replace the static key we have in sch_htb:
it was added to allow enqueueing to the device "direct qdisc" while still
holding the qdisc root lock.

v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet)

CC: Maxim Mikityanskiy <maxim@isovalent.com>
CC: Xiumei Mu <xmu@redhat.com>
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: multipath-tcp/mptcp_net-next#451
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Aug 29, 2024
[ Upstream commit b313a8c ]

Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240815024736.2040971-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Sep 11, 2024
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: gnault@redhat.com
CC: cong.wang@bytedance.com
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Sep 11, 2024
[ Upstream commit b313a8c ]

Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240815024736.2040971-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Oct 2, 2024
[ Upstream commit c3a5e3e ]

When using cachefiles, lockdep may emit something similar to the circular
locking dependency notice below.  The problem appears to stem from the
following:

 (1) Cachefiles manipulates xattrs on the files in its cache when called
     from ->writepages().

 (2) The setxattr() and removexattr() system call handlers get the name
     (and value) from userspace after taking the sb_writers lock, putting
     accesses of the vma->vm_lock and mm->mmap_lock inside of that.

 (3) The afs filesystem uses a per-inode lock to prevent multiple
     revalidation RPCs and in writeback vs truncate to prevent parallel
     operations from deadlocking against the server on one side and local
     page locks on the other.

Fix this by moving the getting of the name and value in {get,remove}xattr()
outside of the sb_writers lock.  This also has the minor benefits that we
don't need to reget these in the event of a retry and we never try to take
the sb_writers lock in the event we can't pull the name and value into the
kernel.

Alternative approaches that might fix this include moving the dispatch of a
write to the cache off to a workqueue or trying to do without the
validation lock in afs.  Note that this might also affect other filesystems
that use netfslib and/or cachefiles.

 ======================================================
 WARNING: possible circular locking dependency detected
 6.10.0-build2+ #956 Not tainted
 ------------------------------------------------------
 fsstress/6050 is trying to acquire lock:
 ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0

 but task is already holding lock:
 ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #4 (&vma->vm_lock->lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_write+0x3b/0x50
        vma_start_write+0x6b/0xa0
        vma_link+0xcc/0x140
        insert_vm_struct+0xb7/0xf0
        alloc_bprm+0x2c1/0x390
        kernel_execve+0x65/0x1a0
        call_usermodehelper_exec_async+0x14d/0x190
        ret_from_fork+0x24/0x40
        ret_from_fork_asm+0x1a/0x30

 -> #3 (&mm->mmap_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        __might_fault+0x7c/0xb0
        strncpy_from_user+0x25/0x160
        removexattr+0x7f/0x100
        __do_sys_fremovexattr+0x7e/0xb0
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #2 (sb_writers#14){.+.+}-{0:0}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        percpu_down_read+0x3c/0x90
        vfs_iocb_iter_write+0xe9/0x1d0
        __cachefiles_write+0x367/0x430
        cachefiles_issue_write+0x299/0x2f0
        netfs_advance_write+0x117/0x140
        netfs_write_folio.isra.0+0x5ca/0x6e0
        netfs_writepages+0x230/0x2f0
        afs_writepages+0x4d/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        __filemap_fdatawrite_range+0xa8/0xf0
        file_write_and_wait_range+0x59/0x90
        afs_release+0x10f/0x270
        __fput+0x25f/0x3d0
        __do_sys_close+0x43/0x70
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #1 (&vnode->validate_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        afs_writepages+0x37/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        filemap_invalidate_inode+0x167/0x1e0
        netfs_unbuffered_write_iter+0x1bd/0x2d0
        vfs_write+0x22e/0x320
        ksys_write+0xbc/0x130
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #0 (mapping.invalidate_lock#3){++++}-{3:3}:
        check_noncircular+0x119/0x160
        check_prev_add+0x195/0x430
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        filemap_fault+0x26e/0x8b0
        __do_fault+0x57/0xd0
        do_pte_missing+0x23b/0x320
        __handle_mm_fault+0x2d4/0x320
        handle_mm_fault+0x14f/0x260
        do_user_addr_fault+0x2a2/0x500
        exc_page_fault+0x71/0x90
        asm_exc_page_fault+0x22/0x30

 other info that might help us debug this:

 Chain exists of:
   mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   rlock(&vma->vm_lock->lock);
                                lock(&mm->mmap_lock);
                                lock(&vma->vm_lock->lock);
   rlock(mapping.invalidate_lock#3);

  *** DEADLOCK ***

 1 lock held by fsstress/6050:
  #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 stack backtrace:
 CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ #956
 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x57/0x80
  check_noncircular+0x119/0x160
  ? queued_spin_lock_slowpath+0x4be/0x510
  ? __pfx_check_noncircular+0x10/0x10
  ? __pfx_queued_spin_lock_slowpath+0x10/0x10
  ? mark_lock+0x47/0x160
  ? init_chain_block+0x9c/0xc0
  ? add_chain_block+0x84/0xf0
  check_prev_add+0x195/0x430
  __lock_acquire+0xaf0/0xd80
  ? __pfx___lock_acquire+0x10/0x10
  ? __lock_release.isra.0+0x13b/0x230
  lock_acquire.part.0+0x103/0x280
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_lock_acquire.part.0+0x10/0x10
  ? rcu_is_watching+0x34/0x60
  ? lock_acquire+0xd7/0x120
  down_read+0x95/0x200
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_down_read+0x10/0x10
  ? __filemap_get_folio+0x25/0x1a0
  filemap_fault+0x26e/0x8b0
  ? __pfx_filemap_fault+0x10/0x10
  ? find_held_lock+0x7c/0x90
  ? __pfx___lock_release.isra.0+0x10/0x10
  ? __pte_offset_map+0x99/0x110
  __do_fault+0x57/0xd0
  do_pte_missing+0x23b/0x320
  __handle_mm_fault+0x2d4/0x320
  ? __pfx___handle_mm_fault+0x10/0x10
  handle_mm_fault+0x14f/0x260
  do_user_addr_fault+0x2a2/0x500
  exc_page_fault+0x71/0x90
  asm_exc_page_fault+0x22/0x30

Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/2136178.1721725194@warthog.procyon.org.uk
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christian Brauner <brauner@kernel.org>
cc: Jan Kara <jack@suse.cz>
cc: Jeff Layton <jlayton@kernel.org>
cc: Gao Xiang <xiang@kernel.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: netfs@lists.linux.dev
cc: linux-erofs@lists.ozlabs.org
cc: linux-fsdevel@vger.kernel.org
[brauner: fix minor issues]
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Nov 6, 2024
[ Upstream commit 348a198 ]

Luis has been reporting an assert failure when freeing an inode
cluster during inode inactivation for a while. The assert looks
like:

 XFS: Assertion failed: bp->b_flags & XBF_DONE, file: fs/xfs/xfs_trans_buf.c, line: 241
 ------------[ cut here ]------------
 kernel BUG at fs/xfs/xfs_message.c:102!
 Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
 CPU: 4 PID: 73 Comm: kworker/4:1 Not tainted 6.10.0-rc1 #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
 Workqueue: xfs-inodegc/loop5 xfs_inodegc_worker [xfs]
 RIP: 0010:assfail (fs/xfs/xfs_message.c:102) xfs
 RSP: 0018:ffff88810188f7f0 EFLAGS: 00010202
 RAX: 0000000000000000 RBX: ffff88816e748250 RCX: 1ffffffff844b0e7
 RDX: 0000000000000004 RSI: ffff88810188f558 RDI: ffffffffc2431fa0
 RBP: 1ffff11020311f01 R08: 0000000042431f9f R09: ffffed1020311e9b
 R10: ffff88810188f4df R11: ffffffffac725d70 R12: ffff88817a3f4000
 R13: ffff88812182f000 R14: ffff88810188f998 R15: ffffffffc2423f80
 FS:  0000000000000000(0000) GS:ffff8881c8400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055fe9d0f109c CR3: 000000014426c002 CR4: 0000000000770ef0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
 xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:241 (discriminator 1)) xfs
 xfs_imap_to_bp (fs/xfs/xfs_trans.h:210 fs/xfs/libxfs/xfs_inode_buf.c:138) xfs
 xfs_inode_item_precommit (fs/xfs/xfs_inode_item.c:145) xfs
 xfs_trans_run_precommits (fs/xfs/xfs_trans.c:931) xfs
 __xfs_trans_commit (fs/xfs/xfs_trans.c:966) xfs
 xfs_inactive_ifree (fs/xfs/xfs_inode.c:1811) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:2013) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1841 fs/xfs/xfs_icache.c:1886) xfs
 process_one_work (kernel/workqueue.c:3231)
 worker_thread (kernel/workqueue.c:3306 (discriminator 2) kernel/workqueue.c:3393 (discriminator 2))
 kthread (kernel/kthread.c:389)
 ret_from_fork (arch/x86/kernel/process.c:147)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:257)
  </TASK>

And occurs when the the inode precommit handlers is attempt to look
up the inode cluster buffer to attach the inode for writeback.

The trail of logic that I can reconstruct is as follows.

	1. the inode is clean when inodegc runs, so it is not
	   attached to a cluster buffer when precommit runs.

	2. #1 implies the inode cluster buffer may be clean and not
	   pinned by dirty inodes when inodegc runs.

	3. #2 implies that the inode cluster buffer can be reclaimed
	   by memory pressure at any time.

	4. The assert failure implies that the cluster buffer was
	   attached to the transaction, but not marked done. It had
	   been accessed earlier in the transaction, but not marked
	   done.

	5. #4 implies the cluster buffer has been invalidated (i.e.
	   marked stale).

	6. #5 implies that the inode cluster buffer was instantiated
	   uninitialised in the transaction in xfs_ifree_cluster(),
	   which only instantiates the buffers to invalidate them
	   and never marks them as done.

Given factors 1-3, this issue is highly dependent on timing and
environmental factors. Hence the issue can be very difficult to
reproduce in some situations, but highly reliable in others. Luis
has an environment where it can be reproduced easily by g/531 but,
OTOH, I've reproduced it only once in ~2000 cycles of g/531.

I think the fix is to have xfs_ifree_cluster() set the XBF_DONE flag
on the cluster buffers, even though they may not be initialised. The
reasons why I think this is safe are:

	1. A buffer cache lookup hit on a XBF_STALE buffer will
	   clear the XBF_DONE flag. Hence all future users of the
	   buffer know they have to re-initialise the contents
	   before use and mark it done themselves.

	2. xfs_trans_binval() sets the XFS_BLI_STALE flag, which
	   means the buffer remains locked until the journal commit
	   completes and the buffer is unpinned. Hence once marked
	   XBF_STALE/XFS_BLI_STALE by xfs_ifree_cluster(), the only
	   context that can access the freed buffer is the currently
	   running transaction.

	3. #2 implies that future buffer lookups in the currently
	   running transaction will hit the transaction match code
	   and not the buffer cache. Hence XBF_STALE and
	   XFS_BLI_STALE will not be cleared unless the transaction
	   initialises and logs the buffer with valid contents
	   again. At which point, the buffer will be marked marked
	   XBF_DONE again, so having XBF_DONE already set on the
	   stale buffer is a moot point.

	4. #2 also implies that any concurrent access to that
	   cluster buffer will block waiting on the buffer lock
	   until the inode cluster has been fully freed and is no
	   longer an active inode cluster buffer.

	5. #4 + #1 means that any future user of the disk range of
	   that buffer will always see the range of disk blocks
	   covered by the cluster buffer as not done, and hence must
	   initialise the contents themselves.

	6. Setting XBF_DONE in xfs_ifree_cluster() then means the
	   unlinked inode precommit code will see a XBF_DONE buffer
	   from the transaction match as it expects. It can then
	   attach the stale but newly dirtied inode to the stale
	   but newly dirtied cluster buffer without unexpected
	   failures. The stale buffer will then sail through the
	   journal and do the right thing with the attached stale
	   inode during unpin.

Hence the fix is just one line of extra code. The explanation of
why we have to set XBF_DONE in xfs_ifree_cluster, OTOH, is long and
complex....

Fixes: 82842fe ("xfs: fix AGF vs inode cluster buffer deadlock")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
Acked-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
commit ac01c8c upstream.

AddressSanitizer found a use-after-free bug in the symbol code which
manifested as 'perf top' segfaulting.

  ==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80
  READ of size 1 at 0x60b00c48844b thread T193
      #0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310
      #1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286
      #2 0x5650d8043951 in hists__findnew_entry util/hist.c:614
      #3 0x5650d804568f in __hists__add_entry util/hist.c:754
      #4 0x5650d8045bf9 in hists__add_entry util/hist.c:772
      #5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997
      #6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242
      #7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845
      #8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208
      #9 0x5650d7fdb51b in do_flush util/ordered-events.c:245
      #10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324
      #11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120
      #12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442
      #13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

When updating hist maps it's also necessary to update the hist symbol
reference because the old one gets freed in map__put().

While this bug was probably introduced with 5c24b67 ("perf
tools: Replace map->referenced & maps->removed_maps with map->refcnt"),
the symbol objects were leaked until c087e94 ("perf machine:
Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so
the bug was masked.

Fixes: c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL")
Reported-by: Yunzhao Li <yunzhao@cloudflare.com>
Signed-off-by: Matt Fleming (Cloudflare) <matt@readmodwrite.com>
Cc: Ian Rogers <irogers@google.com>
Cc: kernel-team@cloudflare.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org # v5.13+
Link: https://lore.kernel.org/r/20240815142212.3834625-1-matt@readmodwrite.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
commit 9af2efe upstream.

The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
…tion to perf_sched__replay()

[ Upstream commit c690786 ]

The start_work_mutex and work_done_wait_mutex are used only for the
'perf sched replay'. Put their initialization in perf_sched__replay () to
reduce unnecessary actions in other commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.197 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 14.952 MB perf.data (134165 samples) ]

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 65658 nsecs
  the run test took 999991 nsecs
  the sleep test took 1079324 nsecs
  nr_run_events:        42378
  nr_sleep_events:      43102
  nr_wakeup_events:     31852
  target-less wakeups:  17
  multi-target wakeups: 712
  task      0 (             swapper:         0), nr_events: 10451
  task      1 (             swapper:         1), nr_events: 3
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    717 (     sched-messaging:     74483), nr_events: 152
  task    718 (     sched-messaging:     74484), nr_events: 1944
  task    719 (     sched-messaging:     74485), nr_events: 73
  task    720 (     sched-messaging:     74486), nr_events: 163
  task    721 (     sched-messaging:     74487), nr_events: 942
  task    722 (     sched-messaging:     74488), nr_events: 78
  task    723 (     sched-messaging:     74489), nr_events: 1090
  ------------------------------------------------------------
  #1  : 1366.507, ravg: 1366.51, cpu: 7682.70 / 7682.70
  #2  : 1410.072, ravg: 1370.86, cpu: 7723.88 / 7686.82
  #3  : 1396.296, ravg: 1373.41, cpu: 7568.20 / 7674.96
  #4  : 1381.019, ravg: 1374.17, cpu: 7531.81 / 7660.64
  #5  : 1393.826, ravg: 1376.13, cpu: 7725.25 / 7667.11
  #6  : 1401.581, ravg: 1378.68, cpu: 7594.82 / 7659.88
  #7  : 1381.337, ravg: 1378.94, cpu: 7371.22 / 7631.01
  #8  : 1373.842, ravg: 1378.43, cpu: 7894.92 / 7657.40
  #9  : 1364.697, ravg: 1377.06, cpu: 7324.91 / 7624.15
  #10 : 1363.613, ravg: 1375.72, cpu: 7209.55 / 7582.69
  # echo $?
  0

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206083228.172607-2-yangjihong1@huawei.com
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
…f_sched__{lat|map|replay}()

[ Upstream commit bd2cdf2 ]

The curr_pid and cpu_last_switched are used only for the
'perf sched replay/latency/map'. Put their initialization in
perf_sched__{lat|map|replay () to reduce unnecessary actions in other
commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.209 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 16.456 MB perf.data (147907 samples) ]

  # perf sched lat

   -------------------------------------------------------------------------------------------------------------------------------------------
    Task                  |   Runtime ms  | Switches | Avg delay ms    | Max delay ms    | Max delay start           | Max delay end          |
   -------------------------------------------------------------------------------------------------------------------------------------------
    sched-messaging:(401) |   2990.699 ms |    38705 | avg:   0.661 ms | max:  67.046 ms | max start: 456532.624830 s | max end: 456532.691876 s
    qemu-system-x86:(7)   |    179.764 ms |     2191 | avg:   0.152 ms | max:  21.857 ms | max start: 456532.576434 s | max end: 456532.598291 s
    sshd:48125            |      0.522 ms |        2 | avg:   0.037 ms | max:   0.046 ms | max start: 456532.514610 s | max end: 456532.514656 s
  <SNIP>
    ksoftirqd/11:82       |      0.063 ms |        1 | avg:   0.005 ms | max:   0.005 ms | max start: 456532.769366 s | max end: 456532.769371 s
    kworker/9:0-mm_:34624 |      0.233 ms |       20 | avg:   0.004 ms | max:   0.007 ms | max start: 456532.690804 s | max end: 456532.690812 s
    migration/13:93       |      0.000 ms |        1 | avg:   0.004 ms | max:   0.004 ms | max start: 456532.512669 s | max end: 456532.512674 s
   -----------------------------------------------------------------------------------------------------------------
    TOTAL:                |   3180.750 ms |    41368 |
   ---------------------------------------------------

  # echo $?
  0

  # perf sched map
    *A0                                                               456532.510141 secs A0 => migration/0:15
    *.                                                                456532.510171 secs .  => swapper:0
     .  *B0                                                           456532.510261 secs B0 => migration/1:21
     .  *.                                                            456532.510279 secs
  <SNIP>
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .   .    456532.785979 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .    456532.786054 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .    456532.786127 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .    456532.786197 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7   456532.786270 secs
  # echo $?
  0

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 66473 nsecs
  the run test took 1000002 nsecs
  the sleep test took 1082686 nsecs
  nr_run_events:        49334
  nr_sleep_events:      50054
  nr_wakeup_events:     34701
  target-less wakeups:  165
  multi-target wakeups: 766
  task      0 (             swapper:         0), nr_events: 15419
  task      1 (             swapper:         1), nr_events: 1
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    715 (     sched-messaging:    110248), nr_events: 1438
  task    716 (     sched-messaging:    110249), nr_events: 512
  task    717 (     sched-messaging:    110250), nr_events: 500
  task    718 (     sched-messaging:    110251), nr_events: 537
  task    719 (     sched-messaging:    110252), nr_events: 823
  ------------------------------------------------------------
  #1  : 1325.288, ravg: 1325.29, cpu: 7823.35 / 7823.35
  #2  : 1363.606, ravg: 1329.12, cpu: 7655.53 / 7806.56
  #3  : 1349.494, ravg: 1331.16, cpu: 7544.80 / 7780.39
  #4  : 1311.488, ravg: 1329.19, cpu: 7495.13 / 7751.86
  #5  : 1309.902, ravg: 1327.26, cpu: 7266.65 / 7703.34
  #6  : 1309.535, ravg: 1325.49, cpu: 7843.86 / 7717.39
  #7  : 1316.482, ravg: 1324.59, cpu: 7854.41 / 7731.09
  #8  : 1366.604, ravg: 1328.79, cpu: 7955.81 / 7753.57
  #9  : 1326.286, ravg: 1328.54, cpu: 7466.86 / 7724.90
  #10 : 1356.653, ravg: 1331.35, cpu: 7566.60 / 7709.07
  # echo $?
  0

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206083228.172607-5-yangjihong1@huawei.com
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
[ Upstream commit d1bc560 ]

Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning
while handling xattr inode on file open syscall at ext4_xattr_inode_iget.

Backtrace
EXT4-fs (loop0): Ignoring removed oldalloc option
======================================================
WARNING: possible circular locking dependency detected
5.10.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor543/2794 is trying to acquire lock:
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425

but task is already holding lock:
ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline]
       ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline]
       ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662
       ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228
       ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385
       ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498
       ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40
       __vfs_setxattr+0x404/0x450 fs/xattr.c:177
       __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208
       __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266
       vfs_setxattr+0x112/0x2c0 fs/xattr.c:283
       setxattr+0x1db/0x3e0 fs/xattr.c:548
       path_setxattr+0x15a/0x240 fs/xattr.c:567
       __do_sys_setxattr fs/xattr.c:582 [inline]
       __se_sys_setxattr fs/xattr.c:578 [inline]
       __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2988 [inline]
       check_prevs_add kernel/locking/lockdep.c:3113 [inline]
       validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
       __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       inode_lock include/linux/fs.h:782 [inline]
       ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
       ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
       ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
       ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
       __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
       __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
       ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
       notify_change+0xbb6/0xe60 fs/attr.c:435
       do_truncate+0x1de/0x2c0 fs/open.c:64
       handle_truncate fs/namei.c:2970 [inline]
       do_open fs/namei.c:3311 [inline]
       path_openat+0x29f3/0x3290 fs/namei.c:3425
       do_filp_open+0x20b/0x450 fs/namei.c:3452
       do_sys_openat2+0x124/0x460 fs/open.c:1207
       do_sys_open fs/open.c:1223 [inline]
       __do_sys_open fs/open.c:1231 [inline]
       __se_sys_open fs/open.c:1227 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1227
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/3);
                               lock(&ea_inode->i_rwsem#7/1);
                               lock(&ei->i_data_sem/3);
  lock(&ea_inode->i_rwsem#7/1);

 *** DEADLOCK ***

5 locks held by syz-executor543/2794:
 #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62
 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519
 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018

stack backtrace:
CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x177/0x211 lib/dump_stack.c:118
 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123
 check_prev_add kernel/locking/lockdep.c:2988 [inline]
 check_prevs_add kernel/locking/lockdep.c:3113 [inline]
 validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
 down_write+0x93/0x180 kernel/locking/rwsem.c:1564
 inode_lock include/linux/fs.h:782 [inline]
 ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
 ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
 __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
 notify_change+0xbb6/0xe60 fs/attr.c:435
 do_truncate+0x1de/0x2c0 fs/open.c:64
 handle_truncate fs/namei.c:2970 [inline]
 do_open fs/namei.c:3311 [inline]
 path_openat+0x29f3/0x3290 fs/namei.c:3425
 do_filp_open+0x20b/0x450 fs/namei.c:3452
 do_sys_openat2+0x124/0x460 fs/open.c:1207
 do_sys_open fs/open.c:1223 [inline]
 __do_sys_open fs/open.c:1231 [inline]
 __se_sys_open fs/open.c:1227 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1227
 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0cde4ea229
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229
RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0
RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0
R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003
EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode #13: comm syz-executor543: corrupted in-inode xattr

Signed-off-by: Wojciech Gładysz <wojciech.gladysz@infogain.com>
Link: https://patch.msgid.link/20240801143827.19135-1-wojciech.gladysz@infogain.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
[ Upstream commit a848c29 ]

On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <zhangyanjun@cestc.cn>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
commit abaf1e0 upstream.

While debugging a segfault on 'perf lock contention' without an
available perf.data file I noticed that it was basically calling:

	perf_session__delete(ERR_PTR(-1))

Resulting in:

  (gdb) run lock contention
  Starting program: /root/bin/perf lock contention
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib64/libthread_db.so.1".
  failed to open perf.data: No such file or directory  (try 'perf record' first)
  Initializing perf session failed

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  2858		if (!session->auxtrace)
  (gdb) p session
  $1 = (struct perf_session *) 0xffffffffffffffff
  (gdb) bt
  #0  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  #1  0x000000000057bb4d in perf_session__delete (session=0xffffffffffffffff) at util/session.c:300
  #2  0x000000000047c421 in __cmd_contention (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2161
  #3  0x000000000047dc95 in cmd_lock (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2604
  #4  0x0000000000501466 in run_builtin (p=0xe597a8 <commands+552>, argc=2, argv=0x7fffffffe200) at perf.c:322
  #5  0x00000000005016d5 in handle_internal_command (argc=2, argv=0x7fffffffe200) at perf.c:375
  #6  0x0000000000501824 in run_argv (argcp=0x7fffffffe02c, argv=0x7fffffffe020) at perf.c:419
  #7  0x0000000000501b11 in main (argc=2, argv=0x7fffffffe200) at perf.c:535
  (gdb)

So just set it to NULL after using PTR_ERR(session) to decode the error
as perf_session__delete(NULL) is supported.

Fixes: eef4fee ("perf lock: Dynamically allocate lockhash_table")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/lkml/ZN4R1AYfsD2J8lRs@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
commit 3d04139 upstream.

Syzkaller reported a lockdep splat:

  ============================================
  WARNING: possible recursive locking detected
  6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
  --------------------------------------------
  syz-executor364/5113 is trying to acquire lock:
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  but task is already holding lock:
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(k-slock-AF_INET);
    lock(k-slock-AF_INET);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  7 locks held by syz-executor364/5113:
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  stack backtrace:
  CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:93 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
   check_deadlock kernel/locking/lockdep.c:3061 [inline]
   validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
   __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
   mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
   subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
   tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
   tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
   ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6108
   __napi_poll+0xcb/0x490 net/core/dev.c:6772
   napi_poll net/core/dev.c:6841 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6963
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   do_softirq+0x11b/0x1e0 kernel/softirq.c:455
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
   __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
   neigh_hh_output include/net/neighbour.h:526 [inline]
   neigh_output include/net/neighbour.h:540 [inline]
   ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
   ip_local_out net/ipv4/ip_output.c:129 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
   tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
   tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3004
   release_sock+0x61/0x1f0 net/core/sock.c:3558
   mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
   ___sys_sendmsg net/socket.c:2651 [inline]
   __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
   __do_sys_sendmmsg net/socket.c:2766 [inline]
   __se_sys_sendmmsg net/socket.c:2763 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f04fb13a6b9
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
  RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
  RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
  R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
   </TASK>

As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.

Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.

Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.

Fixes: 1729cf1 ("mptcp: create the listening socket for new port")
Cc: stable@vger.kernel.org
Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241014-net-mptcp-mpc-port-endp-v2-1-7faea8e6b6ae@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in mib.[ch], because commit 6982826 ("mptcp: fallback
  to TCP after SYN+MPC drops"), and commit 27069e7 ("mptcp: disable
  active MPTCP in case of blackhole") are linked to new features, not
  available in this version. Resolving the conflicts is easy, simply
  adding the new lines declaring the new "endpoint attempt" MIB entry.
  Also a conflict in protocol.h, because commit fce68b0 ("mptcp:
  add scheduled in mptcp_subflow_context") is not in this version, and
  changes the context by introducing 'scheduled' variable just before.
  Also a conflict in pm_netlink.c, because commit 3aa3624 ("mptcp:
  avoid ssock usage in mptcp_pm_nl_create_listen_socket()") is not in
  this version, and refactor the function: that's fine, we can still set
  pm_listener before doing the 'listen()', taking 'ssock->sk' as 'ssk'
  is not defined before this refactoring. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 6, 2024
commit 78cfd17 upstream.

Undefined behavior is triggered when bnxt_qplib_alloc_init_hwq is called
with hwq_attr->aux_depth != 0 and hwq_attr->aux_stride == 0.
In that case, "roundup_pow_of_two(hwq_attr->aux_stride)" gets called.
roundup_pow_of_two is documented as undefined for 0.

Fix it in the one caller that had this combination.

The undefined behavior was detected by UBSAN:
  UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
  shift exponent 64 is too large for 64-bit type 'long unsigned int'
  CPU: 24 PID: 1075 Comm: (udev-worker) Not tainted 6.9.0-rc6+ #4
  Hardware name: Abacus electric, s.r.o. - servis@abacus.cz Super Server/H12SSW-iN, BIOS 2.7 10/25/2023
  Call Trace:
   <TASK>
   dump_stack_lvl+0x5d/0x80
   ubsan_epilogue+0x5/0x30
   __ubsan_handle_shift_out_of_bounds.cold+0x61/0xec
   __roundup_pow_of_two+0x25/0x35 [bnxt_re]
   bnxt_qplib_alloc_init_hwq+0xa1/0x470 [bnxt_re]
   bnxt_qplib_create_qp+0x19e/0x840 [bnxt_re]
   bnxt_re_create_qp+0x9b1/0xcd0 [bnxt_re]
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __kmalloc+0x1b6/0x4f0
   ? create_qp.part.0+0x128/0x1c0 [ib_core]
   ? __pfx_bnxt_re_create_qp+0x10/0x10 [bnxt_re]
   create_qp.part.0+0x128/0x1c0 [ib_core]
   ib_create_qp_kernel+0x50/0xd0 [ib_core]
   create_mad_qp+0x8e/0xe0 [ib_core]
   ? __pfx_qp_event_handler+0x10/0x10 [ib_core]
   ib_mad_init_device+0x2be/0x680 [ib_core]
   add_client_context+0x10d/0x1a0 [ib_core]
   enable_device_and_get+0xe0/0x1d0 [ib_core]
   ib_register_device+0x53c/0x630 [ib_core]
   ? srso_alias_return_thunk+0x5/0xfbef5
   bnxt_re_probe+0xbd8/0xe50 [bnxt_re]
   ? __pfx_bnxt_re_probe+0x10/0x10 [bnxt_re]
   auxiliary_bus_probe+0x49/0x80
   ? driver_sysfs_add+0x57/0xc0
   really_probe+0xde/0x340
   ? pm_runtime_barrier+0x54/0x90
   ? __pfx___driver_attach+0x10/0x10
   __driver_probe_device+0x78/0x110
   driver_probe_device+0x1f/0xa0
   __driver_attach+0xba/0x1c0
   bus_for_each_dev+0x8f/0xe0
   bus_add_driver+0x146/0x220
   driver_register+0x72/0xd0
   __auxiliary_driver_register+0x6e/0xd0
   ? __pfx_bnxt_re_mod_init+0x10/0x10 [bnxt_re]
   bnxt_re_mod_init+0x3e/0xff0 [bnxt_re]
   ? __pfx_bnxt_re_mod_init+0x10/0x10 [bnxt_re]
   do_one_initcall+0x5b/0x310
   do_init_module+0x90/0x250
   init_module_from_file+0x86/0xc0
   idempotent_init_module+0x121/0x2b0
   __x64_sys_finit_module+0x5e/0xb0
   do_syscall_64+0x82/0x160
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? syscall_exit_to_user_mode_prepare+0x149/0x170
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? syscall_exit_to_user_mode+0x75/0x230
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? do_syscall_64+0x8e/0x160
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __count_memcg_events+0x69/0x100
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? count_memcg_events.constprop.0+0x1a/0x30
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? handle_mm_fault+0x1f0/0x300
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? do_user_addr_fault+0x34e/0x640
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4e5132821d
  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 db 0c 00 f7 d8 64 89 01 48
  RSP: 002b:00007ffca9c906a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
  RAX: ffffffffffffffda RBX: 0000563ec8a8f130 RCX: 00007f4e5132821d
  RDX: 0000000000000000 RSI: 00007f4e518fa07d RDI: 000000000000003b
  RBP: 00007ffca9c90760 R08: 00007f4e513f6b20 R09: 00007ffca9c906f0
  R10: 0000563ec8a8faa0 R11: 0000000000000246 R12: 00007f4e518fa07d
  R13: 0000000000020000 R14: 0000563ec8409e90 R15: 0000563ec8a8fa60
   </TASK>
  ---[ end trace ]---

Fixes: 0c4dcd6 ("RDMA/bnxt_re: Refactor hardware queue memory allocation")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Link: https://lore.kernel.org/r/20240507103929.30003-1-mschmidt@redhat.com
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
commit 9af2efe upstream.

The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
…tion to perf_sched__replay()

[ Upstream commit c690786 ]

The start_work_mutex and work_done_wait_mutex are used only for the
'perf sched replay'. Put their initialization in perf_sched__replay () to
reduce unnecessary actions in other commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.197 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 14.952 MB perf.data (134165 samples) ]

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 65658 nsecs
  the run test took 999991 nsecs
  the sleep test took 1079324 nsecs
  nr_run_events:        42378
  nr_sleep_events:      43102
  nr_wakeup_events:     31852
  target-less wakeups:  17
  multi-target wakeups: 712
  task      0 (             swapper:         0), nr_events: 10451
  task      1 (             swapper:         1), nr_events: 3
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    717 (     sched-messaging:     74483), nr_events: 152
  task    718 (     sched-messaging:     74484), nr_events: 1944
  task    719 (     sched-messaging:     74485), nr_events: 73
  task    720 (     sched-messaging:     74486), nr_events: 163
  task    721 (     sched-messaging:     74487), nr_events: 942
  task    722 (     sched-messaging:     74488), nr_events: 78
  task    723 (     sched-messaging:     74489), nr_events: 1090
  ------------------------------------------------------------
  #1  : 1366.507, ravg: 1366.51, cpu: 7682.70 / 7682.70
  #2  : 1410.072, ravg: 1370.86, cpu: 7723.88 / 7686.82
  #3  : 1396.296, ravg: 1373.41, cpu: 7568.20 / 7674.96
  #4  : 1381.019, ravg: 1374.17, cpu: 7531.81 / 7660.64
  #5  : 1393.826, ravg: 1376.13, cpu: 7725.25 / 7667.11
  #6  : 1401.581, ravg: 1378.68, cpu: 7594.82 / 7659.88
  #7  : 1381.337, ravg: 1378.94, cpu: 7371.22 / 7631.01
  #8  : 1373.842, ravg: 1378.43, cpu: 7894.92 / 7657.40
  #9  : 1364.697, ravg: 1377.06, cpu: 7324.91 / 7624.15
  #10 : 1363.613, ravg: 1375.72, cpu: 7209.55 / 7582.69
  # echo $?
  0

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206083228.172607-2-yangjihong1@huawei.com
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
…f_sched__{lat|map|replay}()

[ Upstream commit bd2cdf2 ]

The curr_pid and cpu_last_switched are used only for the
'perf sched replay/latency/map'. Put their initialization in
perf_sched__{lat|map|replay () to reduce unnecessary actions in other
commands.

Simple functional testing:

  # perf sched record perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.209 [sec]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 16.456 MB perf.data (147907 samples) ]

  # perf sched lat

   -------------------------------------------------------------------------------------------------------------------------------------------
    Task                  |   Runtime ms  | Switches | Avg delay ms    | Max delay ms    | Max delay start           | Max delay end          |
   -------------------------------------------------------------------------------------------------------------------------------------------
    sched-messaging:(401) |   2990.699 ms |    38705 | avg:   0.661 ms | max:  67.046 ms | max start: 456532.624830 s | max end: 456532.691876 s
    qemu-system-x86:(7)   |    179.764 ms |     2191 | avg:   0.152 ms | max:  21.857 ms | max start: 456532.576434 s | max end: 456532.598291 s
    sshd:48125            |      0.522 ms |        2 | avg:   0.037 ms | max:   0.046 ms | max start: 456532.514610 s | max end: 456532.514656 s
  <SNIP>
    ksoftirqd/11:82       |      0.063 ms |        1 | avg:   0.005 ms | max:   0.005 ms | max start: 456532.769366 s | max end: 456532.769371 s
    kworker/9:0-mm_:34624 |      0.233 ms |       20 | avg:   0.004 ms | max:   0.007 ms | max start: 456532.690804 s | max end: 456532.690812 s
    migration/13:93       |      0.000 ms |        1 | avg:   0.004 ms | max:   0.004 ms | max start: 456532.512669 s | max end: 456532.512674 s
   -----------------------------------------------------------------------------------------------------------------
    TOTAL:                |   3180.750 ms |    41368 |
   ---------------------------------------------------

  # echo $?
  0

  # perf sched map
    *A0                                                               456532.510141 secs A0 => migration/0:15
    *.                                                                456532.510171 secs .  => swapper:0
     .  *B0                                                           456532.510261 secs B0 => migration/1:21
     .  *.                                                            456532.510279 secs
  <SNIP>
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .   .    456532.785979 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .   .    456532.786054 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .   .    456532.786127 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7  .    456532.786197 secs
     L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7  L7 *L7   456532.786270 secs
  # echo $?
  0

  # perf sched replay
  run measurement overhead: 108 nsecs
  sleep measurement overhead: 66473 nsecs
  the run test took 1000002 nsecs
  the sleep test took 1082686 nsecs
  nr_run_events:        49334
  nr_sleep_events:      50054
  nr_wakeup_events:     34701
  target-less wakeups:  165
  multi-target wakeups: 766
  task      0 (             swapper:         0), nr_events: 15419
  task      1 (             swapper:         1), nr_events: 1
  task      2 (             swapper:         2), nr_events: 1
  <SNIP>
  task    715 (     sched-messaging:    110248), nr_events: 1438
  task    716 (     sched-messaging:    110249), nr_events: 512
  task    717 (     sched-messaging:    110250), nr_events: 500
  task    718 (     sched-messaging:    110251), nr_events: 537
  task    719 (     sched-messaging:    110252), nr_events: 823
  ------------------------------------------------------------
  #1  : 1325.288, ravg: 1325.29, cpu: 7823.35 / 7823.35
  #2  : 1363.606, ravg: 1329.12, cpu: 7655.53 / 7806.56
  #3  : 1349.494, ravg: 1331.16, cpu: 7544.80 / 7780.39
  #4  : 1311.488, ravg: 1329.19, cpu: 7495.13 / 7751.86
  #5  : 1309.902, ravg: 1327.26, cpu: 7266.65 / 7703.34
  #6  : 1309.535, ravg: 1325.49, cpu: 7843.86 / 7717.39
  #7  : 1316.482, ravg: 1324.59, cpu: 7854.41 / 7731.09
  #8  : 1366.604, ravg: 1328.79, cpu: 7955.81 / 7753.57
  #9  : 1326.286, ravg: 1328.54, cpu: 7466.86 / 7724.90
  #10 : 1356.653, ravg: 1331.35, cpu: 7566.60 / 7709.07
  # echo $?
  0

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206083228.172607-5-yangjihong1@huawei.com
Stable-dep-of: 1a5efc9 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
[ Upstream commit d1bc560 ]

Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning
while handling xattr inode on file open syscall at ext4_xattr_inode_iget.

Backtrace
EXT4-fs (loop0): Ignoring removed oldalloc option
======================================================
WARNING: possible circular locking dependency detected
5.10.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor543/2794 is trying to acquire lock:
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425

but task is already holding lock:
ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline]
       ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline]
       ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662
       ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228
       ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385
       ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498
       ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40
       __vfs_setxattr+0x404/0x450 fs/xattr.c:177
       __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208
       __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266
       vfs_setxattr+0x112/0x2c0 fs/xattr.c:283
       setxattr+0x1db/0x3e0 fs/xattr.c:548
       path_setxattr+0x15a/0x240 fs/xattr.c:567
       __do_sys_setxattr fs/xattr.c:582 [inline]
       __se_sys_setxattr fs/xattr.c:578 [inline]
       __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2988 [inline]
       check_prevs_add kernel/locking/lockdep.c:3113 [inline]
       validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
       __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       inode_lock include/linux/fs.h:782 [inline]
       ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
       ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
       ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
       ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
       __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
       __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
       ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
       notify_change+0xbb6/0xe60 fs/attr.c:435
       do_truncate+0x1de/0x2c0 fs/open.c:64
       handle_truncate fs/namei.c:2970 [inline]
       do_open fs/namei.c:3311 [inline]
       path_openat+0x29f3/0x3290 fs/namei.c:3425
       do_filp_open+0x20b/0x450 fs/namei.c:3452
       do_sys_openat2+0x124/0x460 fs/open.c:1207
       do_sys_open fs/open.c:1223 [inline]
       __do_sys_open fs/open.c:1231 [inline]
       __se_sys_open fs/open.c:1227 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1227
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/3);
                               lock(&ea_inode->i_rwsem#7/1);
                               lock(&ei->i_data_sem/3);
  lock(&ea_inode->i_rwsem#7/1);

 *** DEADLOCK ***

5 locks held by syz-executor543/2794:
 #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62
 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519
 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018

stack backtrace:
CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x177/0x211 lib/dump_stack.c:118
 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123
 check_prev_add kernel/locking/lockdep.c:2988 [inline]
 check_prevs_add kernel/locking/lockdep.c:3113 [inline]
 validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
 down_write+0x93/0x180 kernel/locking/rwsem.c:1564
 inode_lock include/linux/fs.h:782 [inline]
 ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
 ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
 __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
 notify_change+0xbb6/0xe60 fs/attr.c:435
 do_truncate+0x1de/0x2c0 fs/open.c:64
 handle_truncate fs/namei.c:2970 [inline]
 do_open fs/namei.c:3311 [inline]
 path_openat+0x29f3/0x3290 fs/namei.c:3425
 do_filp_open+0x20b/0x450 fs/namei.c:3452
 do_sys_openat2+0x124/0x460 fs/open.c:1207
 do_sys_open fs/open.c:1223 [inline]
 __do_sys_open fs/open.c:1231 [inline]
 __se_sys_open fs/open.c:1227 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1227
 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0cde4ea229
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229
RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0
RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0
R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003
EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode #13: comm syz-executor543: corrupted in-inode xattr

Signed-off-by: Wojciech Gładysz <wojciech.gladysz@infogain.com>
Link: https://patch.msgid.link/20240801143827.19135-1-wojciech.gladysz@infogain.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
[ Upstream commit a848c29 ]

On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <zhangyanjun@cestc.cn>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
commit 348a198 upstream.

Luis has been reporting an assert failure when freeing an inode
cluster during inode inactivation for a while. The assert looks
like:

 XFS: Assertion failed: bp->b_flags & XBF_DONE, file: fs/xfs/xfs_trans_buf.c, line: 241
 ------------[ cut here ]------------
 kernel BUG at fs/xfs/xfs_message.c:102!
 Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
 CPU: 4 PID: 73 Comm: kworker/4:1 Not tainted 6.10.0-rc1 #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
 Workqueue: xfs-inodegc/loop5 xfs_inodegc_worker [xfs]
 RIP: 0010:assfail (fs/xfs/xfs_message.c:102) xfs
 RSP: 0018:ffff88810188f7f0 EFLAGS: 00010202
 RAX: 0000000000000000 RBX: ffff88816e748250 RCX: 1ffffffff844b0e7
 RDX: 0000000000000004 RSI: ffff88810188f558 RDI: ffffffffc2431fa0
 RBP: 1ffff11020311f01 R08: 0000000042431f9f R09: ffffed1020311e9b
 R10: ffff88810188f4df R11: ffffffffac725d70 R12: ffff88817a3f4000
 R13: ffff88812182f000 R14: ffff88810188f998 R15: ffffffffc2423f80
 FS:  0000000000000000(0000) GS:ffff8881c8400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055fe9d0f109c CR3: 000000014426c002 CR4: 0000000000770ef0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
 xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:241 (discriminator 1)) xfs
 xfs_imap_to_bp (fs/xfs/xfs_trans.h:210 fs/xfs/libxfs/xfs_inode_buf.c:138) xfs
 xfs_inode_item_precommit (fs/xfs/xfs_inode_item.c:145) xfs
 xfs_trans_run_precommits (fs/xfs/xfs_trans.c:931) xfs
 __xfs_trans_commit (fs/xfs/xfs_trans.c:966) xfs
 xfs_inactive_ifree (fs/xfs/xfs_inode.c:1811) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:2013) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1841 fs/xfs/xfs_icache.c:1886) xfs
 process_one_work (kernel/workqueue.c:3231)
 worker_thread (kernel/workqueue.c:3306 (discriminator 2) kernel/workqueue.c:3393 (discriminator 2))
 kthread (kernel/kthread.c:389)
 ret_from_fork (arch/x86/kernel/process.c:147)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:257)
  </TASK>

And occurs when the the inode precommit handlers is attempt to look
up the inode cluster buffer to attach the inode for writeback.

The trail of logic that I can reconstruct is as follows.

	1. the inode is clean when inodegc runs, so it is not
	   attached to a cluster buffer when precommit runs.

	2. #1 implies the inode cluster buffer may be clean and not
	   pinned by dirty inodes when inodegc runs.

	3. #2 implies that the inode cluster buffer can be reclaimed
	   by memory pressure at any time.

	4. The assert failure implies that the cluster buffer was
	   attached to the transaction, but not marked done. It had
	   been accessed earlier in the transaction, but not marked
	   done.

	5. #4 implies the cluster buffer has been invalidated (i.e.
	   marked stale).

	6. #5 implies that the inode cluster buffer was instantiated
	   uninitialised in the transaction in xfs_ifree_cluster(),
	   which only instantiates the buffers to invalidate them
	   and never marks them as done.

Given factors 1-3, this issue is highly dependent on timing and
environmental factors. Hence the issue can be very difficult to
reproduce in some situations, but highly reliable in others. Luis
has an environment where it can be reproduced easily by g/531 but,
OTOH, I've reproduced it only once in ~2000 cycles of g/531.

I think the fix is to have xfs_ifree_cluster() set the XBF_DONE flag
on the cluster buffers, even though they may not be initialised. The
reasons why I think this is safe are:

	1. A buffer cache lookup hit on a XBF_STALE buffer will
	   clear the XBF_DONE flag. Hence all future users of the
	   buffer know they have to re-initialise the contents
	   before use and mark it done themselves.

	2. xfs_trans_binval() sets the XFS_BLI_STALE flag, which
	   means the buffer remains locked until the journal commit
	   completes and the buffer is unpinned. Hence once marked
	   XBF_STALE/XFS_BLI_STALE by xfs_ifree_cluster(), the only
	   context that can access the freed buffer is the currently
	   running transaction.

	3. #2 implies that future buffer lookups in the currently
	   running transaction will hit the transaction match code
	   and not the buffer cache. Hence XBF_STALE and
	   XFS_BLI_STALE will not be cleared unless the transaction
	   initialises and logs the buffer with valid contents
	   again. At which point, the buffer will be marked marked
	   XBF_DONE again, so having XBF_DONE already set on the
	   stale buffer is a moot point.

	4. #2 also implies that any concurrent access to that
	   cluster buffer will block waiting on the buffer lock
	   until the inode cluster has been fully freed and is no
	   longer an active inode cluster buffer.

	5. #4 + #1 means that any future user of the disk range of
	   that buffer will always see the range of disk blocks
	   covered by the cluster buffer as not done, and hence must
	   initialise the contents themselves.

	6. Setting XBF_DONE in xfs_ifree_cluster() then means the
	   unlinked inode precommit code will see a XBF_DONE buffer
	   from the transaction match as it expects. It can then
	   attach the stale but newly dirtied inode to the stale
	   but newly dirtied cluster buffer without unexpected
	   failures. The stale buffer will then sail through the
	   journal and do the right thing with the attached stale
	   inode during unpin.

Hence the fix is just one line of extra code. The explanation of
why we have to set XBF_DONE in xfs_ifree_cluster, OTOH, is long and
complex....

Fixes: 82842fe ("xfs: fix AGF vs inode cluster buffer deadlock")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: Catherine Hoang <catherine.hoang@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Dec 10, 2024
commit 3d04139 upstream.

Syzkaller reported a lockdep splat:

  ============================================
  WARNING: possible recursive locking detected
  6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
  --------------------------------------------
  syz-executor364/5113 is trying to acquire lock:
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  but task is already holding lock:
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(k-slock-AF_INET);
    lock(k-slock-AF_INET);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  7 locks held by syz-executor364/5113:
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
   #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
   #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  stack backtrace:
  CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:93 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
   check_deadlock kernel/locking/lockdep.c:3061 [inline]
   validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
   __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
   mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
   subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
   tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
   tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
   ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6108
   __napi_poll+0xcb/0x490 net/core/dev.c:6772
   napi_poll net/core/dev.c:6841 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6963
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   do_softirq+0x11b/0x1e0 kernel/softirq.c:455
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
   __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
   neigh_hh_output include/net/neighbour.h:526 [inline]
   neigh_output include/net/neighbour.h:540 [inline]
   ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
   ip_local_out net/ipv4/ip_output.c:129 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
   tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
   tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3004
   release_sock+0x61/0x1f0 net/core/sock.c:3558
   mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
   ___sys_sendmsg net/socket.c:2651 [inline]
   __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
   __do_sys_sendmmsg net/socket.c:2766 [inline]
   __se_sys_sendmmsg net/socket.c:2763 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f04fb13a6b9
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
  RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
  RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
  R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
   </TASK>

As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.

Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.

Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.

Fixes: 1729cf1 ("mptcp: create the listening socket for new port")
Cc: stable@vger.kernel.org
Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241014-net-mptcp-mpc-port-endp-v2-1-7faea8e6b6ae@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in mib.[ch], because commit 6982826 ("mptcp: fallback
  to TCP after SYN+MPC drops"), and commit 27069e7 ("mptcp: disable
  active MPTCP in case of blackhole") are linked to new features, not
  available in this version. Resolving the conflicts is easy, simply
  adding the new lines declaring the new "endpoint attempt" MIB entry. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usercw88 pushed a commit to usercw88/linux that referenced this pull request Feb 4, 2025
[ Upstream commit fd7b4f9 ]

When CONFIG_KASAN_SW_TAGS and CONFIG_KASAN_STACK are enabled, the
object_is_on_stack() function may produce incorrect results due to the
presence of tags in the obj pointer, while the stack pointer does not have
tags.  This discrepancy can lead to incorrect stack object detection and
subsequently trigger warnings if CONFIG_DEBUG_OBJECTS is also enabled.

Example of the warning:

ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:557 __debug_object_init+0x330/0x364
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5 ni#4
Hardware name: linux,dummy-virt (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __debug_object_init+0x330/0x364
lr : __debug_object_init+0x330/0x364
sp : ffff800082ea7b40
x29: ffff800082ea7b40 x28: 98ff0000c0164518 x27: 98ff0000c0164534
x26: ffff800082d93ec8 x25: 0000000000000001 x24: 1cff0000c00172a0
x23: 0000000000000000 x22: ffff800082d93ed0 x21: ffff800081a24418
x20: 3eff800082ea7bb0 x19: efff800000000000 x18: 0000000000000000
x17: 00000000000000ff x16: 0000000000000047 x15: 206b63617473206e
x14: 0000000000000018 x13: ffff800082ea7780 x12: 0ffff800082ea78e
x11: 0ffff800082ea790 x10: 0ffff800082ea79d x9 : 34d77febe173e800
x8 : 34d77febe173e800 x7 : 0000000000000001 x6 : 0000000000000001
x5 : feff800082ea74b8 x4 : ffff800082870a90 x3 : ffff80008018d3c4
x2 : 0000000000000001 x1 : ffff800082858810 x0 : 0000000000000050
Call trace:
 __debug_object_init+0x330/0x364
 debug_object_init_on_stack+0x30/0x3c
 schedule_hrtimeout_range_clock+0xac/0x26c
 schedule_hrtimeout+0x1c/0x30
 wait_task_inactive+0x1d4/0x25c
 kthread_bind_mask+0x28/0x98
 init_rescuer+0x1e8/0x280
 workqueue_init+0x1a0/0x3cc
 kernel_init_freeable+0x118/0x200
 kernel_init+0x28/0x1f0
 ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------

Link: https://lkml.kernel.org/r/20241113042544.19095-1-qun-wei.lin@mediatek.com
Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Cc: Andrew Yang <andrew.yang@mediatek.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Casper Li <casper.li@mediatek.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Resolve line conflicts ]
Signed-off-by: Wenshan Lan <jetlan9@163.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
usercw88 pushed a commit to usercw88/linux that referenced this pull request Feb 4, 2025
…nt message

commit cddc76b upstream.

Address a bug in the kernel that triggers a "sleeping function called from
invalid context" warning when /sys/kernel/debug/kmemleak is printed under
specific conditions:
- CONFIG_PREEMPT_RT=y
- Set SELinux as the LSM for the system
- Set kptr_restrict to 1
- kmemleak buffer contains at least one item

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 136, name: cat
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
6 locks held by cat/136:
 #0: ffff32e64bcbf950 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb8/0xe30
 ni#1: ffffafe6aaa9dea0 (scan_mutex){+.+.}-{3:3}, at: kmemleak_seq_start+0x34/0x128
 ni#3: ffff32e6546b1cd0 (&object->lock){....}-{2:2}, at: kmemleak_seq_show+0x3c/0x1e0
 ni#4: ffffafe6aa8d8560 (rcu_read_lock){....}-{1:2}, at: has_ns_capability_noaudit+0x8/0x1b0
 ni#5: ffffafe6aabbc0f8 (notif_lock){+.+.}-{2:2}, at: avc_compute_av+0xc4/0x3d0
irq event stamp: 136660
hardirqs last  enabled at (136659): [<ffffafe6a80fd7a0>] _raw_spin_unlock_irqrestore+0xa8/0xd8
hardirqs last disabled at (136660): [<ffffafe6a80fd85c>] _raw_spin_lock_irqsave+0x8c/0xb0
softirqs last  enabled at (0): [<ffffafe6a5d50b28>] copy_process+0x11d8/0x3df8
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffafe6a6598a4c>] kmemleak_seq_show+0x3c/0x1e0
CPU: 1 UID: 0 PID: 136 Comm: cat Tainted: G            E      6.11.0-rt7+ ni#34
Tainted: [E]=UNSIGNED_MODULE
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0xa0/0x128
 show_stack+0x1c/0x30
 dump_stack_lvl+0xe8/0x198
 dump_stack+0x18/0x20
 rt_spin_lock+0x8c/0x1a8
 avc_perm_nonode+0xa0/0x150
 cred_has_capability.isra.0+0x118/0x218
 selinux_capable+0x50/0x80
 security_capable+0x7c/0xd0
 has_ns_capability_noaudit+0x94/0x1b0
 has_capability_noaudit+0x20/0x30
 restricted_pointer+0x21c/0x4b0
 pointer+0x298/0x760
 vsnprintf+0x330/0xf70
 seq_printf+0x178/0x218
 print_unreferenced+0x1a4/0x2d0
 kmemleak_seq_show+0xd0/0x1e0
 seq_read_iter+0x354/0xe30
 seq_read+0x250/0x378
 full_proxy_read+0xd8/0x148
 vfs_read+0x190/0x918
 ksys_read+0xf0/0x1e0
 __arm64_sys_read+0x70/0xa8
 invoke_syscall.constprop.0+0xd4/0x1d8
 el0_svc+0x50/0x158
 el0t_64_sync+0x17c/0x180

%pS and %pK, in the same back trace line, are redundant, and %pS can void
%pK service in certain contexts.

%pS alone already provides the necessary information, and if it cannot
resolve the symbol, it falls back to printing the raw address voiding
the original intent behind the %pK.

Additionally, %pK requires a privilege check CAP_SYSLOG enforced through
the LSM, which can trigger a "sleeping function called from invalid
context" warning under RT_PREEMPT kernels when the check occurs in an
atomic context. This issue may also affect other LSMs.

This change avoids the unnecessary privilege check and resolves the
sleeping function warning without any loss of information.

Link: https://lkml.kernel.org/r/20241217142032.55793-1-acarmina@redhat.com
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <acarmina@redhat.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Clément Léger <clement.leger@bootlin.com>
Cc: Alessandro Carminati <acarmina@redhat.com>
Cc: Eric Chanudet <echanude@redhat.com>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usercw88 pushed a commit to usercw88/linux that referenced this pull request Feb 4, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 ni#1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 ni#2 [ffff80002cb6f990] schedule at ffff800008abc50c
 ni#3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 ni#4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 ni#5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 ni#6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 ni#7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 ni#8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 ni#9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usercw88 pushed a commit to usercw88/linux that referenced this pull request Feb 4, 2025
[ Upstream commit 2c36880 ]

Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.

 =====================================================
 WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 6.12.0+ ni#4 Not tainted
 -----------------------------------------------------
 charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
 ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]

 and this task is already holding:
 ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
 which would create a new lock dependency:
  (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}

 but this new dependency connects a SOFTIRQ-irq-safe lock:
  (&x->lock){+.-.}-{3:3}

 ... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1be/0x520
   _raw_spin_lock_bh+0x34/0x40
   xfrm_timer_handler+0x91/0xd70
   __hrtimer_run_queues+0x1dd/0xa60
   hrtimer_run_softirq+0x146/0x2e0
   handle_softirqs+0x266/0x860
   irq_exit_rcu+0x115/0x1a0
   sysvec_apic_timer_interrupt+0x6e/0x90
   asm_sysvec_apic_timer_interrupt+0x16/0x20
   default_idle+0x13/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2da/0x320
   cpu_startup_entry+0x50/0x60
   start_secondary+0x213/0x2a0
   common_startup_64+0x129/0x138

 to a SOFTIRQ-irq-unsafe lock:
  (&xa->xa_lock#24){+.+.}-{3:3}

 ... which became SOFTIRQ-irq-unsafe at:
 ...
   lock_acquire+0x1be/0x520
   _raw_spin_lock+0x2c/0x40
   xa_set_mark+0x70/0x110
   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
   xfrm_dev_state_add+0x3bb/0xd70
   xfrm_add_sa+0x2451/0x4a90
   xfrm_user_rcv_msg+0x493/0x880
   netlink_rcv_skb+0x12e/0x380
   xfrm_netlink_rcv+0x6d/0x90
   netlink_unicast+0x42f/0x740
   netlink_sendmsg+0x745/0xbe0
   __sock_sendmsg+0xc5/0x190
   __sys_sendto+0x1fe/0x2c0
   __x64_sys_sendto+0xdc/0x1b0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xa->xa_lock#24);
                                local_irq_disable();
                                lock(&x->lock);
                                lock(&xa->xa_lock#24);
   <Interrupt>
     lock(&x->lock);

  *** DEADLOCK ***

 2 locks held by charon/1337:
  #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
  ni#1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30

 the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&x->lock){+.-.}-{3:3} ops: 29 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_alloc_spi+0xc0/0xe60
                     xfrm_alloc_userspi+0x5f6/0xbc0
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    IN-SOFTIRQ-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_timer_handler+0x91/0xd70
                     __hrtimer_run_queues+0x1dd/0xa60
                     hrtimer_run_softirq+0x146/0x2e0
                     handle_softirqs+0x266/0x860
                     irq_exit_rcu+0x115/0x1a0
                     sysvec_apic_timer_interrupt+0x6e/0x90
                     asm_sysvec_apic_timer_interrupt+0x16/0x20
                     default_idle+0x13/0x20
                     default_idle_call+0x67/0xa0
                     do_idle+0x2da/0x320
                     cpu_startup_entry+0x50/0x60
                     start_secondary+0x213/0x2a0
                     common_startup_64+0x129/0x138
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    xfrm_alloc_spi+0xc0/0xe60
                    xfrm_alloc_userspi+0x5f6/0xbc0
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffff87f9cd20>] __key.18+0x0/0x40

 the dependencies between the lock to be acquired
  and SOFTIRQ-irq-unsafe lock:
 -> (&xa->xa_lock#24){+.+.}-{3:3} ops: 9 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    SOFTIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock+0x2c/0x40
                     xa_set_mark+0x70/0x110
                     mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                    xfrm_dev_state_add+0x3bb/0xd70
                    xfrm_add_sa+0x2451/0x4a90
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffffa078ff60>] __key.48+0x0/0xfffffffffff210a0 [mlx5_core]
  ... acquired at:
    __lock_acquire+0x30a0/0x5040
    lock_acquire+0x1be/0x520
    _raw_spin_lock_bh+0x34/0x40
    mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
    xfrm_dev_state_delete+0x90/0x160
    __xfrm_state_delete+0x662/0xae0
    xfrm_state_delete+0x1e/0x30
    xfrm_del_sa+0x1c2/0x340
    xfrm_user_rcv_msg+0x493/0x880
    netlink_rcv_skb+0x12e/0x380
    xfrm_netlink_rcv+0x6d/0x90
    netlink_unicast+0x42f/0x740
    netlink_sendmsg+0x745/0xbe0
    __sock_sendmsg+0xc5/0x190
    __sys_sendto+0x1fe/0x2c0
    __x64_sys_sendto+0xdc/0x1b0
    do_syscall_64+0x6d/0x140
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

 stack backtrace:
 CPU: 7 UID: 0 PID: 1337 Comm: charon Not tainted 6.12.0+ ni#4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x74/0xd0
  check_irq_usage+0x12e8/0x1d90
  ? print_shortest_lock_dependencies_backwards+0x1b0/0x1b0
  ? check_chain_key+0x1bb/0x4c0
  ? __lockdep_reset_lock+0x180/0x180
  ? check_path.constprop.0+0x24/0x50
  ? mark_lock+0x108/0x2fb0
  ? print_circular_bug+0x9b0/0x9b0
  ? mark_lock+0x108/0x2fb0
  ? print_usage_bug.part.0+0x670/0x670
  ? check_prev_add+0x1c4/0x2310
  check_prev_add+0x1c4/0x2310
  __lock_acquire+0x30a0/0x5040
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  lock_acquire+0x1be/0x520
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  ? lockdep_hardirqs_on_prepare+0x400/0x400
  ? __xfrm_state_delete+0x5f0/0xae0
  ? lock_downgrade+0x6b0/0x6b0
  _raw_spin_lock_bh+0x34/0x40
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  xfrm_dev_state_delete+0x90/0x160
  __xfrm_state_delete+0x662/0xae0
  xfrm_state_delete+0x1e/0x30
  xfrm_del_sa+0x1c2/0x340
  ? xfrm_get_sa+0x250/0x250
  ? check_chain_key+0x1bb/0x4c0
  xfrm_user_rcv_msg+0x493/0x880
  ? copy_sec_ctx+0x270/0x270
  ? check_chain_key+0x1bb/0x4c0
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  netlink_rcv_skb+0x12e/0x380
  ? copy_sec_ctx+0x270/0x270
  ? netlink_ack+0xd90/0xd90
  ? netlink_deliver_tap+0xcd/0xb60
  xfrm_netlink_rcv+0x6d/0x90
  netlink_unicast+0x42f/0x740
  ? netlink_attachskb+0x730/0x730
  ? lock_acquire+0x1be/0x520
  netlink_sendmsg+0x745/0xbe0
  ? netlink_unicast+0x740/0x740
  ? __might_fault+0xbb/0x170
  ? netlink_unicast+0x740/0x740
  __sock_sendmsg+0xc5/0x190
  ? fdget+0x163/0x1d0
  __sys_sendto+0x1fe/0x2c0
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_user_addr_fault+0x856/0xe30
  ? lock_acquire+0x1be/0x520
  ? __task_pid_nr_ns+0x117/0x410
  ? lock_downgrade+0x6b0/0x6b0
  __x64_sys_sendto+0xdc/0x1b0
  ? lockdep_hardirqs_on_prepare+0x284/0x400
  do_syscall_64+0x6d/0x140
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 RIP: 0033:0x7f7d31291ba4
 Code: 7d e8 89 4d d4 e8 4c 42 f7 ff 44 8b 4d d0 4c 8b 45 c8 89 c3 44 8b 55 d4 8b 7d e8 b8 2c 00 00 00 48 8b 55 d8 48 8b 75 e0 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 45 e8 e8 99 42 f7 ff 48 8b 45
 RSP: 002b:00007f7d2ccd94f0 EFLAGS: 00000297 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7d31291ba4
 RDX: 0000000000000028 RSI: 00007f7d2ccd96a0 RDI: 000000000000000a
 RBP: 00007f7d2ccd9530 R08: 00007f7d2ccd9598 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000028
 R13: 00007f7d2ccd9598 R14: 00007f7d2ccd96a0 R15: 00000000000000e1
  </TASK>

Fixes: 4c24272 ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
usercw88 pushed a commit to usercw88/linux that referenced this pull request Feb 4, 2025
commit 9860370 upstream.

irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ ni#69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] ni#1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] ni#2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] ni#3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] ni#4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ ni#69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250110163354.2012654-1-sean.anderson@linux.dev
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3 participants