latest changes with all raw register access removed #2
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some of the mask/unmask parts im not sure of, ive marked them with comments everything seems to work, it can RX and TX normaly
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…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 raspberrypi#4 [d72d3c00] do_page_fault at c05c72ec raspberrypi#5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 raspberrypi#6 [d72d3cb4] isolate_migratepages at c030b15a raspberrypi#7 [d72d3d14] zone_watermark_ok at c02d26cb raspberrypi#8 [d72d3d2c] compact_zone at c030b8de raspberrypi#9 [d72d3d68] compact_zone_order at c030bba1 raspberrypi#10 [d72d3db4] try_to_compact_pages at c030bc84 raspberrypi#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 raspberrypi#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 raspberrypi#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 raspberrypi#14 [d72d3eb8] alloc_pages_vma at c030a845 raspberrypi#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb raspberrypi#16 [d72d3f00] handle_mm_fault at c02f36c6 raspberrypi#17 [d72d3f30] do_page_fault at c05c70ed raspberrypi#18 [d72d3fb0] error_code (via page_fault) at c05c47a4 EAX: b71ff00 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b704871 upstream. coretemp tries to access core_data array beyond bounds on cpu unplug if core id of the cpu if more than NUM_REAL_CORES-1. BUG: unable to handle kernel NULL pointer dereference at 000000000000013c IP: [<ffffffffa00159af>] coretemp_cpu_callback+0x93/0x1ba [coretemp] PGD 673e5a067 PUD 66e9b3067 PMD 0 Oops: 0000 [#1] SMP CPU 79 Modules linked in: sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bnep bluetooth rfkill ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter nf_conntrack_ipv4 nf_defrag_ipv4 ip6_tables xt_state nf_conntrack coretemp crc32c_intel asix tpm_tis pcspkr usbnet iTCO_wdt i2c_i801 microcode mii joydev tpm i2c_core iTCO_vendor_support tpm_bios i7core_edac igb ioatdma edac_core dca megaraid_sas [last unloaded: oprofile] Pid: 3315, comm: set-cpus Tainted: G W 3.4.0-rc5+ #2 QCI QSSC-S4R/QSSC-S4R RIP: 0010:[<ffffffffa00159af>] [<ffffffffa00159af>] coretemp_cpu_callback+0x93/0x1ba [coretemp] RSP: 0018:ffff880472fb3d48 EFLAGS: 00010246 RAX: 0000000000000124 RBX: 0000000000000034 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000046 RDI: 0000000000000246 RBP: ffff880472fb3d88 R08: ffff88077fcd36c0 R09: 0000000000000001 R10: ffffffff8184bc48 R11: 0000000000000000 R12: ffff880273095800 R13: 0000000000000013 R14: ffff8802730a1810 R15: 0000000000000000 FS: 00007f694a20f720(0000) GS:ffff88077fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 000000000000013c CR3: 000000067209b000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process set-cpus (pid: 3315, threadinfo ffff880472fb2000, task ffff880471fa0000) Stack: ffff880277b4c308 0000000000000003 ffff880472fb3d88 0000000000000005 0000000000000034 00000000ffffffd1 ffffffff81cadc70 ffff880472fb3e14 ffff880472fb3dc8 ffffffff8161f48d ffff880471fa0000 0000000000000034 Call Trace: [<ffffffff8161f48d>] notifier_call_chain+0x4d/0x70 [<ffffffff8107f1be>] __raw_notifier_call_chain+0xe/0x10 [<ffffffff81059d30>] __cpu_notify+0x20/0x40 [<ffffffff815fa251>] _cpu_down+0x81/0x270 [<ffffffff815fa477>] cpu_down+0x37/0x50 [<ffffffff815fd6a3>] store_online+0x63/0xc0 [<ffffffff813c7078>] dev_attr_store+0x18/0x30 [<ffffffff811f02cf>] sysfs_write_file+0xef/0x170 [<ffffffff81180443>] vfs_write+0xb3/0x180 [<ffffffff8118076a>] sys_write+0x4a/0x90 [<ffffffff816236a9>] system_call_fastpath+0x16/0x1b Code: 48 c7 c7 94 60 01 a0 44 0f b7 ac 10 ac 00 00 00 31 c0 e8 41 b7 5f e1 41 83 c5 02 49 63 c5 49 8b 44 c4 10 48 85 c0 74 56 45 31 ff <39> 58 18 75 4e eb 1f 49 63 d7 4c 89 f7 48 89 45 c8 48 6b d2 28 RIP [<ffffffffa00159af>] coretemp_cpu_callback+0x93/0x1ba [coretemp] RSP <ffff880472fb3d48> CR2: 000000000000013c Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 2608bee upstream. As observed and suggested by Tushar Gosavi... --------- readdir calls these function to send TRANS2_FIND_FIRST and TRANS2_FIND_NEXT command to the server. The current cifs module is not specifying CIFS_SEARCH_BACKUP_SEARCH flag while sending these command when backupuid/backupgid is specified. This can be resolved by specifying CIFS_SEARCH_BACKUP_SEARCH flag. --------- Reported-and-Tested-by: Tushar Gosavi <tugosavi@in.ibm.com> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit e5851da upstream. Remove spinlock as atomic_t can be used instead. Note we use only 16 lower bits, upper bits are changed but we impilcilty cast to u16. This fix possible deadlock on IBSS mode reproted by lockdep: ================================= [ INFO: inconsistent lock state ] 3.4.0-wl+ raspberrypi#4 Not tainted --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kworker/u:2/30374 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&intf->seqlock)->rlock){+.?...}, at: [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] {IN-SOFTIRQ-W} state was registered at: [<c04978ab>] __lock_acquire+0x47b/0x1050 [<c0498504>] lock_acquire+0x84/0xf0 [<c0835733>] _raw_spin_lock+0x33/0x40 [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f9979f2a>] rt2x00queue_write_tx_frame+0x1a/0x300 [rt2x00lib] [<f997834f>] rt2x00mac_tx+0x7f/0x380 [rt2x00lib] [<f98fe363>] __ieee80211_tx+0x1b3/0x300 [mac80211] [<f98ffdf5>] ieee80211_tx+0x105/0x130 [mac80211] [<f99000dd>] ieee80211_xmit+0xad/0x100 [mac80211] [<f9900519>] ieee80211_subif_start_xmit+0x2d9/0x930 [mac80211] [<c0782e87>] dev_hard_start_xmit+0x307/0x660 [<c079bb71>] sch_direct_xmit+0xa1/0x1e0 [<c0784bb3>] dev_queue_xmit+0x183/0x730 [<c078c27a>] neigh_resolve_output+0xfa/0x1e0 [<c07b436a>] ip_finish_output+0x24a/0x460 [<c07b4897>] ip_output+0xb7/0x100 [<c07b2d60>] ip_local_out+0x20/0x60 [<c07e01ff>] igmpv3_sendpack+0x4f/0x60 [<c07e108f>] igmp_ifc_timer_expire+0x29f/0x330 [<c04520fc>] run_timer_softirq+0x15c/0x2f0 [<c0449e3e>] __do_softirq+0xae/0x1e0 irq event stamp: 18380437 hardirqs last enabled at (18380437): [<c0526027>] __slab_alloc.clone.3+0x67/0x5f0 hardirqs last disabled at (18380436): [<c0525ff3>] __slab_alloc.clone.3+0x33/0x5f0 softirqs last enabled at (18377616): [<c0449eb3>] __do_softirq+0x123/0x1e0 softirqs last disabled at (18377611): [<c041278d>] do_softirq+0x9d/0xe0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&intf->seqlock)->rlock); <Interrupt> lock(&(&intf->seqlock)->rlock); *** DEADLOCK *** 4 locks held by kworker/u:2/30374: #0: (wiphy_name(local->hw.wiphy)){++++.+}, at: [<c045cf99>] process_one_work+0x109/0x3f0 #1: ((&sdata->work)){+.+.+.}, at: [<c045cf99>] process_one_work+0x109/0x3f0 #2: (&ifibss->mtx){+.+.+.}, at: [<f98f005b>] ieee80211_ibss_work+0x1b/0x470 [mac80211] #3: (&intf->beacon_skb_mutex){+.+...}, at: [<f997a644>] rt2x00queue_update_beacon+0x24/0x50 [rt2x00lib] stack backtrace: Pid: 30374, comm: kworker/u:2 Not tainted 3.4.0-wl+ raspberrypi#4 Call Trace: [<c04962a6>] print_usage_bug+0x1f6/0x220 [<c0496a12>] mark_lock+0x2c2/0x300 [<c0495ff0>] ? check_usage_forwards+0xc0/0xc0 [<c04978ec>] __lock_acquire+0x4bc/0x1050 [<c0527890>] ? __kmalloc_track_caller+0x1c0/0x1d0 [<c0777fb6>] ? copy_skb_header+0x26/0x90 [<c0498504>] lock_acquire+0x84/0xf0 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<c0835733>] _raw_spin_lock+0x33/0x40 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f997a5cf>] rt2x00queue_update_beacon_locked+0x5f/0xb0 [rt2x00lib] [<f997a64d>] rt2x00queue_update_beacon+0x2d/0x50 [rt2x00lib] [<f9977e3a>] rt2x00mac_bss_info_changed+0x1ca/0x200 [rt2x00lib] [<f9977c70>] ? rt2x00mac_remove_interface+0x70/0x70 [rt2x00lib] [<f98e4dd0>] ieee80211_bss_info_change_notify+0xe0/0x1d0 [mac80211] [<f98ef7b8>] __ieee80211_sta_join_ibss+0x3b8/0x610 [mac80211] [<c0496ab4>] ? mark_held_locks+0x64/0xc0 [<c0440012>] ? virt_efi_query_capsule_caps+0x12/0x50 [<f98efb09>] ieee80211_sta_join_ibss+0xf9/0x140 [mac80211] [<f98f0456>] ieee80211_ibss_work+0x416/0x470 [mac80211] [<c0496d8b>] ? trace_hardirqs_on+0xb/0x10 [<c077683b>] ? skb_dequeue+0x4b/0x70 [<f98f207f>] ieee80211_iface_work+0x13f/0x230 [mac80211] [<c045cf99>] ? process_one_work+0x109/0x3f0 [<c045d015>] process_one_work+0x185/0x3f0 [<c045cf99>] ? process_one_work+0x109/0x3f0 [<f98f1f40>] ? ieee80211_teardown_sdata+0xa0/0xa0 [mac80211] [<c045ed86>] worker_thread+0x116/0x270 [<c045ec70>] ? manage_workers+0x1e0/0x1e0 [<c0462f64>] kthread+0x84/0x90 [<c0462ee0>] ? __init_kthread_worker+0x60/0x60 [<c083d382>] kernel_thread_helper+0x6/0x10 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Helmut Schaa <helmut.schaa@googlemail.com> Acked-by: Gertjan van Wingerde <gwingerde@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit e35fca4 upstream. Some edac drivers register themselves as mce decoders via notifier_chain. But in current notifier_chain implementation logic, it doesn't accept same notifier registered twice. If so, it will be wrong when adding/removing the element from the list. For example, on one SandyBridge platform, remove module sb_edac and then trigger one error, it will hit oops because it has no mce decoder registered but related notifier_chain still points to an invalid callback function. Here is an example: Call Trace: [<ffffffff8150ef6a>] atomic_notifier_call_chain+0x1a/0x20 [<ffffffff8102b936>] mce_log+0x46/0x180 [<ffffffff8102eaea>] apei_mce_report_mem_error+0x4a/0x60 [<ffffffff812e19d2>] ghes_do_proc+0x192/0x210 [<ffffffff812e2066>] ghes_proc+0x46/0x70 [<ffffffff812e20d8>] ghes_notify_sci+0x48/0x80 [<ffffffff8150ef05>] notifier_call_chain+0x55/0x80 [<ffffffff81076f1a>] __blocking_notifier_call_chain+0x5a/0x80 [<ffffffff812aea11>] ? acpi_os_wait_events_complete+0x23/0x23 [<ffffffff81076f56>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff812ddc4d>] acpi_hed_notify+0x19/0x1b [<ffffffff812b16bd>] acpi_device_notify+0x19/0x1b [<ffffffff812beb38>] acpi_ev_notify_dispatch+0x67/0x7f [<ffffffff812aea3a>] acpi_os_execute_deferred+0x29/0x36 [<ffffffff81069dc2>] process_one_work+0x132/0x450 [<ffffffff8106bbcb>] worker_thread+0x17b/0x3c0 [<ffffffff8106ba50>] ? manage_workers+0x120/0x120 [<ffffffff81070aee>] kthread+0x9e/0xb0 [<ffffffff81514724>] kernel_thread_helper+0x4/0x10 [<ffffffff81070a50>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff81514720>] ? gs_change+0x13/0x13 Code: f3 49 89 d4 45 85 ed 4d 89 c6 48 8b 0f 74 48 48 85 c9 75 17 eb 41 0f 1f 80 00 00 00 00 41 83 ed 01 4c 89 f9 74 22 4d 85 ff 74 1d <4c> 8b 79 08 4c 89 e2 48 89 de 48 89 cf ff 11 4d 85 f6 74 04 41 RIP [<ffffffff8150eef6>] notifier_call_chain+0x46/0x80 RSP <ffff88042868fb20> CR2: ffffffffa01af838 ---[ end trace 0100930068e73e6f ]--- BUG: unable to handle kernel paging request at fffffffffffffff8 IP: [<ffffffff810705b0>] kthread_data+0x10/0x20 PGD 1a0d067 PUD 1a0e067 PMD 0 Oops: 0000 [#2] SMP Only i7core_edac and sb_edac have such issues because they have more than one memory controller which means they have to register mce decoder many times. Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> [bwh: Backported to 3.2: drivers call atomic_notifier_chain_{,un}register() directly] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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…condition commit 26c1917 upstream. When holding the mmap_sem for reading, pmd_offset_map_lock should only run on a pmd_t that has been read atomically from the pmdp pointer, otherwise we may read only half of it leading to this crash. PID: 11679 TASK: f06e8000 CPU: 3 COMMAND: "do_race_2_panic" #0 [f06a9dd8] crash_kexec at c049b5ec #1 [f06a9e2c] oops_end at c083d1c2 #2 [f06a9e40] no_context at c0433ded #3 [f06a9e64] bad_area_nosemaphore at c043401a raspberrypi#4 [f06a9e6c] __do_page_fault at c0434493 raspberrypi#5 [f06a9eec] do_page_fault at c083eb45 raspberrypi#6 [f06a9f04] error_code (via page_fault) at c083c5d5 EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP: 00000000 DS: 007b ESI: 9e201000 ES: 007b EDI: 01fb4700 GS: 00e0 CS: 0060 EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246 raspberrypi#7 [f06a9f38] _spin_lock at c083bc14 raspberrypi#8 [f06a9f44] sys_mincore at c0507b7d raspberrypi#9 [f06a9fb0] system_call at c083becd start len EAX: ffffffda EBX: 9e200000 ECX: 00001000 EDX: 6228537f DS: 007b ESI: 00000000 ES: 007b EDI: 003d0f00 SS: 007b ESP: 62285354 EBP: 62285388 GS: 0033 CS: 0073 EIP: 00291416 ERR: 000000da EFLAGS: 00000286 This should be a longstanding bug affecting x86 32bit PAE without THP. Only archs with 64bit large pmd_t and 32bit unsigned long should be affected. With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad() would partly hide the bug when the pmd transition from none to stable, by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is enabled a new set of problem arises by the fact could then transition freely in any of the none, pmd_trans_huge or pmd_trans_stable states. So making the barrier in pmd_none_or_trans_huge_or_clear_bad() unconditional isn't good idea and it would be a flakey solution. This should be fully fixed by introducing a pmd_read_atomic that reads the pmd in order with THP disabled, or by reading the pmd atomically with cmpxchg8b with THP enabled. Luckily this new race condition only triggers in the places that must already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix is localized there but this bug is not related to THP. NOTE: this can trigger on x86 32bit systems with PAE enabled with more than 4G of ram, otherwise the high part of the pmd will never risk to be truncated because it would be zero at all times, in turn so hiding the SMP race. This bug was discovered and fully debugged by Ulrich, quote: ---- [..] pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and eax. 496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd) 497 { 498 /* depend on compiler for an atomic pmd read */ 499 pmd_t pmdval = *pmd; // edi = pmd pointer 0xc0507a74 <sys_mincore+548>: mov 0x8(%esp),%edi ... // edx = PTE page table high address 0xc0507a84 <sys_mincore+564>: mov 0x4(%edi),%edx ... // eax = PTE page table low address 0xc0507a8e <sys_mincore+574>: mov (%edi),%eax [..] Please note that the PMD is not read atomically. These are two "mov" instructions where the high order bits of the PMD entry are fetched first. Hence, the above machine code is prone to the following race. - The PMD entry {high|low} is 0x0000000000000000. The "mov" at 0xc0507a84 loads 0x00000000 into edx. - A page fault (on another CPU) sneaks in between the two "mov" instructions and instantiates the PMD. - The PMD entry {high|low} is now 0x00000003fda38067. The "mov" at 0xc0507a8e loads 0xfda38067 into eax. ---- Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Nov 5, 2012
commit fe20b39 upstream. reg_timeout_work() calls restore_regulatory_settings() which takes cfg80211_mutex. reg_set_request_processed() already holds cfg80211_mutex before calling cancel_delayed_work_sync(reg_timeout), so it might deadlock. Call the async cancel_delayed_work instead, in order to avoid the potential deadlock. This is the relevant lockdep warning: cfg80211: Calling CRDA for country: XX ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc5-wl+ raspberrypi#26 Not tainted ------------------------------------------------------- kworker/0:2/1391 is trying to acquire lock: (cfg80211_mutex){+.+.+.}, at: [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211] but task is already holding lock: ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((reg_timeout).work){+.+...}: [<c008fd44>] validate_chain+0xb94/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c005b600>] wait_on_work+0x4c/0x154 [<c005c000>] __cancel_work_timer+0xd4/0x11c [<c005c064>] cancel_delayed_work_sync+0x1c/0x20 [<bf28b274>] reg_set_request_processed+0x50/0x78 [cfg80211] [<bf28bd84>] set_regdom+0x550/0x600 [cfg80211] [<bf294cd8>] nl80211_set_reg+0x218/0x258 [cfg80211] [<c03c7738>] genl_rcv_msg+0x1a8/0x1e8 [<c03c6a00>] netlink_rcv_skb+0x5c/0xc0 [<c03c7584>] genl_rcv+0x28/0x34 [<c03c6720>] netlink_unicast+0x15c/0x228 [<c03c6c7c>] netlink_sendmsg+0x218/0x298 [<c03933c8>] sock_sendmsg+0xa4/0xc0 [<c039406c>] __sys_sendmsg+0x1e4/0x268 [<c0394228>] sys_sendmsg+0x4c/0x70 [<c0013840>] ret_fast_syscall+0x0/0x3c -> #1 (reg_mutex){+.+.+.}: [<c008fd44>] validate_chain+0xb94/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c04734dc>] mutex_lock_nested+0x48/0x320 [<bf28b2cc>] reg_todo+0x30/0x538 [cfg80211] [<c0059f44>] process_one_work+0x2a0/0x480 [<c005a4b4>] worker_thread+0x1bc/0x2bc [<c0061148>] kthread+0x98/0xa4 [<c0014af4>] kernel_thread_exit+0x0/0x8 -> #0 (cfg80211_mutex){+.+.+.}: [<c008ed58>] print_circular_bug+0x68/0x2cc [<c008fb28>] validate_chain+0x978/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c04734dc>] mutex_lock_nested+0x48/0x320 [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211] [<bf28b200>] reg_timeout_work+0x1c/0x20 [cfg80211] [<c0059f44>] process_one_work+0x2a0/0x480 [<c005a4b4>] worker_thread+0x1bc/0x2bc [<c0061148>] kthread+0x98/0xa4 [<c0014af4>] kernel_thread_exit+0x0/0x8 other info that might help us debug this: Chain exists of: cfg80211_mutex --> reg_mutex --> (reg_timeout).work Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((reg_timeout).work); lock(reg_mutex); lock((reg_timeout).work); lock(cfg80211_mutex); *** DEADLOCK *** 2 locks held by kworker/0:2/1391: #0: (events){.+.+.+}, at: [<c0059e94>] process_one_work+0x1f0/0x480 #1: ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480 stack backtrace: [<c001b928>] (unwind_backtrace+0x0/0x12c) from [<c0471d3c>] (dump_stack+0x20/0x24) [<c0471d3c>] (dump_stack+0x20/0x24) from [<c008ef70>] (print_circular_bug+0x280/0x2cc) [<c008ef70>] (print_circular_bug+0x280/0x2cc) from [<c008fb28>] (validate_chain+0x978/0x10f0) [<c008fb28>] (validate_chain+0x978/0x10f0) from [<c0090b68>] (__lock_acquire+0x8c8/0x9b0) [<c0090b68>] (__lock_acquire+0x8c8/0x9b0) from [<c0090d40>] (lock_acquire+0xf0/0x114) [<c0090d40>] (lock_acquire+0xf0/0x114) from [<c04734dc>] (mutex_lock_nested+0x48/0x320) [<c04734dc>] (mutex_lock_nested+0x48/0x320) from [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) from [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) from [<c0059f44>] (process_one_work+0x2a0/0x480) [<c0059f44>] (process_one_work+0x2a0/0x480) from [<c005a4b4>] (worker_thread+0x1bc/0x2bc) [<c005a4b4>] (worker_thread+0x1bc/0x2bc) from [<c0061148>] (kthread+0x98/0xa4) [<c0061148>] (kthread+0x98/0xa4) from [<c0014af4>] (kernel_thread_exit+0x0/0x8) cfg80211: Calling CRDA to update world regulatory domain cfg80211: World regulatory domain updated: cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp) cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) Signed-off-by: Eliad Peller <eliad@wizery.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Nov 5, 2012
commit 3cf003c upstream. Jian found that when he ran fsx on a 32 bit arch with a large wsize the process and one of the bdi writeback kthreads would sometimes deadlock with a stack trace like this: crash> bt PID: 2789 TASK: f02edaa0 CPU: 3 COMMAND: "fsx" #0 [eed63cbc] schedule at c083c5b3 #1 [eed63d80] kmap_high at c0500ec8 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs] #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs] raspberrypi#4 [eed63e50] do_writepages at c04f3e32 raspberrypi#5 [eed63e54] __filemap_fdatawrite_range at c04e152a raspberrypi#6 [eed63ea4] filemap_fdatawrite at c04e1b3e raspberrypi#7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs] raspberrypi#8 [eed63ecc] do_sync_write at c052d202 raspberrypi#9 [eed63f74] vfs_write at c052d4ee raspberrypi#10 [eed63f94] sys_write at c052df4c raspberrypi#11 [eed63fb0] ia32_sysenter_target at c0409a98 EAX: 00000004 EBX: 00000003 ECX: abd73b73 EDX: 012a65c6 DS: 007b ESI: 012a65c6 ES: 007b EDI: 00000000 SS: 007b ESP: bf8db178 EBP: bf8db1f8 GS: 0033 CS: 0073 EIP: 40000424 ERR: 00000004 EFLAGS: 00000246 Each task would kmap part of its address array before getting stuck, but not enough to actually issue the write. This patch fixes this by serializing the marshal_iov operations for async reads and writes. The idea here is to ensure that cifs aggressively tries to populate a request before attempting to fulfill another one. As soon as all of the pages are kmapped for a request, then we can unlock and allow another one to proceed. There's no need to do this serialization on non-CONFIG_HIGHMEM arches however, so optimize all of this out when CONFIG_HIGHMEM isn't set. Reported-by: Jian Li <jiali@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Nov 5, 2012
…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 raspberrypi#4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] raspberrypi#5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] raspberrypi#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 raspberrypi#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 raspberrypi#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 raspberrypi#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f raspberrypi#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e raspberrypi#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f raspberrypi#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad raspberrypi#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 raspberrypi#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a raspberrypi#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 raspberrypi#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b raspberrypi#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 raspberrypi#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c raspberrypi#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 raspberrypi#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 raspberrypi#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] raspberrypi#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] raspberrypi#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 raspberrypi#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 raspberrypi#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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