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Kernel built for lesser CPU. #11

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hexameron opened this issue Apr 28, 2012 · 2 comments
Closed

Kernel built for lesser CPU. #11

hexameron opened this issue Apr 28, 2012 · 2 comments

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@hexameron
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The Linux kernel has options for CPU_V6K , but your kernel patches force CPU_V6 only. The kernel overrides your toolchain so that kernel modules are being built for v6 not v6k

@popcornmix
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Good point. I've locally switched to CPU_V6K and it still works. Looking though the change in disassembly there's very little difference. Any idea what could be improved with this change?

@hexameron
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From the source I would not expect a lot of difference, and arch/arm/Makefile still uses:
tune-$(CONFIG_CPU_V6K) :=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)

My main concern is that I expected readelf to tell me that your kernel modules use vfp, and it doesn`t.

bootc pushed a commit to bootc/linux-rpi-orig that referenced this issue May 8, 2012
…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
 raspberrypi#1 [d72d3b24] oops_end at c05c5322
 raspberrypi#2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 raspberrypi#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>
popcornmix pushed a commit to popcornmix/linux that referenced this issue Aug 16, 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
 raspberrypi#1 [eed63d80] kmap_high at c0500ec8
 raspberrypi#2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 raspberrypi#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>
popcornmix pushed a commit to popcornmix/linux that referenced this issue Aug 16, 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
     raspberrypi#1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     raspberrypi#2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     raspberrypi#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>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
Printing the "start_ip" for every secondary cpu is very noisy on a large
system - and doesn't add any value. Drop this message.

Console log before:
Booting Node   0, Processors  #1
smpboot cpu 1: start_ip = 96000
 #2
smpboot cpu 2: start_ip = 96000
 #3
smpboot cpu 3: start_ip = 96000
 #4
smpboot cpu 4: start_ip = 96000
       ...
 #31
smpboot cpu 31: start_ip = 96000
Brought up 32 CPUs

Console log after:
Booting Node   0, Processors  #1 #2 #3 #4 #5 #6 #7 Ok.
Booting Node   1, Processors  #8 #9 #10 #11 #12 #13 #14 #15 Ok.
Booting Node   0, Processors  #16 #17 #18 #19 #20 #21 #22 #23 Ok.
Booting Node   1, Processors  #24 #25 #26 #27 #28 #29 #30 #31
Brought up 32 CPUs

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4f452eb42507460426@agluck-desktop.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
fixed:
WARNING: please, no space before tabs
#11: FILE: adt7411.c:11:
+ * ^I  use power-down mode for suspend?, interrupt handling?$

not fixed as all other macros around it are the same structure and this one is only 2 chars longer:
WARNING: line over 80 characters
#229: FILE: adt7411.c:229:
+static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
The warning below triggers on AMD MCM packages because physical package
IDs on the cores of a _physical_ socket are the same. I.e., this field
says which CPUs belong to the same physical package.

However, the same two CPUs belong to two different internal, i.e.
"logical" nodes in the same physical socket which is reflected in the
CPU-to-node map on x86 with NUMA.

Which makes this check wrong on the above topologies so circumvent it.

[    0.444413] Booting Node   0, Processors  #1 #2 #3 #4 #5 Ok.
[    0.461388] ------------[ cut here ]------------
[    0.465997] WARNING: at arch/x86/kernel/smpboot.c:310 topology_sane.clone.1+0x6e/0x81()
[    0.473960] Hardware name: Dinar
[    0.477170] sched: CPU #6's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
[    0.486860] Booting Node   1, Processors  #6
[    0.491104] Modules linked in:
[    0.494141] Pid: 0, comm: swapper/6 Not tainted 3.4.0+ #1
[    0.499510] Call Trace:
[    0.501946]  [<ffffffff8144bf92>] ? topology_sane.clone.1+0x6e/0x81
[    0.508185]  [<ffffffff8102f1fc>] warn_slowpath_common+0x85/0x9d
[    0.514163]  [<ffffffff8102f2b7>] warn_slowpath_fmt+0x46/0x48
[    0.519881]  [<ffffffff8144bf92>] topology_sane.clone.1+0x6e/0x81
[    0.525943]  [<ffffffff8144c234>] set_cpu_sibling_map+0x251/0x371
[    0.532004]  [<ffffffff8144c4ee>] start_secondary+0x19a/0x218
[    0.537729] ---[ end trace 4eaa2a86a8e2da22 ]---
[    0.628197]  #7 #8 #9 #10 #11 Ok.
[    0.807108] Booting Node   3, Processors  #12 #13 #14 #15 #16 #17 Ok.
[    0.897587] Booting Node   2, Processors  #18 #19 #20 #21 #22 #23 Ok.
[    0.917443] Brought up 24 CPUs

We ran a topology sanity check test we have here on it and
it all looks ok... hopefully :).

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120529135442.GE29157@aftab.osrc.amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
usbnet_disconnect() will set intfdata to NULL before calling
the minidriver unbind function.  The cdc_wdm subdriver cannot
know that it is disconnecting until the qmi_wwan unbind
function has called its disconnect function.  This means that
we must be able to support the cdc_wdm subdriver operating
normally while usbnet_disconnect() is running, and in
particular that intfdata may be NULL.

The only place this matters is in qmi_wwan_cdc_wdm_manage_power
which is called from cdc_wdm.  Simply testing for NULL
intfdata there is sufficient to allow it to continue working
at all times.

Fixes this Oops where a cdc-wdm device was closed while the
USB device was disconnecting, causing wdm_release to call
qmi_wwan_cdc_wdm_manage_power after intfdata was set to
NULL by usbnet_disconnect:

[41819.087460] BUG: unable to handle kernel NULL pointer dereference at 00000080
[41819.087815] IP: [<f8640458>] qmi_wwan_manage_power+0x68/0x90 [qmi_wwan]
[41819.088028] *pdpt = 000000000314f001 *pde = 0000000000000000
[41819.088028] Oops: 0002 [#1] SMP
[41819.088028] Modules linked in: qmi_wwan option usb_wwan usbserial usbnet
cdc_wdm nls_iso8859_1 nls_cp437 vfat fat usb_storage bnep rfcomm bluetooth
parport_pc ppdev binfmt_misc iptable_nat nf_nat nf_conntrack_ipv4
nf_conntrack nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables
x_tables dm_crypt uvcvideo snd_hda_codec_realtek snd_hda_intel
videobuf2_core snd_hda_codec joydev videodev videobuf2_vmalloc
hid_multitouch snd_hwdep arc4 videobuf2_memops snd_pcm snd_seq_midi
snd_rawmidi snd_seq_midi_event ath9k mac80211 snd_seq ath9k_common ath9k_hw
ath snd_timer snd_seq_device sparse_keymap dm_multipath scsi_dh coretemp
mac_hid snd soundcore cfg80211 snd_page_alloc psmouse serio_raw microcode
lp parport dm_mirror dm_region_hash dm_log usbhid hid i915 drm_kms_helper
drm r8169 i2c_algo_bit wmi video [last unloaded: qmi_wwan]
[41819.088028]
[41819.088028] Pid: 23292, comm: qmicli Not tainted 3.4.0-5-generic #11-Ubuntu GIGABYTE T1005/T1005
[41819.088028] EIP: 0060:[<f8640458>] EFLAGS: 00010246 CPU: 1
[41819.088028] EIP is at qmi_wwan_manage_power+0x68/0x90 [qmi_wwan]
[41819.088028] EAX: 00000000 EBX: 00000000 ECX: 000000c3 EDX: 00000000
[41819.088028] ESI: c3b27658 EDI: 00000000 EBP: c298bea4 ESP: c298be98
[41819.088028]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[41819.088028] CR0: 8005003b CR2: 00000080 CR3: 3605e000 CR4: 000007f0
[41819.088028] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[41819.088028] DR6: ffff0ff0 DR7: 00000400
[41819.088028] Process qmicli (pid: 23292, ti=c298a000 task=f343b280 task.ti=c298a000)
[41819.088028] Stack:
[41819.088028]  00000000 c3b27658 e2a80d00 c298beb0 f864051a c3b27600 c298bec0 f9027099
[41819.088028]  c2fd6000 00000008 c298bef0 c1147f96 00000001 00000000 00000000 f4e54790
[41819.088028]  ecf43a00 ecf43a00 c2fd6008 c2fd6000 ebbd7600 ffffffb9 c298bf08 c1144474
[41819.088028] Call Trace:
[41819.088028]  [<f864051a>] qmi_wwan_cdc_wdm_manage_power+0x1a/0x20 [qmi_wwan]
[41819.088028]  [<f9027099>] wdm_release+0x69/0x70 [cdc_wdm]
[41819.088028]  [<c1147f96>] fput+0xe6/0x210
[41819.088028]  [<c1144474>] filp_close+0x54/0x80
[41819.088028]  [<c1046a65>] put_files_struct+0x75/0xc0
[41819.088028]  [<c1046b56>] exit_files+0x46/0x60
[41819.088028]  [<c1046f81>] do_exit+0x141/0x780
[41819.088028]  [<c107248f>] ? wake_up_state+0xf/0x20
[41819.088028]  [<c1053f48>] ? signal_wake_up+0x28/0x40
[41819.088028]  [<c1054f3b>] ? zap_other_threads+0x6b/0x80
[41819.088028]  [<c1047864>] do_group_exit+0x34/0xa0
[41819.088028]  [<c10478e8>] sys_exit_group+0x18/0x20
[41819.088028]  [<c15bb7df>] sysenter_do_call+0x12/0x28
[41819.088028] Code: 04 83 e7 01 c1 e7 03 0f b6 42 18 83 e0 f7 09 f8 88 42
18 8b 43 04 e8 48 9a dd c8 89 f0 8b 5d f4 8b 75 f8 8b 7d fc 89 ec 5d c3 90
<f0> ff 88 80 00 00 00 0f 94 c0 84 c0 75 b7 31 f6 8b 5d f4 89 f0
[41819.088028] EIP: [<f8640458>] qmi_wwan_manage_power+0x68/0x90 [qmi_wwan] SS:ESP 0068:c298be98
[41819.088028] CR2: 0000000000000080
[41819.149492] ---[ end trace 0944479ff8257f55 ]---

Reported-by: Marius Bjørnstad Kotsbak <marius.kotsbak@gmail.com>
Cc: <stable@vger.kernel.org> # v3.4
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
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]
 #4 [eed63e50] do_writepages at c04f3e32
 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 #6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 #8 [eed63ecc] do_sync_write at c052d202
 #9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#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.

Cc: <stable@vger.kernel.org>
Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
popcornmix pushed a commit that referenced this issue Oct 13, 2012
…d reasons

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
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #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>
Cc: stable@vger.kernel.org
popcornmix pushed a commit that referenced this issue Oct 13, 2012
Release the lock before mmc_signal_sdio_irq is called by mxs_mmc_irq_handler.

Backtrace:
[   79.660000] =============================================
[   79.660000] [ INFO: possible recursive locking detected ]
[   79.660000] 3.4.0-00009-g3e96082-dirty #11 Not tainted
[   79.660000] ---------------------------------------------
[   79.660000] swapper/0 is trying to acquire lock:
[   79.660000]  (&(&host->lock)->rlock#2){-.....}, at: [<c026ea3c>] mxs_mmc_enable_sdio_irq+0x18/0xd4
[   79.660000]
[   79.660000] but task is already holding lock:
[   79.660000]  (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8
[   79.660000]
[   79.660000] other info that might help us debug this:
[   79.660000]  Possible unsafe locking scenario:
[   79.660000]
[   79.660000]        CPU0
[   79.660000]        ----
[   79.660000]   lock(&(&host->lock)->rlock#2);
[   79.660000]   lock(&(&host->lock)->rlock#2);
[   79.660000]
[   79.660000]  *** DEADLOCK ***
[   79.660000]
[   79.660000]  May be due to missing lock nesting notation
[   79.660000]
[   79.660000] 1 lock held by swapper/0:
[   79.660000]  #0:  (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8
[   79.660000]
[   79.660000] stack backtrace:
[   79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c005f9c0>] (__lock_acquire+0x1948/0x1d48)
[   79.660000] [<c005f9c0>] (__lock_acquire+0x1948/0x1d48) from [<c005fea0>] (lock_acquire+0xe0/0xf8)
[   79.660000] [<c005fea0>] (lock_acquire+0xe0/0xf8) from [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58)
[   79.660000] [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4)
[   79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8)
[   79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254)
[   79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c)
[   79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110)
[   79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50)
[   79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84)
[   79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60)
[   79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40)
[   79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc)
[   79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8)
[   79.660000] BUG: spinlock lockup on CPU#0, swapper/0
[   79.660000]  lock: c398cb2c, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
[   79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144)
[   79.660000] [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144) from [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58)
[   79.660000] [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4)
[   79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8)
[   79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254)
[   79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c)
[   79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110)
[   79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50)
[   79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84)
[   79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60)
[   79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40)
[   79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc)
[   79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8)

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
popcornmix pushed a commit that referenced this issue Mar 28, 2013
commit 4992185 upstream.

Some mlme work structs are not cancelled on disassociation
nor interface deletion, which leads to them running after
the memory has been freed

There is not a clean way to cancel these in the disassociation
logic because they must be canceled outside of the ifmgd->mtx
lock, so just cancel them in mgd_stop logic that tears down
the station.

This fixes the crashes we see in 3.7.9+.  The crash stack
trace itself isn't so helpful, but this warning gives
more useful info:

WARNING: at /home/greearb/git/linux-3.7.dev.y/lib/debugobjects.c:261 debug_print_object+0x7c/0x8d()
ODEBUG: free active (active state 0) object type: work_struct hint: ieee80211_sta_monitor_work+0x0/0x14 [mac80211]
Modules linked in: [...]
Pid: 14743, comm: iw Tainted: G         C O 3.7.9+ #11
Call Trace:
 [<ffffffff81087ef8>] warn_slowpath_common+0x80/0x98
 [<ffffffff81087fa4>] warn_slowpath_fmt+0x41/0x43
 [<ffffffff812a2608>] debug_print_object+0x7c/0x8d
 [<ffffffff812a2bca>] debug_check_no_obj_freed+0x95/0x1c3
 [<ffffffff8114cc69>] slab_free_hook+0x70/0x79
 [<ffffffff8114ea3e>] kfree+0x62/0xb7
 [<ffffffff8149f465>] netdev_release+0x39/0x3e
 [<ffffffff8136ad67>] device_release+0x52/0x8a
 [<ffffffff812937db>] kobject_release+0x121/0x158
 [<ffffffff81293612>] kobject_put+0x4c/0x50
 [<ffffffff8148f0d7>] netdev_run_todo+0x25c/0x27e

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Mar 28, 2013
[ Upstream commit 9cb6cb7 ]

The following script will produce a kernel oops:

    sudo ip netns add v
    sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
    sudo ip netns exec v ip link set lo up
    sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
    sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
    sudo ip netns exec v ip link set vxlan0 up
    sudo ip netns del v

where inspect by gdb:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 107]
    0xffffffffa0289e33 in ?? ()
    (gdb) bt
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    #1  vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
    #2  0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
    #3  0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
    #4  0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
    #5  0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
    #6  0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
    #7  0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
    #8  0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
    #9  0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
    #10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
    #11 <signal handler called>
    #12 0x0000000000000000 in ?? ()
    #13 0x0000000000000000 in ?? ()
    (gdb) fr 0
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    533		struct sock *sk = vn->sock->sk;
    (gdb) l
    528	static int vxlan_leave_group(struct net_device *dev)
    529	{
    530		struct vxlan_dev *vxlan = netdev_priv(dev);
    531		struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
    532		int err = 0;
    533		struct sock *sk = vn->sock->sk;
    534		struct ip_mreqn mreq = {
    535			.imr_multiaddr.s_addr	= vxlan->gaddr,
    536			.imr_ifindex		= vxlan->link,
    537		};
    (gdb) p vn->sock
    $4 = (struct socket *) 0x0

The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Jun 15, 2013
commit 34376a5 upstream.

The stop machine logic can lock up if all but one of the migration
threads make it through the disable-irq step and the one remaining
thread gets stuck in __do_softirq.  The reason __do_softirq can hang is
that it has a bail-out based on jiffies timeout, but in the lockup case,
jiffies itself is not incremented.

To work around this, re-add the max_restart counter in __do_irq and stop
processing irqs after 10 restarts.

Thanks to Tejun Heo and Rusty Russell and others for helping me track
this down.

This was introduced in 3.9 by commit c10d736 ("softirq: reduce
latencies").

It may be worth looking into ath9k to see if it has issues with its irq
handler at a later date.

The hang stack traces look something like this:

    ------------[ cut here ]------------
    WARNING: at kernel/watchdog.c:245 watchdog_overflow_callback+0x9c/0xa7()
    Watchdog detected hard LOCKUP on cpu 2
    Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
    Pid: 23, comm: migration/2 Tainted: G         C   3.9.4+ #11
    Call Trace:
     <NMI>   warn_slowpath_common+0x85/0x9f
      warn_slowpath_fmt+0x46/0x48
      watchdog_overflow_callback+0x9c/0xa7
      __perf_event_overflow+0x137/0x1cb
      perf_event_overflow+0x14/0x16
      intel_pmu_handle_irq+0x2dc/0x359
      perf_event_nmi_handler+0x19/0x1b
      nmi_handle+0x7f/0xc2
      do_nmi+0xbc/0x304
      end_repeat_nmi+0x1e/0x2e
     <<EOE>>
      cpu_stopper_thread+0xae/0x162
      smpboot_thread_fn+0x258/0x260
      kthread+0xc7/0xcf
      ret_from_fork+0x7c/0xb0
    ---[ end trace 4947dfa9b0a4cec3 ]---
    BUG: soft lockup - CPU#1 stuck for 22s! [migration/1:17]
    Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
    irq event stamp: 835637905
    hardirqs last  enabled at (835637904): __do_softirq+0x9f/0x257
    hardirqs last disabled at (835637905): apic_timer_interrupt+0x6d/0x80
    softirqs last  enabled at (5654720): __do_softirq+0x1ff/0x257
    softirqs last disabled at (5654725): irq_exit+0x5f/0xbb
    CPU 1
    Pid: 17, comm: migration/1 Tainted: G        WC   3.9.4+ #11 To be filled by O.E.M. To be filled by O.E.M./To be filled by O.E.M.
    RIP: tasklet_hi_action+0xf0/0xf0
    Process migration/1
    Call Trace:
     <IRQ>
      __do_softirq+0x117/0x257
      irq_exit+0x5f/0xbb
      smp_apic_timer_interrupt+0x8a/0x98
      apic_timer_interrupt+0x72/0x80
     <EOI>
      printk+0x4d/0x4f
      stop_machine_cpu_stop+0x22c/0x274
      cpu_stopper_thread+0xae/0x162
      smpboot_thread_fn+0x258/0x260
      kthread+0xc7/0xcf
      ret_from_fork+0x7c/0xb0

Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pekka Riikonen <priikone@iki.fi>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Jul 3, 2013
The stop machine logic can lock up if all but one of the migration
threads make it through the disable-irq step and the one remaining
thread gets stuck in __do_softirq.  The reason __do_softirq can hang is
that it has a bail-out based on jiffies timeout, but in the lockup case,
jiffies itself is not incremented.

To work around this, re-add the max_restart counter in __do_irq and stop
processing irqs after 10 restarts.

Thanks to Tejun Heo and Rusty Russell and others for helping me track
this down.

This was introduced in 3.9 by commit c10d736 ("softirq: reduce
latencies").

It may be worth looking into ath9k to see if it has issues with its irq
handler at a later date.

The hang stack traces look something like this:

    ------------[ cut here ]------------
    WARNING: at kernel/watchdog.c:245 watchdog_overflow_callback+0x9c/0xa7()
    Watchdog detected hard LOCKUP on cpu 2
    Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
    Pid: 23, comm: migration/2 Tainted: G         C   3.9.4+ #11
    Call Trace:
     <NMI>   warn_slowpath_common+0x85/0x9f
      warn_slowpath_fmt+0x46/0x48
      watchdog_overflow_callback+0x9c/0xa7
      __perf_event_overflow+0x137/0x1cb
      perf_event_overflow+0x14/0x16
      intel_pmu_handle_irq+0x2dc/0x359
      perf_event_nmi_handler+0x19/0x1b
      nmi_handle+0x7f/0xc2
      do_nmi+0xbc/0x304
      end_repeat_nmi+0x1e/0x2e
     <<EOE>>
      cpu_stopper_thread+0xae/0x162
      smpboot_thread_fn+0x258/0x260
      kthread+0xc7/0xcf
      ret_from_fork+0x7c/0xb0
    ---[ end trace 4947dfa9b0a4cec3 ]---
    BUG: soft lockup - CPU#1 stuck for 22s! [migration/1:17]
    Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
    irq event stamp: 835637905
    hardirqs last  enabled at (835637904): __do_softirq+0x9f/0x257
    hardirqs last disabled at (835637905): apic_timer_interrupt+0x6d/0x80
    softirqs last  enabled at (5654720): __do_softirq+0x1ff/0x257
    softirqs last disabled at (5654725): irq_exit+0x5f/0xbb
    CPU 1
    Pid: 17, comm: migration/1 Tainted: G        WC   3.9.4+ #11 To be filled by O.E.M. To be filled by O.E.M./To be filled by O.E.M.
    RIP: tasklet_hi_action+0xf0/0xf0
    Process migration/1
    Call Trace:
     <IRQ>
      __do_softirq+0x117/0x257
      irq_exit+0x5f/0xbb
      smp_apic_timer_interrupt+0x8a/0x98
      apic_timer_interrupt+0x72/0x80
     <EOI>
      printk+0x4d/0x4f
      stop_machine_cpu_stop+0x22c/0x274
      cpu_stopper_thread+0xae/0x162
      smpboot_thread_fn+0x258/0x260
      kthread+0xc7/0xcf
      ret_from_fork+0x7c/0xb0

Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pekka Riikonen <priikone@iki.fi>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
popcornmix pushed a commit that referenced this issue Aug 13, 2013
…s struct file

commit e4daf1f upstream.

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 #19 [ffff88062e365ee8] kthread at ffffffff81090886
 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------

Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Sep 4, 2013
…s struct file

The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
  - dentry_open
    - do_dentry_open
      - __get_file_write_access
        - get_write_access
          - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------

can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
  fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
  fi_access = {{
      counter = 0x1
    }, {
      counter = 0x0
    }},
...
------------------------------------------------------------

1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.

2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.

3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
     [exception RIP: fput+0x9]
     RIP: ffffffff81177fa9  RSP: ffff88062e365c90  RFLAGS: 00010282
     RAX: ffff880c2b3d99cc  RBX: ffff880c2b3d9978  RCX: 0000000000000002
     RDX: dead000000100101  RSI: 0000000000000001  RDI: ffffffffffffffe6
     RBP: ffff88062e365c90   R8: ffff88041fe797d8   R9: ffff88062e365d58
     R10: 0000000000000008  R11: 0000000000000000  R12: 0000000000000001
     R13: 0000000000000007  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
 #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
 #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
 #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
 #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
 #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
 #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
 #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
 #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
 #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
 #19 [ffff88062e365ee8] kthread at ffffffff81090886
 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------

Cc: stable@vger.kernel.org
Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
popcornmix pushed a commit that referenced this issue Nov 4, 2013
When booting secondary CPUs, announce_cpu() is called to show which cpu has
been brought up. For example:

[    0.402751] smpboot: Booting Node   0, Processors  #1 #2 #3 #4 #5 OK
[    0.525667] smpboot: Booting Node   1, Processors  #6 #7 #8 #9 #10 #11 OK
[    0.755592] smpboot: Booting Node   0, Processors  #12 #13 #14 #15 #16 #17 OK
[    0.890495] smpboot: Booting Node   1, Processors  #18 #19 #20 #21 #22 #23

But the last "OK" is lost, because 'nr_cpu_ids-1' represents the maximum
possible cpu id. It should use the maximum present cpu id in case not all
CPUs booted up.

Signed-off-by: Libin <huawei.libin@huawei.com>
Cc: <guohanjun@huawei.com>
Cc: <wangyijing@huawei.com>
Cc: <fenghua.yu@intel.com>
Cc: <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1378378676-18276-1-git-send-email-huawei.libin@huawei.com
[ tweaked the changelog, removed unnecessary line break, tweaked the format to align the fields vertically. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
popcornmix pushed a commit that referenced this issue Nov 4, 2013
When parsing lines from objdump a line containing source code starting
with a numeric label is mistaken for a line of disassembly starting with
a memory address.

Current validation fails to recognise that the "memory address" is out
of range and calculates an invalid offset which later causes this
segfault:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
    at util/annotate.c:631
631				hits += h->addr[offset++];
(gdb) bt
 #0  0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
    at util/annotate.c:631
 #1  0x00000000004d65e3 in annotate_browser__calc_percent (browser=0x7fffffffd130, evsel=0xa01da0) at ui/browsers/annotate.c:364
 #2  0x00000000004d7433 in annotate_browser__run (browser=0x7fffffffd130, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:672
 #3  0x00000000004d80c9 in symbol__tui_annotate (sym=0xc989a0, map=0xa02660, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:962
 #4  0x00000000004d7aa0 in hist_entry__tui_annotate (he=0xdf73f0, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:823
 #5  0x00000000004dd648 in perf_evsel__hists_browse (evsel=0xa01da0, nr_events=1, helpline=
    0x58b768 "For a higher level overview, try: perf report --sort comm,dso", ev_name=0xa02cd0 "cycles", left_exits=false, hbt=
    0x0, min_pcnt=0, env=0xa011e0) at ui/browsers/hists.c:1659
 #6  0x00000000004de372 in perf_evlist__tui_browse_hists (evlist=0xa01520, help=
    0x58b768 "For a higher level overview, try: perf report --sort comm,dso", hbt=0x0, min_pcnt=0, env=0xa011e0)
    at ui/browsers/hists.c:1950
 #7  0x000000000042cf6b in __cmd_report (rep=0x7fffffffd6c0) at builtin-report.c:581
 #8  0x000000000042e25d in cmd_report (argc=0, argv=0x7fffffffe4b0, prefix=0x0) at builtin-report.c:965
 #9  0x000000000041a0e1 in run_builtin (p=0x801548, argc=1, argv=0x7fffffffe4b0) at perf.c:319
 #10 0x000000000041a319 in handle_internal_command (argc=1, argv=0x7fffffffe4b0) at perf.c:376
 #11 0x000000000041a465 in run_argv (argcp=0x7fffffffe38c, argv=0x7fffffffe380) at perf.c:420
 #12 0x000000000041a707 in main (argc=1, argv=0x7fffffffe4b0) at perf.c:521

After the fix is applied the symbol can be annotated showing the
problematic line "1:      rep"

copy_user_generic_string  /usr/lib/debug/lib/modules/3.9.10-100.fc17.x86_64/vmlinux
             */
            ENTRY(copy_user_generic_string)
                    CFI_STARTPROC
                    ASM_STAC
                    andl %edx,%edx
              and    %edx,%edx
                    jz 4f
              je     37
                    cmpl $8,%edx
              cmp    $0x8,%edx
                    jb 2f           /* less than 8 bytes, go to byte copy loop */
              jb     33
                    ALIGN_DESTINATION
              mov    %edi,%ecx
              and    $0x7,%ecx
              je     28
              sub    $0x8,%ecx
              neg    %ecx
              sub    %ecx,%edx
        1a:   mov    (%rsi),%al
              mov    %al,(%rdi)
              inc    %rsi
              inc    %rdi
              dec    %ecx
              jne    1a
                    movl %edx,%ecx
        28:   mov    %edx,%ecx
                    shrl $3,%ecx
              shr    $0x3,%ecx
                    andl $7,%edx
              and    $0x7,%edx
            1:      rep
100.00        rep    movsq %ds:(%rsi),%es:(%rdi)
                    movsq
            2:      movl %edx,%ecx
        33:   mov    %edx,%ecx
            3:      rep
              rep    movsb %ds:(%rsi),%es:(%rdi)
                    movsb
            4:      xorl %eax,%eax
        37:   xor    %eax,%eax
              data32 xchg %ax,%ax
                    ASM_CLAC
                    ret
              retq

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1379009721-27667-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
popcornmix pushed a commit that referenced this issue Nov 22, 2013
commit 057db84 upstream.

Andrey reported the following report:

ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3
ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3)
Accessed by thread T13003:
  #0 ffffffff810dd2da (asan_report_error+0x32a/0x440)
  #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  #4 ffffffff812a1065 (__fput+0x155/0x360)
  #5 ffffffff812a12de (____fput+0x1e/0x30)
  #6 ffffffff8111708d (task_work_run+0x10d/0x140)
  #7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  #8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  #1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  #6 ffffffff8129b668 (finish_open+0x68/0xa0)
  #7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  #8 ffffffff812b7350 (path_openat+0x120/0xb50)
  #9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  #11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Shadow bytes around the buggy address:
  ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb
  ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap redzone:          fa
  Heap kmalloc redzone:  fb
  Freed heap region:     fd
  Shadow gap:            fe

The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;'

Although the crash happened in ftrace_regex_open() the real bug
occurred in trace_get_user() where there's an incrementation to
parser->idx without a check against the size. The way it is triggered
is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop
that reads the last character stores it and then breaks out because
there is no more characters. Then the last character is read to determine
what to do next, and the index is incremented without checking size.

Then the caller of trace_get_user() usually nulls out the last character
with a zero, but since the index is equal to the size, it writes a nul
character after the allocated space, which can corrupt memory.

Luckily, only root user has write access to this file.

Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Nov 22, 2013
commit 057db84 upstream.

Andrey reported the following report:

ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3
ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3)
Accessed by thread T13003:
  #0 ffffffff810dd2da (asan_report_error+0x32a/0x440)
  #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  #4 ffffffff812a1065 (__fput+0x155/0x360)
  #5 ffffffff812a12de (____fput+0x1e/0x30)
  #6 ffffffff8111708d (task_work_run+0x10d/0x140)
  #7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  #8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  #1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  #6 ffffffff8129b668 (finish_open+0x68/0xa0)
  #7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  #8 ffffffff812b7350 (path_openat+0x120/0xb50)
  #9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  #11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Shadow bytes around the buggy address:
  ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb
  ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap redzone:          fa
  Heap kmalloc redzone:  fb
  Freed heap region:     fd
  Shadow gap:            fe

The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;'

Although the crash happened in ftrace_regex_open() the real bug
occurred in trace_get_user() where there's an incrementation to
parser->idx without a check against the size. The way it is triggered
is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop
that reads the last character stores it and then breaks out because
there is no more characters. Then the last character is read to determine
what to do next, and the index is incremented without checking size.

Then the caller of trace_get_user() usually nulls out the last character
with a zero, but since the index is equal to the size, it writes a nul
character after the allocated space, which can corrupt memory.

Luckily, only root user has write access to this file.

Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
davet321 pushed a commit to davet321/rpi-linux that referenced this issue Nov 28, 2013
commit 057db84 upstream.

Andrey reported the following report:

ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3
ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3)
Accessed by thread T13003:
  #0 ffffffff810dd2da (asan_report_error+0x32a/0x440)
  raspberrypi#1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  raspberrypi#2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  raspberrypi#3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  raspberrypi#4 ffffffff812a1065 (__fput+0x155/0x360)
  raspberrypi#5 ffffffff812a12de (____fput+0x1e/0x30)
  raspberrypi#6 ffffffff8111708d (task_work_run+0x10d/0x140)
  raspberrypi#7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  raspberrypi#8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  raspberrypi#9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  raspberrypi#10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  raspberrypi#1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  raspberrypi#2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  raspberrypi#3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  raspberrypi#4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  raspberrypi#5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  raspberrypi#6 ffffffff8129b668 (finish_open+0x68/0xa0)
  raspberrypi#7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  raspberrypi#8 ffffffff812b7350 (path_openat+0x120/0xb50)
  raspberrypi#9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  raspberrypi#10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  raspberrypi#11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  raspberrypi#12 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Shadow bytes around the buggy address:
  ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb
  ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap redzone:          fa
  Heap kmalloc redzone:  fb
  Freed heap region:     fd
  Shadow gap:            fe

The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;'

Although the crash happened in ftrace_regex_open() the real bug
occurred in trace_get_user() where there's an incrementation to
parser->idx without a check against the size. The way it is triggered
is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop
that reads the last character stores it and then breaks out because
there is no more characters. Then the last character is read to determine
what to do next, and the index is incremented without checking size.

Then the caller of trace_get_user() usually nulls out the last character
with a zero, but since the index is equal to the size, it writes a nul
character after the allocated space, which can corrupt memory.

Luckily, only root user has write access to this file.

Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Jun 7, 2014
commit 561a4fe upstream.

As trace event triggers are now part of the mainline kernel, I added
my trace event trigger tests to my test suite I run on all my kernels.
Now these tests get run under different config options, and one of
those options is CONFIG_PROVE_RCU, which checks under lockdep that
the rcu locking primitives are being used correctly. This triggered
the following splat:

===============================
[ INFO: suspicious RCU usage. ]
3.15.0-rc2-test+ #11 Not tainted
-------------------------------
kernel/trace/trace_events_trigger.c:80 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
4 locks held by swapper/1/0:
 #0:  ((&(&j_cdbs->work)->timer)){..-...}, at: [<ffffffff8104d2cc>] call_timer_fn+0x5/0x1be
 #1:  (&(&pool->lock)->rlock){-.-...}, at: [<ffffffff81059856>] __queue_work+0x140/0x283
 #2:  (&p->pi_lock){-.-.-.}, at: [<ffffffff8106e961>] try_to_wake_up+0x2e/0x1e8
 #3:  (&rq->lock){-.-.-.}, at: [<ffffffff8106ead3>] try_to_wake_up+0x1a0/0x1e8

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc2-test+ #11
Hardware name:                  /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
 0000000000000001 ffff88007e083b98 ffffffff819f53a5 0000000000000006
 ffff88007b0942c0 ffff88007e083bc8 ffffffff81081307 ffff88007ad96d20
 0000000000000000 ffff88007af2d840 ffff88007b2e701c ffff88007e083c18
Call Trace:
 <IRQ>  [<ffffffff819f53a5>] dump_stack+0x4f/0x7c
 [<ffffffff81081307>] lockdep_rcu_suspicious+0x107/0x110
 [<ffffffff810ee51c>] event_triggers_call+0x99/0x108
 [<ffffffff810e8174>] ftrace_event_buffer_commit+0x42/0xa4
 [<ffffffff8106aadc>] ftrace_raw_event_sched_wakeup_template+0x71/0x7c
 [<ffffffff8106bcbf>] ttwu_do_wakeup+0x7f/0xff
 [<ffffffff8106bd9b>] ttwu_do_activate.constprop.126+0x5c/0x61
 [<ffffffff8106eadf>] try_to_wake_up+0x1ac/0x1e8
 [<ffffffff8106eb77>] wake_up_process+0x36/0x3b
 [<ffffffff810575cc>] wake_up_worker+0x24/0x26
 [<ffffffff810578bc>] insert_work+0x5c/0x65
 [<ffffffff81059982>] __queue_work+0x26c/0x283
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff810599b7>] delayed_work_timer_fn+0x1e/0x20
 [<ffffffff8104d3a6>] call_timer_fn+0xdf/0x1be^M
 [<ffffffff8104d2cc>] ? call_timer_fn+0x5/0x1be
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff8104d823>] run_timer_softirq+0x1a4/0x22f^M
 [<ffffffff8104696d>] __do_softirq+0x17b/0x31b^M
 [<ffffffff81046d03>] irq_exit+0x42/0x97
 [<ffffffff81a08db6>] smp_apic_timer_interrupt+0x37/0x44
 [<ffffffff81a07a2f>] apic_timer_interrupt+0x6f/0x80
 <EOI>  [<ffffffff8100a5d8>] ? default_idle+0x21/0x32
 [<ffffffff8100a5d6>] ? default_idle+0x1f/0x32
 [<ffffffff8100ac10>] arch_cpu_idle+0xf/0x11
 [<ffffffff8107b3a4>] cpu_startup_entry+0x1a3/0x213
 [<ffffffff8102a23c>] start_secondary+0x212/0x219

The cause is that the triggers are protected by rcu_read_lock_sched() but
the data is dereferenced with rcu_dereference() which expects it to
be protected with rcu_read_lock(). The proper reference should be
rcu_dereference_sched().

Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Jun 8, 2014
Commit "d9e7972 hwrng: add randomness to system from rng sources"
exposed a bug in the bcm2835-rng driver resulting in boot failure
on Raspberry Pi due to the following oops:

[   28.261523] BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1]
[   28.271058]
[   28.275958] CPU: 0 PID: 1 Comm: swapper Not tainted 3.14.0+ #11
[   28.285374] task: db480000 ti: db484000 task.ti: db484000
[   28.294279] PC is at bcm2835_rng_read+0x28/0x48
[   28.302276] LR is at hwrng_register+0x1a8/0x238
.
.
.

The RNG h/w is not completely initialized and enabled before
hwrng_register() is called and so the bcm2835_rng_read() fails.
Fix this by making the warmup/enable writes before registering
the RNG source with the hwrng core.

Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
popcornmix pushed a commit that referenced this issue Jun 8, 2014
When the Ethernet interface is brought down during high Ethernet traffic,
then cpsw creates the following warn dump. When cpdma has already processed
the packet then the status will be greater than 0, so the cpsw_rx_handler
considers that the interface is up and try to resubmit one more rx buffer
to cpdma which fails as the DMA is in teardown process. This can be avoided
by checking the interface state and then process the received packet, if the
interface is down just discard and free the skb and return.

[ 2823.104591] WARNING: CPU: 0 PID: 1823 at drivers/net/ethernet/ti/cpsw.c:711 cpsw_rx_handler+0x148/0x164()
[ 2823.114654] Modules linked in:
[ 2823.117872] CPU: 0 PID: 1823 Comm: ifconfig Tainted: G        W     3.14.0-11992-gf34c4a3 #11
[ 2823.126860] [<c0014b5c>] (unwind_backtrace) from [<c00117e4>] (show_stack+0x10/0x14)
[ 2823.135030] [<c00117e4>] (show_stack) from [<c0533a9c>] (dump_stack+0x80/0x9c)
[ 2823.142619] [<c0533a9c>] (dump_stack) from [<c003f0e0>] (warn_slowpath_common+0x6c/0x90)
[ 2823.151141] [<c003f0e0>] (warn_slowpath_common) from [<c003f120>] (warn_slowpath_null+0x1c/0x24)
[ 2823.160336] [<c003f120>] (warn_slowpath_null) from [<c03caeb0>] (cpsw_rx_handler+0x148/0x164)
[ 2823.169314] [<c03caeb0>] (cpsw_rx_handler) from [<c03c730c>] (__cpdma_chan_free+0x90/0xa8)
[ 2823.178028] [<c03c730c>] (__cpdma_chan_free) from [<c03c7418>] (__cpdma_chan_process+0xf4/0x134)
[ 2823.187279] [<c03c7418>] (__cpdma_chan_process) from [<c03c7560>] (cpdma_chan_stop+0xb4/0x17c)
[ 2823.196349] [<c03c7560>] (cpdma_chan_stop) from [<c03c766c>] (cpdma_ctlr_stop+0x44/0x9c)
[ 2823.204872] [<c03c766c>] (cpdma_ctlr_stop) from [<c03cb708>] (cpsw_ndo_stop+0x154/0x188)
[ 2823.213321] [<c03cb708>] (cpsw_ndo_stop) from [<c046f0ec>] (__dev_close_many+0x84/0xc8)
[ 2823.221761] [<c046f0ec>] (__dev_close_many) from [<c046f158>] (__dev_close+0x28/0x3c)
[ 2823.230012] [<c046f158>] (__dev_close) from [<c0474ca8>] (__dev_change_flags+0x88/0x160)
[ 2823.238483] [<c0474ca8>] (__dev_change_flags) from [<c0474da0>] (dev_change_flags+0x18/0x48)
[ 2823.247316] [<c0474da0>] (dev_change_flags) from [<c04d12c4>] (devinet_ioctl+0x61c/0x6e0)
[ 2823.255884] [<c04d12c4>] (devinet_ioctl) from [<c045c660>] (sock_ioctl+0x68/0x2a4)
[ 2823.263789] [<c045c660>] (sock_ioctl) from [<c0125fe4>] (do_vfs_ioctl+0x78/0x61c)
[ 2823.271629] [<c0125fe4>] (do_vfs_ioctl) from [<c01265ec>] (SyS_ioctl+0x64/0x74)
[ 2823.279284] [<c01265ec>] (SyS_ioctl) from [<c000e580>] (ret_fast_syscall+0x0/0x48)

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
popcornmix pushed a commit that referenced this issue Jun 8, 2014
As trace event triggers are now part of the mainline kernel, I added
my trace event trigger tests to my test suite I run on all my kernels.
Now these tests get run under different config options, and one of
those options is CONFIG_PROVE_RCU, which checks under lockdep that
the rcu locking primitives are being used correctly. This triggered
the following splat:

===============================
[ INFO: suspicious RCU usage. ]
3.15.0-rc2-test+ #11 Not tainted
-------------------------------
kernel/trace/trace_events_trigger.c:80 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
4 locks held by swapper/1/0:
 #0:  ((&(&j_cdbs->work)->timer)){..-...}, at: [<ffffffff8104d2cc>] call_timer_fn+0x5/0x1be
 #1:  (&(&pool->lock)->rlock){-.-...}, at: [<ffffffff81059856>] __queue_work+0x140/0x283
 #2:  (&p->pi_lock){-.-.-.}, at: [<ffffffff8106e961>] try_to_wake_up+0x2e/0x1e8
 #3:  (&rq->lock){-.-.-.}, at: [<ffffffff8106ead3>] try_to_wake_up+0x1a0/0x1e8

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc2-test+ #11
Hardware name:                  /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
 0000000000000001 ffff88007e083b98 ffffffff819f53a5 0000000000000006
 ffff88007b0942c0 ffff88007e083bc8 ffffffff81081307 ffff88007ad96d20
 0000000000000000 ffff88007af2d840 ffff88007b2e701c ffff88007e083c18
Call Trace:
 <IRQ>  [<ffffffff819f53a5>] dump_stack+0x4f/0x7c
 [<ffffffff81081307>] lockdep_rcu_suspicious+0x107/0x110
 [<ffffffff810ee51c>] event_triggers_call+0x99/0x108
 [<ffffffff810e8174>] ftrace_event_buffer_commit+0x42/0xa4
 [<ffffffff8106aadc>] ftrace_raw_event_sched_wakeup_template+0x71/0x7c
 [<ffffffff8106bcbf>] ttwu_do_wakeup+0x7f/0xff
 [<ffffffff8106bd9b>] ttwu_do_activate.constprop.126+0x5c/0x61
 [<ffffffff8106eadf>] try_to_wake_up+0x1ac/0x1e8
 [<ffffffff8106eb77>] wake_up_process+0x36/0x3b
 [<ffffffff810575cc>] wake_up_worker+0x24/0x26
 [<ffffffff810578bc>] insert_work+0x5c/0x65
 [<ffffffff81059982>] __queue_work+0x26c/0x283
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff810599b7>] delayed_work_timer_fn+0x1e/0x20
 [<ffffffff8104d3a6>] call_timer_fn+0xdf/0x1be^M
 [<ffffffff8104d2cc>] ? call_timer_fn+0x5/0x1be
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff8104d823>] run_timer_softirq+0x1a4/0x22f^M
 [<ffffffff8104696d>] __do_softirq+0x17b/0x31b^M
 [<ffffffff81046d03>] irq_exit+0x42/0x97
 [<ffffffff81a08db6>] smp_apic_timer_interrupt+0x37/0x44
 [<ffffffff81a07a2f>] apic_timer_interrupt+0x6f/0x80
 <EOI>  [<ffffffff8100a5d8>] ? default_idle+0x21/0x32
 [<ffffffff8100a5d6>] ? default_idle+0x1f/0x32
 [<ffffffff8100ac10>] arch_cpu_idle+0xf/0x11
 [<ffffffff8107b3a4>] cpu_startup_entry+0x1a3/0x213
 [<ffffffff8102a23c>] start_secondary+0x212/0x219

The cause is that the triggers are protected by rcu_read_lock_sched() but
the data is dereferenced with rcu_dereference() which expects it to
be protected with rcu_read_lock(). The proper reference should be
rcu_dereference_sched().

Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
popcornmix pushed a commit that referenced this issue Jun 8, 2014
This interface is unusable, as the cdc-wdm character device doesn't reply to
any QMI command. Also, the out-of-tree Sierra Wireless GobiNet driver fully
skips it.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
popcornmix pushed a commit that referenced this issue Jun 8, 2014
Pull networking fixes from David Miller:

 1) Unbreak zebra and other netlink apps, from Eric W Biederman.

 2) Some new qmi_wwan device IDs, from Aleksander Morgado.

 3) Fix info leak in DCB netlink handler of qlcnic driver, from Dan
    Carpenter.

 4) inet_getid() and ipv6_select_ident() do not generate monotonically
    increasing ID numbers, fix from Eric Dumazet.

 5) Fix memory leak in __sk_prepare_filter(), from Leon Yu.

 6) Netlink leftover bytes warning message is user triggerable, rate
    limit it.  From Michal Schmidt.

 7) Fix non-linear SKB panic in ipvs, from Peter Christensen.

 8) Congestion window undo needs to be performed even if only never
    retransmitted data is SACK'd, fix from Yuching Cheng.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (24 commits)
  net: filter: fix possible memory leak in __sk_prepare_filter()
  net: ec_bhf: Add runtime dependencies
  tcp: fix cwnd undo on DSACK in F-RTO
  netlink: Only check file credentials for implicit destinations
  ipheth: Add support for iPad 2 and iPad 3
  team: fix mtu setting
  net: fix inet_getid() and ipv6_select_ident() bugs
  net: qmi_wwan: interface #11 in Sierra Wireless MC73xx is not QMI
  net: qmi_wwan: add additional Sierra Wireless QMI devices
  bridge: Prevent insertion of FDB entry with disallowed vlan
  netlink: rate-limit leftover bytes warning and print process name
  bridge: notify user space after fdb update
  net: qmi_wwan: add Netgear AirCard 341U
  net: fix wrong mac_len calculation for vlans
  batman-adv: fix NULL pointer dereferences
  net/mlx4_core: Reset RoCE VF gids when guest driver goes down
  emac: aggregation of v1-2 PLB errors for IER register
  emac: add missing support of 10mbit in emac/rgmii
  can: only rename enabled led triggers when changing the netdev name
  ipvs: Fix panic due to non-linear skb
  ...
popcornmix pushed a commit that referenced this issue Jul 1, 2024
The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
popcornmix pushed a commit that referenced this issue Jul 8, 2024
commit be346c1 upstream.

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Jul 8, 2024
commit be346c1 upstream.

The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pelwell pushed a commit that referenced this issue Aug 2, 2024
[ Upstream commit 769e6a1 ]

ui_browser__show() is capturing the input title that is stack allocated
memory in hist_browser__run().

Avoid a use after return by strdup-ing the string.

Committer notes:

Further explanation from Ian Rogers:

My command line using tui is:
$ sudo bash -c 'rm /tmp/asan.log*; export
ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a
sleep 1; /tmp/perf/perf mem report'
I then go to the perf annotate view and quit. This triggers the asan
error (from the log file):
```
==1254591==ERROR: AddressSanitizer: stack-use-after-return on address
0x7f2813331920 at pc 0x7f28180
65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10
READ of size 80 at 0x7f2813331920 thread T0
    #0 0x7f2818065990 in __interceptor_strlen
../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461
    #1 0x7f2817698251 in SLsmg_write_wrapped_string
(/lib/x86_64-linux-gnu/libslang.so.2+0x98251)
    #2 0x7f28176984b9 in SLsmg_write_nstring
(/lib/x86_64-linux-gnu/libslang.so.2+0x984b9)
    #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60
    #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266
    #5 0x55c94045c776 in ui_browser__show ui/browser.c:288
    #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206
    #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458
    #8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412
    #9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527
    #10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613
    #11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661
    #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671
    #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141
    #14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805
    #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374
    #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516
    #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350
    #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403
    #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447
    #20 0x55c9400e53ad in main tools/perf/perf.c:561
    #21 0x7f28170456c9 in __libc_start_call_main
../sysdeps/nptl/libc_start_call_main.h:58
    #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360
    #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId:
84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93)

Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame
    #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746

  This frame has 1 object(s):
    [32, 192) 'title' (line 747) <== Memory access at offset 32 is
inside this variable
HINT: this may be a false positive if your program uses some custom
stack unwind mechanism, swapcontext or vfork
```
hist_browser__run isn't on the stack so the asan error looks legit.
There's no clean init/exit on struct ui_browser so I may be trading a
use-after-return for a memory leak, but that seems look a good trade
anyway.

Fixes: 05e8b08 ("perf ui browser: Stop using 'self'")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Li Dong <lidong@vivo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240507183545.1236093-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Aug 5, 2024
[ Upstream commit eef0532 ]

Run bpf_tcp_ca selftests (./test_progs -t bpf_tcp_ca) on a Loongarch
platform, some "Segmentation fault" errors occur:

'''
 test_dctcp:PASS:bpf_dctcp__open_and_load 0 nsec
 test_dctcp:FAIL:bpf_map__attach_struct_ops unexpected error: -524
 #29/1    bpf_tcp_ca/dctcp:FAIL
 test_cubic:PASS:bpf_cubic__open_and_load 0 nsec
 test_cubic:FAIL:bpf_map__attach_struct_ops unexpected error: -524
 #29/2    bpf_tcp_ca/cubic:FAIL
 test_dctcp_fallback:PASS:dctcp_skel 0 nsec
 test_dctcp_fallback:PASS:bpf_dctcp__load 0 nsec
 test_dctcp_fallback:FAIL:dctcp link unexpected error: -524
 #29/4    bpf_tcp_ca/dctcp_fallback:FAIL
 test_write_sk_pacing:PASS:open_and_load 0 nsec
 test_write_sk_pacing:FAIL:attach_struct_ops unexpected error: -524
 #29/6    bpf_tcp_ca/write_sk_pacing:FAIL
 test_update_ca:PASS:open 0 nsec
 test_update_ca:FAIL:attach_struct_ops unexpected error: -524
 settcpca:FAIL:setsockopt unexpected setsockopt: \
					actual -1 == expected -1
 (network_helpers.c:99: errno: No such file or directory) \
					Failed to call post_socket_cb
 start_test:FAIL:start_server_str unexpected start_server_str: \
					actual -1 == expected -1
 test_update_ca:FAIL:ca1_ca1_cnt unexpected ca1_ca1_cnt: \
					actual 0 <= expected 0
 #29/9    bpf_tcp_ca/update_ca:FAIL
 #29      bpf_tcp_ca:FAIL
 Caught signal #11!
 Stack trace:
 ./test_progs(crash_handler+0x28)[0x5555567ed91c]
 linux-vdso.so.1(__vdso_rt_sigreturn+0x0)[0x7ffffee408b0]
 ./test_progs(bpf_link__update_map+0x80)[0x555556824a78]
 ./test_progs(+0x94d68)[0x5555564c4d68]
 ./test_progs(test_bpf_tcp_ca+0xe8)[0x5555564c6a88]
 ./test_progs(+0x3bde54)[0x5555567ede54]
 ./test_progs(main+0x61c)[0x5555567efd54]
 /usr/lib64/libc.so.6(+0x22208)[0x7ffff2aaa208]
 /usr/lib64/libc.so.6(__libc_start_main+0xac)[0x7ffff2aaa30c]
 ./test_progs(_start+0x48)[0x55555646bca8]
 Segmentation fault
'''

This is because BPF trampoline is not implemented on Loongarch yet,
"link" returned by bpf_map__attach_struct_ops() is NULL. test_progs
crashs when this NULL link passes to bpf_link__update_map(). This
patch adds NULL checks for all links in bpf_tcp_ca to fix these errors.
If "link" is NULL, goto the newly added label "out" to destroy the skel.

v2:
 - use "goto out" instead of "return" as Eduard suggested.

Fixes: 06da9f3 ("selftests/bpf: Test switching TCP Congestion Control algorithms.")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/b4c841492bd4ed97964e4e61e92827ce51bf1dc9.1720615848.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Aug 5, 2024
[ Upstream commit eef0532 ]

Run bpf_tcp_ca selftests (./test_progs -t bpf_tcp_ca) on a Loongarch
platform, some "Segmentation fault" errors occur:

'''
 test_dctcp:PASS:bpf_dctcp__open_and_load 0 nsec
 test_dctcp:FAIL:bpf_map__attach_struct_ops unexpected error: -524
 #29/1    bpf_tcp_ca/dctcp:FAIL
 test_cubic:PASS:bpf_cubic__open_and_load 0 nsec
 test_cubic:FAIL:bpf_map__attach_struct_ops unexpected error: -524
 #29/2    bpf_tcp_ca/cubic:FAIL
 test_dctcp_fallback:PASS:dctcp_skel 0 nsec
 test_dctcp_fallback:PASS:bpf_dctcp__load 0 nsec
 test_dctcp_fallback:FAIL:dctcp link unexpected error: -524
 #29/4    bpf_tcp_ca/dctcp_fallback:FAIL
 test_write_sk_pacing:PASS:open_and_load 0 nsec
 test_write_sk_pacing:FAIL:attach_struct_ops unexpected error: -524
 #29/6    bpf_tcp_ca/write_sk_pacing:FAIL
 test_update_ca:PASS:open 0 nsec
 test_update_ca:FAIL:attach_struct_ops unexpected error: -524
 settcpca:FAIL:setsockopt unexpected setsockopt: \
					actual -1 == expected -1
 (network_helpers.c:99: errno: No such file or directory) \
					Failed to call post_socket_cb
 start_test:FAIL:start_server_str unexpected start_server_str: \
					actual -1 == expected -1
 test_update_ca:FAIL:ca1_ca1_cnt unexpected ca1_ca1_cnt: \
					actual 0 <= expected 0
 #29/9    bpf_tcp_ca/update_ca:FAIL
 #29      bpf_tcp_ca:FAIL
 Caught signal #11!
 Stack trace:
 ./test_progs(crash_handler+0x28)[0x5555567ed91c]
 linux-vdso.so.1(__vdso_rt_sigreturn+0x0)[0x7ffffee408b0]
 ./test_progs(bpf_link__update_map+0x80)[0x555556824a78]
 ./test_progs(+0x94d68)[0x5555564c4d68]
 ./test_progs(test_bpf_tcp_ca+0xe8)[0x5555564c6a88]
 ./test_progs(+0x3bde54)[0x5555567ede54]
 ./test_progs(main+0x61c)[0x5555567efd54]
 /usr/lib64/libc.so.6(+0x22208)[0x7ffff2aaa208]
 /usr/lib64/libc.so.6(__libc_start_main+0xac)[0x7ffff2aaa30c]
 ./test_progs(_start+0x48)[0x55555646bca8]
 Segmentation fault
'''

This is because BPF trampoline is not implemented on Loongarch yet,
"link" returned by bpf_map__attach_struct_ops() is NULL. test_progs
crashs when this NULL link passes to bpf_link__update_map(). This
patch adds NULL checks for all links in bpf_tcp_ca to fix these errors.
If "link" is NULL, goto the newly added label "out" to destroy the skel.

v2:
 - use "goto out" instead of "return" as Eduard suggested.

Fixes: 06da9f3 ("selftests/bpf: Test switching TCP Congestion Control algorithms.")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/b4c841492bd4ed97964e4e61e92827ce51bf1dc9.1720615848.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Aug 27, 2024
Remove the dma_unmap_page_attrs() call in the driver's XDP_REDIRECT
code path.  This should have been removed when we let the page pool
handle the DMA mapping.  This bug causes the warning:

WARNING: CPU: 7 PID: 59 at drivers/iommu/dma-iommu.c:1198 iommu_dma_unmap_page+0xd5/0x100
CPU: 7 PID: 59 Comm: ksoftirqd/7 Tainted: G        W          6.8.0-1010-gcp #11-Ubuntu
Hardware name: Dell Inc. PowerEdge R7525/0PYVT1, BIOS 2.15.2 04/02/2024
RIP: 0010:iommu_dma_unmap_page+0xd5/0x100
Code: 89 ee 48 89 df e8 cb f2 69 ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9 31 f6 31 ff 45 31 c0 e9 ab 17 71 00 <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9
RSP: 0018:ffffab1fc0597a48 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99ff838280c8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffab1fc0597a78 R08: 0000000000000002 R09: ffffab1fc0597c1c
R10: ffffab1fc0597cd3 R11: ffff99ffe375acd8 R12: 00000000e65b9000
R13: 0000000000000050 R14: 0000000000001000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff9a06efb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565c34c37210 CR3: 00000005c7e3e000 CR4: 0000000000350ef0
? show_regs+0x6d/0x80
? __warn+0x89/0x150
? iommu_dma_unmap_page+0xd5/0x100
? report_bug+0x16a/0x190
? handle_bug+0x51/0xa0
? exc_invalid_op+0x18/0x80
? iommu_dma_unmap_page+0xd5/0x100
? iommu_dma_unmap_page+0x35/0x100
dma_unmap_page_attrs+0x55/0x220
? bpf_prog_4d7e87c0d30db711_xdp_dispatcher+0x64/0x9f
bnxt_rx_xdp+0x237/0x520 [bnxt_en]
bnxt_rx_pkt+0x640/0xdd0 [bnxt_en]
__bnxt_poll_work+0x1a1/0x3d0 [bnxt_en]
bnxt_poll+0xaa/0x1e0 [bnxt_en]
__napi_poll+0x33/0x1e0
net_rx_action+0x18a/0x2f0

Fixes: 578fcfd ("bnxt_en: Let the page pool manage the DMA mapping")
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20240820203415.168178-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
popcornmix pushed a commit that referenced this issue Aug 30, 2024
[ Upstream commit 8baeef7 ]

Remove the dma_unmap_page_attrs() call in the driver's XDP_REDIRECT
code path.  This should have been removed when we let the page pool
handle the DMA mapping.  This bug causes the warning:

WARNING: CPU: 7 PID: 59 at drivers/iommu/dma-iommu.c:1198 iommu_dma_unmap_page+0xd5/0x100
CPU: 7 PID: 59 Comm: ksoftirqd/7 Tainted: G        W          6.8.0-1010-gcp #11-Ubuntu
Hardware name: Dell Inc. PowerEdge R7525/0PYVT1, BIOS 2.15.2 04/02/2024
RIP: 0010:iommu_dma_unmap_page+0xd5/0x100
Code: 89 ee 48 89 df e8 cb f2 69 ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9 31 f6 31 ff 45 31 c0 e9 ab 17 71 00 <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9
RSP: 0018:ffffab1fc0597a48 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99ff838280c8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffab1fc0597a78 R08: 0000000000000002 R09: ffffab1fc0597c1c
R10: ffffab1fc0597cd3 R11: ffff99ffe375acd8 R12: 00000000e65b9000
R13: 0000000000000050 R14: 0000000000001000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff9a06efb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565c34c37210 CR3: 00000005c7e3e000 CR4: 0000000000350ef0
? show_regs+0x6d/0x80
? __warn+0x89/0x150
? iommu_dma_unmap_page+0xd5/0x100
? report_bug+0x16a/0x190
? handle_bug+0x51/0xa0
? exc_invalid_op+0x18/0x80
? iommu_dma_unmap_page+0xd5/0x100
? iommu_dma_unmap_page+0x35/0x100
dma_unmap_page_attrs+0x55/0x220
? bpf_prog_4d7e87c0d30db711_xdp_dispatcher+0x64/0x9f
bnxt_rx_xdp+0x237/0x520 [bnxt_en]
bnxt_rx_pkt+0x640/0xdd0 [bnxt_en]
__bnxt_poll_work+0x1a1/0x3d0 [bnxt_en]
bnxt_poll+0xaa/0x1e0 [bnxt_en]
__napi_poll+0x33/0x1e0
net_rx_action+0x18a/0x2f0

Fixes: 578fcfd ("bnxt_en: Let the page pool manage the DMA mapping")
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20240820203415.168178-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Sep 2, 2024
A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ncopa pushed a commit to ncopa/linux that referenced this issue Sep 4, 2024
[ Upstream commit 8baeef7 ]

Remove the dma_unmap_page_attrs() call in the driver's XDP_REDIRECT
code path.  This should have been removed when we let the page pool
handle the DMA mapping.  This bug causes the warning:

WARNING: CPU: 7 PID: 59 at drivers/iommu/dma-iommu.c:1198 iommu_dma_unmap_page+0xd5/0x100
CPU: 7 PID: 59 Comm: ksoftirqd/7 Tainted: G        W          6.8.0-1010-gcp raspberrypi#11-Ubuntu
Hardware name: Dell Inc. PowerEdge R7525/0PYVT1, BIOS 2.15.2 04/02/2024
RIP: 0010:iommu_dma_unmap_page+0xd5/0x100
Code: 89 ee 48 89 df e8 cb f2 69 ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9 31 f6 31 ff 45 31 c0 e9 ab 17 71 00 <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 c9
RSP: 0018:ffffab1fc0597a48 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99ff838280c8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffab1fc0597a78 R08: 0000000000000002 R09: ffffab1fc0597c1c
R10: ffffab1fc0597cd3 R11: ffff99ffe375acd8 R12: 00000000e65b9000
R13: 0000000000000050 R14: 0000000000001000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff9a06efb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565c34c37210 CR3: 00000005c7e3e000 CR4: 0000000000350ef0
? show_regs+0x6d/0x80
? __warn+0x89/0x150
? iommu_dma_unmap_page+0xd5/0x100
? report_bug+0x16a/0x190
? handle_bug+0x51/0xa0
? exc_invalid_op+0x18/0x80
? iommu_dma_unmap_page+0xd5/0x100
? iommu_dma_unmap_page+0x35/0x100
dma_unmap_page_attrs+0x55/0x220
? bpf_prog_4d7e87c0d30db711_xdp_dispatcher+0x64/0x9f
bnxt_rx_xdp+0x237/0x520 [bnxt_en]
bnxt_rx_pkt+0x640/0xdd0 [bnxt_en]
__bnxt_poll_work+0x1a1/0x3d0 [bnxt_en]
bnxt_poll+0xaa/0x1e0 [bnxt_en]
__napi_poll+0x33/0x1e0
net_rx_action+0x18a/0x2f0

Fixes: 578fcfd ("bnxt_en: Let the page pool manage the DMA mapping")
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20240820203415.168178-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ncopa pushed a commit to ncopa/linux that referenced this issue Sep 4, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  raspberrypi#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  raspberrypi#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 raspberrypi#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 raspberrypi#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 raspberrypi#12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 raspberrypi#13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 raspberrypi#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 raspberrypi#15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 raspberrypi#16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 raspberrypi#17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Sep 6, 2024
[ Upstream commit a699781 ]

A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Oct 10, 2024
commit 23dfdb5 upstream.

The following kernel trace can be triggered with fstest generic/629 when
executed against a filesystem with fast-commit feature enabled:

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 866 Comm: mount Not tainted 6.10.0+ #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x66/0x90
 register_lock_class+0x759/0x7d0
 __lock_acquire+0x85/0x2630
 ? __find_get_block+0xb4/0x380
 lock_acquire+0xd1/0x2d0
 ? __ext4_journal_get_write_access+0xd5/0x160
 _raw_spin_lock+0x33/0x40
 ? __ext4_journal_get_write_access+0xd5/0x160
 __ext4_journal_get_write_access+0xd5/0x160
 ext4_reserve_inode_write+0x61/0xb0
 __ext4_mark_inode_dirty+0x79/0x270
 ? ext4_ext_replay_set_iblocks+0x2f8/0x450
 ext4_ext_replay_set_iblocks+0x330/0x450
 ext4_fc_replay+0x14c8/0x1540
 ? jread+0x88/0x2e0
 ? rcu_is_watching+0x11/0x40
 do_one_pass+0x447/0xd00
 jbd2_journal_recover+0x139/0x1b0
 jbd2_journal_load+0x96/0x390
 ext4_load_and_init_journal+0x253/0xd40
 ext4_fill_super+0x2cc6/0x3180
...

In the replay path there's an attempt to lock sbi->s_bdev_wb_lock in
function ext4_check_bdev_write_error().  Unfortunately, at this point this
spinlock has not been initialized yet.  Moving it's initialization to an
earlier point in __ext4_fill_super() fixes this splat.

Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://patch.msgid.link/20240718094356.7863-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Oct 10, 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>
popcornmix pushed a commit that referenced this issue Oct 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>
popcornmix pushed a commit that referenced this issue Oct 10, 2024
commit 23dfdb5 upstream.

The following kernel trace can be triggered with fstest generic/629 when
executed against a filesystem with fast-commit feature enabled:

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 866 Comm: mount Not tainted 6.10.0+ #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x66/0x90
 register_lock_class+0x759/0x7d0
 __lock_acquire+0x85/0x2630
 ? __find_get_block+0xb4/0x380
 lock_acquire+0xd1/0x2d0
 ? __ext4_journal_get_write_access+0xd5/0x160
 _raw_spin_lock+0x33/0x40
 ? __ext4_journal_get_write_access+0xd5/0x160
 __ext4_journal_get_write_access+0xd5/0x160
 ext4_reserve_inode_write+0x61/0xb0
 __ext4_mark_inode_dirty+0x79/0x270
 ? ext4_ext_replay_set_iblocks+0x2f8/0x450
 ext4_ext_replay_set_iblocks+0x330/0x450
 ext4_fc_replay+0x14c8/0x1540
 ? jread+0x88/0x2e0
 ? rcu_is_watching+0x11/0x40
 do_one_pass+0x447/0xd00
 jbd2_journal_recover+0x139/0x1b0
 jbd2_journal_load+0x96/0x390
 ext4_load_and_init_journal+0x253/0xd40
 ext4_fill_super+0x2cc6/0x3180
...

In the replay path there's an attempt to lock sbi->s_bdev_wb_lock in
function ext4_check_bdev_write_error().  Unfortunately, at this point this
spinlock has not been initialized yet.  Moving it's initialization to an
earlier point in __ext4_fill_super() fixes this splat.

Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://patch.msgid.link/20240718094356.7863-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Oct 10, 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>
popcornmix pushed a commit that referenced this issue Oct 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>
popcornmix pushed a commit that referenced this issue Oct 10, 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>
popcornmix pushed a commit that referenced this issue Oct 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>
popcornmix pushed a commit that referenced this issue Oct 21, 2024
We're seeing crashes from rq_qos_wake_function that look like this:

  BUG: unable to handle page fault for address: ffffafe180a40084
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0
  Oops: Oops: 0002 [#1] PREEMPT SMP PTI
  CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 #11
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40
  Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00
  RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084
  RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011
  R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002
  R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003
  FS:  0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   <IRQ>
   try_to_wake_up+0x5a/0x6a0
   rq_qos_wake_function+0x71/0x80
   __wake_up_common+0x75/0xa0
   __wake_up+0x36/0x60
   scale_up.part.0+0x50/0x110
   wb_timer_fn+0x227/0x450
   ...

So rq_qos_wake_function() calls wake_up_process(data->task), which calls
try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock).

p comes from data->task, and data comes from the waitqueue entry, which
is stored on the waiter's stack in rq_qos_wait(). Analyzing the core
dump with drgn, I found that the waiter had already woken up and moved
on to a completely unrelated code path, clobbering what was previously
data->task. Meanwhile, the waker was passing the clobbered garbage in
data->task to wake_up_process(), leading to the crash.

What's happening is that in between rq_qos_wake_function() deleting the
waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding
that it already got a token and returning. The race looks like this:

rq_qos_wait()                           rq_qos_wake_function()
==============================================================
prepare_to_wait_exclusive()
                                        data->got_token = true;
                                        list_del_init(&curr->entry);
if (data.got_token)
        break;
finish_wait(&rqw->wait, &data.wq);
  ^- returns immediately because
     list_empty_careful(&wq_entry->entry)
     is true
... return, go do something else ...
                                        wake_up_process(data->task)
                                          (NO LONGER VALID!)-^

Normally, finish_wait() is supposed to synchronize against the waker.
But, as noted above, it is returning immediately because the waitqueue
entry has already been removed from the waitqueue.

The bug is that rq_qos_wake_function() is accessing the waitqueue entry
AFTER deleting it. Note that autoremove_wake_function() wakes the waiter
and THEN deletes the waitqueue entry, which is the proper order.

Fix it by swapping the order. We also need to use
list_del_init_careful() to match the list_empty_careful() in
finish_wait().

Fixes: 38cfb5a ("blk-wbt: improve waking of tasks")
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
popcornmix pushed a commit that referenced this issue Oct 23, 2024
commit e972b08 upstream.

We're seeing crashes from rq_qos_wake_function that look like this:

  BUG: unable to handle page fault for address: ffffafe180a40084
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0
  Oops: Oops: 0002 [#1] PREEMPT SMP PTI
  CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 #11
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40
  Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00
  RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084
  RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011
  R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002
  R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003
  FS:  0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   <IRQ>
   try_to_wake_up+0x5a/0x6a0
   rq_qos_wake_function+0x71/0x80
   __wake_up_common+0x75/0xa0
   __wake_up+0x36/0x60
   scale_up.part.0+0x50/0x110
   wb_timer_fn+0x227/0x450
   ...

So rq_qos_wake_function() calls wake_up_process(data->task), which calls
try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock).

p comes from data->task, and data comes from the waitqueue entry, which
is stored on the waiter's stack in rq_qos_wait(). Analyzing the core
dump with drgn, I found that the waiter had already woken up and moved
on to a completely unrelated code path, clobbering what was previously
data->task. Meanwhile, the waker was passing the clobbered garbage in
data->task to wake_up_process(), leading to the crash.

What's happening is that in between rq_qos_wake_function() deleting the
waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding
that it already got a token and returning. The race looks like this:

rq_qos_wait()                           rq_qos_wake_function()
==============================================================
prepare_to_wait_exclusive()
                                        data->got_token = true;
                                        list_del_init(&curr->entry);
if (data.got_token)
        break;
finish_wait(&rqw->wait, &data.wq);
  ^- returns immediately because
     list_empty_careful(&wq_entry->entry)
     is true
... return, go do something else ...
                                        wake_up_process(data->task)
                                          (NO LONGER VALID!)-^

Normally, finish_wait() is supposed to synchronize against the waker.
But, as noted above, it is returning immediately because the waitqueue
entry has already been removed from the waitqueue.

The bug is that rq_qos_wake_function() is accessing the waitqueue entry
AFTER deleting it. Note that autoremove_wake_function() wakes the waiter
and THEN deletes the waitqueue entry, which is the proper order.

Fix it by swapping the order. We also need to use
list_del_init_careful() to match the list_empty_careful() in
finish_wait().

Fixes: 38cfb5a ("blk-wbt: improve waking of tasks")
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Oct 23, 2024
commit e972b08 upstream.

We're seeing crashes from rq_qos_wake_function that look like this:

  BUG: unable to handle page fault for address: ffffafe180a40084
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0
  Oops: Oops: 0002 [#1] PREEMPT SMP PTI
  CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 #11
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40
  Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00
  RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084
  RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011
  R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002
  R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003
  FS:  0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   <IRQ>
   try_to_wake_up+0x5a/0x6a0
   rq_qos_wake_function+0x71/0x80
   __wake_up_common+0x75/0xa0
   __wake_up+0x36/0x60
   scale_up.part.0+0x50/0x110
   wb_timer_fn+0x227/0x450
   ...

So rq_qos_wake_function() calls wake_up_process(data->task), which calls
try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock).

p comes from data->task, and data comes from the waitqueue entry, which
is stored on the waiter's stack in rq_qos_wait(). Analyzing the core
dump with drgn, I found that the waiter had already woken up and moved
on to a completely unrelated code path, clobbering what was previously
data->task. Meanwhile, the waker was passing the clobbered garbage in
data->task to wake_up_process(), leading to the crash.

What's happening is that in between rq_qos_wake_function() deleting the
waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding
that it already got a token and returning. The race looks like this:

rq_qos_wait()                           rq_qos_wake_function()
==============================================================
prepare_to_wait_exclusive()
                                        data->got_token = true;
                                        list_del_init(&curr->entry);
if (data.got_token)
        break;
finish_wait(&rqw->wait, &data.wq);
  ^- returns immediately because
     list_empty_careful(&wq_entry->entry)
     is true
... return, go do something else ...
                                        wake_up_process(data->task)
                                          (NO LONGER VALID!)-^

Normally, finish_wait() is supposed to synchronize against the waker.
But, as noted above, it is returning immediately because the waitqueue
entry has already been removed from the waitqueue.

The bug is that rq_qos_wake_function() is accessing the waitqueue entry
AFTER deleting it. Note that autoremove_wake_function() wakes the waiter
and THEN deletes the waitqueue entry, which is the proper order.

Fix it by swapping the order. We also need to use
list_del_init_careful() to match the list_empty_careful() in
finish_wait().

Fixes: 38cfb5a ("blk-wbt: improve waking of tasks")
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Nov 5, 2024
Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT
creates this splat when an MPTCP socket is created:

  =============================
  WARNING: suspicious RCU usage
  6.12.0-rc2+ #11 Not tainted
  -----------------------------
  net/mptcp/sched.c:44 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
  no locks held by mptcp_connect/176.

  stack backtrace:
  CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
   <TASK>
   dump_stack_lvl (lib/dump_stack.c:123)
   lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
   mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7))
   mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1))
   ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28)
   inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386)
   ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1))
   __sock_create (net/socket.c:1576)
   __sys_socket (net/socket.c:1671)
   ? __pfx___sys_socket (net/socket.c:1712)
   ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1))
   __x64_sys_socket (net/socket.c:1728)
   do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1))
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

That's because when the socket is initialised, rcu_read_lock() is not
used despite the explicit comment written above the declaration of
mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the
warning.

Fixes: 1730b2b ("mptcp: add sched in mptcp_sock")
Cc: stable@vger.kernel.org
Closes: multipath-tcp/mptcp_net-next#523
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241021-net-mptcp-sched-lock-v1-1-637759cf061c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
popcornmix pushed a commit that referenced this issue Nov 8, 2024
[ Upstream commit 3deb12c ]

Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT
creates this splat when an MPTCP socket is created:

  =============================
  WARNING: suspicious RCU usage
  6.12.0-rc2+ #11 Not tainted
  -----------------------------
  net/mptcp/sched.c:44 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
  no locks held by mptcp_connect/176.

  stack backtrace:
  CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
   <TASK>
   dump_stack_lvl (lib/dump_stack.c:123)
   lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
   mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7))
   mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1))
   ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28)
   inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386)
   ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1))
   __sock_create (net/socket.c:1576)
   __sys_socket (net/socket.c:1671)
   ? __pfx___sys_socket (net/socket.c:1712)
   ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1))
   __x64_sys_socket (net/socket.c:1728)
   do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1))
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

That's because when the socket is initialised, rcu_read_lock() is not
used despite the explicit comment written above the declaration of
mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the
warning.

Fixes: 1730b2b ("mptcp: add sched in mptcp_sock")
Cc: stable@vger.kernel.org
Closes: multipath-tcp/mptcp_net-next#523
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241021-net-mptcp-sched-lock-v1-1-637759cf061c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Nov 8, 2024
[ Upstream commit 3deb12c ]

Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT
creates this splat when an MPTCP socket is created:

  =============================
  WARNING: suspicious RCU usage
  6.12.0-rc2+ #11 Not tainted
  -----------------------------
  net/mptcp/sched.c:44 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
  no locks held by mptcp_connect/176.

  stack backtrace:
  CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
   <TASK>
   dump_stack_lvl (lib/dump_stack.c:123)
   lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
   mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7))
   mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1))
   ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28)
   inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386)
   ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1))
   __sock_create (net/socket.c:1576)
   __sys_socket (net/socket.c:1671)
   ? __pfx___sys_socket (net/socket.c:1712)
   ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1))
   __x64_sys_socket (net/socket.c:1728)
   do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1))
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

That's because when the socket is initialised, rcu_read_lock() is not
used despite the explicit comment written above the declaration of
mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the
warning.

Fixes: 1730b2b ("mptcp: add sched in mptcp_sock")
Cc: stable@vger.kernel.org
Closes: multipath-tcp/mptcp_net-next#523
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241021-net-mptcp-sched-lock-v1-1-637759cf061c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix pushed a commit that referenced this issue Nov 18, 2024
Disable strict aliasing, as has been done in the kernel proper for decades
(literally since before git history) to fix issues where gcc will optimize
away loads in code that looks 100% correct, but is _technically_ undefined
behavior, and thus can be thrown away by the compiler.

E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long)
pointer to a u64 (unsigned long long) pointer when setting PMCR.N via
u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores
the result and uses the original PMCR.

The issue is most easily observed by making set_pmcr_n() noinline and
wrapping the call with printf(), e.g. sans comments, for this code:

  printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);
  set_pmcr_n(&pmcr, pmcr_n);
  printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);

gcc-13 generates:

 0000000000401c90 <set_pmcr_n>:
  401c90:       f9400002        ldr     x2, [x0]
  401c94:       b3751022        bfi     x2, x1, #11, #5
  401c98:       f9000002        str     x2, [x0]
  401c9c:       d65f03c0        ret

 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>:
  402724:       aa1403e3        mov     x3, x20
  402728:       aa1503e2        mov     x2, x21
  40272c:       aa1603e0        mov     x0, x22
  402730:       aa1503e1        mov     x1, x21
  402734:       940060ff        bl      41ab30 <_IO_printf>
  402738:       aa1403e1        mov     x1, x20
  40273c:       910183e0        add     x0, sp, #0x60
  402740:       97fffd54        bl      401c90 <set_pmcr_n>
  402744:       aa1403e3        mov     x3, x20
  402748:       aa1503e2        mov     x2, x21
  40274c:       aa1503e1        mov     x1, x21
  402750:       aa1603e0        mov     x0, x22
  402754:       940060f7        bl      41ab30 <_IO_printf>

with the value stored in [sp + 0x60] ignored by both printf() above and
in the test proper, resulting in a false failure due to vcpu_set_reg()
simply storing the original value, not the intended value.

  $ ./vpmu_counter_access
  Random seed: 0x6b8b4567
  orig = 3040, next = 3040, want = 0
  orig = 3040, next = 3040, want = 0
  ==== Test Assertion Failure ====
    aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr)
    pid=71578 tid=71578 errno=9 - Bad file descriptor
       1        0x400673: run_access_test at vpmu_counter_access.c:522
       2         (inlined by) main at vpmu_counter_access.c:643
       3        0x4132d7: __libc_start_call_main at libc-start.o:0
       4        0x413653: __libc_start_main at ??:0
       5        0x40106f: _start at ??:0
    Failed to update PMCR.N to 0 (received: 6)

Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if
set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n()
is inlined in its sole caller.

Cc: stable@vger.kernel.org
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912
Signed-off-by: Sean Christopherson <seanjc@google.com>
popcornmix pushed a commit that referenced this issue Nov 25, 2024
commit 5b188cc upstream.

Disable strict aliasing, as has been done in the kernel proper for decades
(literally since before git history) to fix issues where gcc will optimize
away loads in code that looks 100% correct, but is _technically_ undefined
behavior, and thus can be thrown away by the compiler.

E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long)
pointer to a u64 (unsigned long long) pointer when setting PMCR.N via
u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores
the result and uses the original PMCR.

The issue is most easily observed by making set_pmcr_n() noinline and
wrapping the call with printf(), e.g. sans comments, for this code:

  printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);
  set_pmcr_n(&pmcr, pmcr_n);
  printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n);

gcc-13 generates:

 0000000000401c90 <set_pmcr_n>:
  401c90:       f9400002        ldr     x2, [x0]
  401c94:       b3751022        bfi     x2, x1, #11, #5
  401c98:       f9000002        str     x2, [x0]
  401c9c:       d65f03c0        ret

 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>:
  402724:       aa1403e3        mov     x3, x20
  402728:       aa1503e2        mov     x2, x21
  40272c:       aa1603e0        mov     x0, x22
  402730:       aa1503e1        mov     x1, x21
  402734:       940060ff        bl      41ab30 <_IO_printf>
  402738:       aa1403e1        mov     x1, x20
  40273c:       910183e0        add     x0, sp, #0x60
  402740:       97fffd54        bl      401c90 <set_pmcr_n>
  402744:       aa1403e3        mov     x3, x20
  402748:       aa1503e2        mov     x2, x21
  40274c:       aa1503e1        mov     x1, x21
  402750:       aa1603e0        mov     x0, x22
  402754:       940060f7        bl      41ab30 <_IO_printf>

with the value stored in [sp + 0x60] ignored by both printf() above and
in the test proper, resulting in a false failure due to vcpu_set_reg()
simply storing the original value, not the intended value.

  $ ./vpmu_counter_access
  Random seed: 0x6b8b4567
  orig = 3040, next = 3040, want = 0
  orig = 3040, next = 3040, want = 0
  ==== Test Assertion Failure ====
    aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr)
    pid=71578 tid=71578 errno=9 - Bad file descriptor
       1        0x400673: run_access_test at vpmu_counter_access.c:522
       2         (inlined by) main at vpmu_counter_access.c:643
       3        0x4132d7: __libc_start_call_main at libc-start.o:0
       4        0x413653: __libc_start_main at ??:0
       5        0x40106f: _start at ??:0
    Failed to update PMCR.N to 0 (received: 6)

Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if
set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n()
is inlined in its sole caller.

Cc: stable@vger.kernel.org
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix pushed a commit that referenced this issue Dec 7, 2024
[ Upstream commit 5bf1557 ]

test_progs uses glibc specific functions backtrace() and
backtrace_symbols_fd() to print backtrace in case of SIGSEGV.

Recent commit (see fixes) updated test_progs.c to define stub versions
of the same functions with attriubte "weak" in order to allow linking
test_progs against musl libc. Unfortunately this broke the backtrace
handling for glibc builds.

As it turns out, glibc defines backtrace() and backtrace_symbols_fd()
as weak:

  $ llvm-readelf --symbols /lib64/libc.so.6 \
     | grep -P '( backtrace_symbols_fd| backtrace)$'
  4910: 0000000000126b40   161 FUNC    WEAK   DEFAULT    16 backtrace
  6843: 0000000000126f90   852 FUNC    WEAK   DEFAULT    16 backtrace_symbols_fd

So does test_progs:

 $ llvm-readelf --symbols test_progs \
    | grep -P '( backtrace_symbols_fd| backtrace)$'
  2891: 00000000006ad190    15 FUNC    WEAK   DEFAULT    13 backtrace
 11215: 00000000006ad1a0    41 FUNC    WEAK   DEFAULT    13 backtrace_symbols_fd

In such situation dynamic linker is not obliged to favour glibc
implementation over the one defined in test_progs.

Compiling with the following simple modification to test_progs.c
demonstrates the issue:

  $ git diff
  ...
  \--- a/tools/testing/selftests/bpf/test_progs.c
  \+++ b/tools/testing/selftests/bpf/test_progs.c
  \@@ -1817,6 +1817,7 @@ int main(int argc, char **argv)
          if (err)
                  return err;

  +       *(int *)0xdeadbeef  = 42;
          err = cd_flavor_subdir(argv[0]);
          if (err)
                  return err;

  $ ./test_progs
  [0]: Caught signal #11!
  Stack trace:
  <backtrace not supported>
  Segmentation fault (core dumped)

Resolve this by hiding stub definitions behind __GLIBC__ macro check
instead of using "weak" attribute.

Fixes: c9a83e7 ("selftests/bpf: Fix compile if backtrace support missing in libc")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Tony Ambardar <tony.ambardar@gmail.com>
Reviewed-by: Tony Ambardar <tony.ambardar@gmail.com>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20241003210307.3847907-1-eddyz87@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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