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Wifi not detected #6

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ecc1 opened this issue Dec 3, 2016 · 2 comments
Closed

Wifi not detected #6

ecc1 opened this issue Dec 3, 2016 · 2 comments
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@ecc1
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ecc1 commented Dec 3, 2016

My understanding is that wifi should be working on the Edison, but I'm unable to see the device (I'm using an Intel mini-breakout board). I've tried with the i368_defconfig and others but I must be missing something.

Can someone post a known-working .config file that boots on a mini-breakout and has working wifi?

@andy-shev
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Please, don't duplicate, though feel free to reopen.
#4

I will ask for mini breakout (Currently I'm using only Arduino variant).

@andy-shev
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I commented in #4, but basically the recommendation just to start from the config I'm providing. If it works continue with yours stuff. But I can't reproduce the issue with it. So, it is a working one.

@andy-shev andy-shev self-assigned this Dec 20, 2016
htot pushed a commit to edison-fw/linux that referenced this issue Jun 26, 2017
The register_vlan_device would invoke free_netdev directly, when
register_vlan_dev failed. It would trigger the BUG_ON in free_netdev
if the dev was already registered. In this case, the netdev would be
freed in netdev_run_todo later.

So add one condition check now. Only when dev is not registered, then
free it directly.

The following is the part coredump when netdev_upper_dev_link failed
in register_vlan_dev. I removed the lines which are too long.

[  411.237457] ------------[ cut here ]------------
[  411.237458] kernel BUG at net/core/dev.c:7998!
[  411.237484] invalid opcode: 0000 [andy-shev#1] SMP
[  411.237705]  [last unloaded: 8021q]
[  411.237718] CPU: 1 PID: 12845 Comm: vconfig Tainted: G            E   4.12.0-rc5+ andy-shev#6
[  411.237737] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
[  411.237764] task: ffff9cbeb6685580 task.stack: ffffa7d2807d8000
[  411.237782] RIP: 0010:free_netdev+0x116/0x120
[  411.237794] RSP: 0018:ffffa7d2807dbdb0 EFLAGS: 00010297
[  411.237808] RAX: 0000000000000002 RBX: ffff9cbeb6ba8fd8 RCX: 0000000000001878
[  411.237826] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 0000000000000000
[  411.237844] RBP: ffffa7d2807dbdc8 R08: 0002986100029841 R09: 0002982100029801
[  411.237861] R10: 0004000100029980 R11: 0004000100029980 R12: ffff9cbeb6ba9000
[  411.238761] R13: ffff9cbeb6ba9060 R14: ffff9cbe60f1a000 R15: ffff9cbeb6ba9000
[  411.239518] FS:  00007fb690d81700(0000) GS:ffff9cbebb640000(0000) knlGS:0000000000000000
[  411.239949] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  411.240454] CR2: 00007f7115624000 CR3: 0000000077cdf000 CR4: 00000000003406e0
[  411.240936] Call Trace:
[  411.241462]  vlan_ioctl_handler+0x3f1/0x400 [8021q]
[  411.241910]  sock_ioctl+0x18b/0x2c0
[  411.242394]  do_vfs_ioctl+0xa1/0x5d0
[  411.242853]  ? sock_alloc_file+0xa6/0x130
[  411.243465]  SyS_ioctl+0x79/0x90
[  411.243900]  entry_SYSCALL_64_fastpath+0x1e/0xa9
[  411.244425] RIP: 0033:0x7fb69089a357
[  411.244863] RSP: 002b:00007ffcd04e0fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  411.245445] RAX: ffffffffffffffda RBX: 00007ffcd04e2884 RCX: 00007fb69089a357
[  411.245903] RDX: 00007ffcd04e0fd0 RSI: 0000000000008983 RDI: 0000000000000003
[  411.246527] RBP: 00007ffcd04e0fd0 R08: 0000000000000000 R09: 1999999999999999
[  411.246976] R10: 000000000000053f R11: 0000000000000202 R12: 0000000000000004
[  411.247414] R13: 00007ffcd04e1128 R14: 00007ffcd04e2888 R15: 0000000000000001
[  411.249129] RIP: free_netdev+0x116/0x120 RSP: ffffa7d2807dbdb0

Signed-off-by: Gao Feng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
htot pushed a commit to htot/linux that referenced this issue May 17, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various small fixes for mlxsw.

Patch andy-shev#1 fixes a warning generated by switchdev core when the driver
fails to insert an MDB entry in the commit phase.

Patches andy-shev#2-andy-shev#4 fix a warning in check_flush_dependency() that can be
triggered when a work item in a WQ_MEM_RECLAIM workqueue tries to flush
a non-WQ_MEM_RECLAIM workqueue.

It seems that the semantics of the WQ_MEM_RECLAIM flag are not very
clear [1] and that various patches have been sent to remove it from
various workqueues throughout the kernel [2][3][4] in order to silence
the warning.

These patches do the same for the workqueues created by mlxsw that
probably should not have been created with this flag in the first place.

Patch andy-shev#5 fixes a regression where an IP address cannot be assigned to a
VRF upper due to erroneous MAC validation check. Patch andy-shev#6 adds a test
case.

Patch andy-shev#7 adjusts Spectrum-2 shared buffer configuration to be compatible
with Spectrum-1. The problem and fix are described in detail in the
commit message.

Please consider patches andy-shev#1-andy-shev#5 for 5.0.y. I verified they apply cleanly.

[1] https://patchwork.kernel.org/patch/10791315/
[2] Commit ce162bf ("mac80211_hwsim: don't use WQ_MEM_RECLAIM")
[3] Commit 39baf10 ("IB/core: Fix use workqueue without WQ_MEM_RECLAIM")
[4] Commit 75215e5 ("iwcm: Don't allocate iwcm workqueue with WQ_MEM_RECLAIM")
====================

Signed-off-by: David S. Miller <[email protected]>
htot pushed a commit to htot/linux that referenced this issue May 17, 2019
By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  andy-shev#1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  andy-shev#2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  andy-shev#3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  andy-shev#4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  andy-shev#5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  andy-shev#6  map__put (map=0x1224df0) at util/map.c:299
  andy-shev#7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  andy-shev#8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  andy-shev#9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  andy-shev#10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  andy-shev#11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  andy-shev#12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  andy-shev#13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  andy-shev#14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  andy-shev#15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Eric Saint-Etienne <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Nov 2, 2020
Very sporadically I had test case btrfs/069 from fstests hanging (for
years, it is not a recent regression), with the following traces in
dmesg/syslog:

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

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

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

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

Which corresponds to:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      return ret

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

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

  $ drgn dump_block_groups.py

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

CC: [email protected] # 4.4+
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Nov 24, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

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

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

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

The full msan failure with track origins looks like:

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

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

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

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

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

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

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: [email protected]
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sandeep Dasgupta <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Nov 24, 2020
Actually, burst size is equal to '1 << desc->rqcfg.brst_size'.
we should use burst size, not desc->rqcfg.brst_size.

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

dmatest:

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

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

Before:

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

After this patch:

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

After this patch and increase dma clk to 400MHz:

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

Signed-off-by: Sugar Zhang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Mar 13, 2021
[ Upstream commit c5c97ca ]

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

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

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

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

Fixes: 045f8cd ("perf tests: Add a sample parsing test")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Mar 13, 2021
[ Upstream commit e8bd76e ]

kernel panic trace looks like:

 andy-shev#5 [ffffb9e08698fc80] do_page_fault at ffffffffb666e0d7
 andy-shev#6 [ffffb9e08698fcb0] page_fault at ffffffffb70010fe
    [exception RIP: amp_read_loc_assoc_final_data+63]
    RIP: ffffffffc06ab54f  RSP: ffffb9e08698fd68  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff8c8845a5a000  RCX: 0000000000000004
    RDX: 0000000000000000  RSI: ffff8c8b9153d000  RDI: ffff8c8845a5a000
    RBP: ffffb9e08698fe40   R8: 00000000000330e0   R9: ffffffffc0675c94
    R10: ffffb9e08698fe58  R11: 0000000000000001  R12: ffff8c8b9cbf6200
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff8c8b2026da0b
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 andy-shev#7 [ffffb9e08698fda8] hci_event_packet at ffffffffc0676904 [bluetooth]
 andy-shev#8 [ffffb9e08698fe50] hci_rx_work at ffffffffc06629ac [bluetooth]
 andy-shev#9 [ffffb9e08698fe98] process_one_work at ffffffffb66f95e7

hcon->amp_mgr seems NULL triggered kernel panic in following line inside
function amp_read_loc_assoc_final_data

        set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

Fixed by checking NULL for mgr.

Signed-off-by: Gopal Tiwari <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
andy-shev pushed a commit that referenced this issue Apr 12, 2021
The following deadlock is detected:

  truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write).

  PID: 14827  TASK: ffff881686a9af80  CPU: 20  COMMAND: "ora_p005_hrltd9"
   #0  __schedule at ffffffff818667cc
   #1  schedule at ffffffff81866de6
   #2  inode_dio_wait at ffffffff812a2d04
   #3  ocfs2_setattr at ffffffffc05f322e [ocfs2]
   #4  notify_change at ffffffff812a5a09
   #5  do_truncate at ffffffff812808f5
   #6  do_sys_ftruncate.constprop.18 at ffffffff81280cf2
   #7  sys_ftruncate at ffffffff81280d8e
   #8  do_syscall_64 at ffffffff81003949
   #9  entry_SYSCALL_64_after_hwframe at ffffffff81a001ad

dio completion path is going to complete one direct IO (decrement
inode->i_dio_count), but before that it hung at locking inode->i_rwsem:

   #0  __schedule+700 at ffffffff818667cc
   #1  schedule+54 at ffffffff81866de6
   #2  rwsem_down_write_failed+536 at ffffffff8186aa28
   #3  call_rwsem_down_write_failed+23 at ffffffff8185a1b7
   #4  down_write+45 at ffffffff81869c9d
   #5  ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2]
   #6  ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2]
   #7  dio_complete+140 at ffffffff812c873c
   #8  dio_aio_complete_work+25 at ffffffff812c89f9
   #9  process_one_work+361 at ffffffff810b1889
  #10  worker_thread+77 at ffffffff810b233d
  #11  kthread+261 at ffffffff810b7fd5
  #12  ret_from_fork+62 at ffffffff81a0035e

Thus above forms ABBA deadlock.  The same deadlock was mentioned in
upstream commit 28f5a8a ("ocfs2: should wait dio before inode lock
in ocfs2_setattr()").  It seems that that commit only removed the
cluster lock (the victim of above dead lock) from the ABBA deadlock
party.

End-user visible effects: Process hang in truncate -> ocfs2_setattr path
and other processes hang at ocfs2_dio_end_io_write path.

This is to fix the deadlock itself.  It removes inode_lock() call from
dio completion path to remove the deadlock and add ip_alloc_sem lock in
setattr path to synchronize the inode modifications.

[[email protected]: remove the "had_alloc_lock" as suggested]
  Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wengang Wang <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Jun 4, 2021
[ Upstream commit d65614a ]

I met below warning when cating a small size(about 80bytes) txt file
on 9pfs(msize=2097152 is passed to 9p mount option), the reason is we
miss iov_iter_advance() if the read count is 0 for zerocopy case, so
we didn't truncate the pipe, then iov_iter_pipe() thinks the pipe is
full. Fix it by removing the exception for 0 to ensure to call
iov_iter_advance() even on empty read for zerocopy case.

[    8.279568] WARNING: CPU: 0 PID: 39 at lib/iov_iter.c:1203 iov_iter_pipe+0x31/0x40
[    8.280028] Modules linked in:
[    8.280561] CPU: 0 PID: 39 Comm: cat Not tainted 5.11.0+ andy-shev#6
[    8.281260] RIP: 0010:iov_iter_pipe+0x31/0x40
[    8.281974] Code: 2b 42 54 39 42 5c 76 22 c7 07 20 00 00 00 48 89 57 18 8b 42 50 48 c7 47 08 b
[    8.283169] RSP: 0018:ffff888000cbbd80 EFLAGS: 00000246
[    8.283512] RAX: 0000000000000010 RBX: ffff888000117d00 RCX: 0000000000000000
[    8.283876] RDX: ffff88800031d600 RSI: 0000000000000000 RDI: ffff888000cbbd90
[    8.284244] RBP: ffff888000cbbe38 R08: 0000000000000000 R09: ffff8880008d2058
[    8.284605] R10: 0000000000000002 R11: ffff888000375510 R12: 0000000000000050
[    8.284964] R13: ffff888000cbbe80 R14: 0000000000000050 R15: ffff88800031d600
[    8.285439] FS:  00007f24fd8af600(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
[    8.285844] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.286150] CR2: 00007f24fd7d7b90 CR3: 0000000000c97000 CR4: 00000000000406b0
[    8.286710] Call Trace:
[    8.288279]  generic_file_splice_read+0x31/0x1a0
[    8.289273]  ? do_splice_to+0x2f/0x90
[    8.289511]  splice_direct_to_actor+0xcc/0x220
[    8.289788]  ? pipe_to_sendpage+0xa0/0xa0
[    8.290052]  do_splice_direct+0x8b/0xd0
[    8.290314]  do_sendfile+0x1ad/0x470
[    8.290576]  do_syscall_64+0x2d/0x40
[    8.290818]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[    8.291409] RIP: 0033:0x7f24fd7dca0a
[    8.292511] Code: c3 0f 1f 80 00 00 00 00 4c 89 d2 4c 89 c6 e9 bd fd ff ff 0f 1f 44 00 00 31 8
[    8.293360] RSP: 002b:00007ffc20932818 EFLAGS: 00000206 ORIG_RAX: 0000000000000028
[    8.293800] RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f24fd7dca0a
[    8.294153] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001
[    8.294504] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
[    8.294867] R10: 0000000001000000 R11: 0000000000000206 R12: 0000000000000003
[    8.295217] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
[    8.295782] ---[ end trace 63317af81b3ca24b ]---

Signed-off-by: Jisheng Zhang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Jun 4, 2021
[ Upstream commit 829933e ]

For each device, the nosy driver allocates a pcilynx structure.
A use-after-free might happen in the following scenario:

 1. Open nosy device for the first time and call ioctl with command
    NOSY_IOC_START, then a new client A will be malloced and added to
    doubly linked list.
 2. Open nosy device for the second time and call ioctl with command
    NOSY_IOC_START, then a new client B will be malloced and added to
    doubly linked list.
 3. Call ioctl with command NOSY_IOC_START for client A, then client A
    will be readded to the doubly linked list. Now the doubly linked
    list is messed up.
 4. Close the first nosy device and nosy_release will be called. In
    nosy_release, client A will be unlinked and freed.
 5. Close the second nosy device, and client A will be referenced,
    resulting in UAF.

The root cause of this bug is that the element in the doubly linked list
is reentered into the list.

Fix this bug by adding a check before inserting a client.  If a client
is already in the linked list, don't insert it.

The following KASAN report reveals it:

   BUG: KASAN: use-after-free in nosy_release+0x1ea/0x210
   Write of size 8 at addr ffff888102ad7360 by task poc
   CPU: 3 PID: 337 Comm: poc Not tainted 5.12.0-rc5+ andy-shev#6
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
   Call Trace:
     nosy_release+0x1ea/0x210
     __fput+0x1e2/0x840
     task_work_run+0xe8/0x180
     exit_to_user_mode_prepare+0x114/0x120
     syscall_exit_to_user_mode+0x1d/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   Allocated by task 337:
     nosy_open+0x154/0x4d0
     misc_open+0x2ec/0x410
     chrdev_open+0x20d/0x5a0
     do_dentry_open+0x40f/0xe80
     path_openat+0x1cf9/0x37b0
     do_filp_open+0x16d/0x390
     do_sys_openat2+0x11d/0x360
     __x64_sys_open+0xfd/0x1a0
     do_syscall_64+0x33/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   Freed by task 337:
     kfree+0x8f/0x210
     nosy_release+0x158/0x210
     __fput+0x1e2/0x840
     task_work_run+0xe8/0x180
     exit_to_user_mode_prepare+0x114/0x120
     syscall_exit_to_user_mode+0x1d/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   The buggy address belongs to the object at ffff888102ad7300 which belongs to the cache kmalloc-128 of size 128
   The buggy address is located 96 bytes inside of 128-byte region [ffff888102ad7300, ffff888102ad7380)

[ Modified to use 'list_empty()' inside proper lock  - Linus ]

Link: https://lore.kernel.org/lkml/[email protected]/
Reported-and-tested-by: 马哲宇 (Zheyu Ma) <[email protected]>
Signed-off-by: Zheyu Ma <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Stefan Richter <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Jun 4, 2021
commit 90bd070 upstream.

The following deadlock is detected:

  truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write).

  PID: 14827  TASK: ffff881686a9af80  CPU: 20  COMMAND: "ora_p005_hrltd9"
   #0  __schedule at ffffffff818667cc
   andy-shev#1  schedule at ffffffff81866de6
   andy-shev#2  inode_dio_wait at ffffffff812a2d04
   andy-shev#3  ocfs2_setattr at ffffffffc05f322e [ocfs2]
   andy-shev#4  notify_change at ffffffff812a5a09
   andy-shev#5  do_truncate at ffffffff812808f5
   andy-shev#6  do_sys_ftruncate.constprop.18 at ffffffff81280cf2
   andy-shev#7  sys_ftruncate at ffffffff81280d8e
   andy-shev#8  do_syscall_64 at ffffffff81003949
   andy-shev#9  entry_SYSCALL_64_after_hwframe at ffffffff81a001ad

dio completion path is going to complete one direct IO (decrement
inode->i_dio_count), but before that it hung at locking inode->i_rwsem:

   #0  __schedule+700 at ffffffff818667cc
   andy-shev#1  schedule+54 at ffffffff81866de6
   andy-shev#2  rwsem_down_write_failed+536 at ffffffff8186aa28
   andy-shev#3  call_rwsem_down_write_failed+23 at ffffffff8185a1b7
   andy-shev#4  down_write+45 at ffffffff81869c9d
   andy-shev#5  ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2]
   andy-shev#6  ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2]
   andy-shev#7  dio_complete+140 at ffffffff812c873c
   andy-shev#8  dio_aio_complete_work+25 at ffffffff812c89f9
   andy-shev#9  process_one_work+361 at ffffffff810b1889
  andy-shev#10  worker_thread+77 at ffffffff810b233d
  andy-shev#11  kthread+261 at ffffffff810b7fd5
  andy-shev#12  ret_from_fork+62 at ffffffff81a0035e

Thus above forms ABBA deadlock.  The same deadlock was mentioned in
upstream commit 28f5a8a ("ocfs2: should wait dio before inode lock
in ocfs2_setattr()").  It seems that that commit only removed the
cluster lock (the victim of above dead lock) from the ABBA deadlock
party.

End-user visible effects: Process hang in truncate -> ocfs2_setattr path
and other processes hang at ocfs2_dio_end_io_write path.

This is to fix the deadlock itself.  It removes inode_lock() call from
dio completion path to remove the deadlock and add ip_alloc_sem lock in
setattr path to synchronize the inode modifications.

[[email protected]: remove the "had_alloc_lock" as suggested]
  Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wengang Wang <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
htot pushed a commit to edison-fw/linux that referenced this issue Jun 4, 2021
[ Upstream commit bbd6f0a ]

In bnxt_rx_pkt(), the RX buffers are expected to complete in order.
If the RX consumer index indicates an out of order buffer completion,
it means we are hitting a hardware bug and the driver will abort all
remaining RX packets and reset the RX ring.  The RX consumer index
that we pass to bnxt_discard_rx() is not correct.  We should be
passing the current index (tmp_raw_cons) instead of the old index
(raw_cons).  This bug can cause us to be at the wrong index when
trying to abort the next RX packet.  It can crash like this:

 #0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007
 andy-shev#1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232
 andy-shev#2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e
 andy-shev#3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978
 andy-shev#4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0
 andy-shev#5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e
 andy-shev#6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24
 andy-shev#7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e
 andy-shev#8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12
 andy-shev#9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5
    [exception RIP: bnxt_rx_pkt+237]
    RIP: ffffffffc0259cdd  RSP: ffff9bbcdf5c3d98  RFLAGS: 00010213
    RAX: 000000005dd8097f  RBX: ffff9ba4cb11b7e0  RCX: ffffa923cf6e9000
    RDX: 0000000000000fff  RSI: 0000000000000627  RDI: 0000000000001000
    RBP: ffff9bbcdf5c3e60   R8: 0000000000420003   R9: 000000000000020d
    R10: ffffa923cf6ec138  R11: ffff9bbcdf5c3e83  R12: ffff9ba4d6f928c0
    R13: ffff9ba4cac28080  R14: ffff9ba4cb11b7f0  R15: ffff9ba4d5a30000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Fixes: a1b0e4e ("bnxt_en: Improve RX consumer index validity check.")
Reviewed-by: Pavan Chebbi <[email protected]>
Reviewed-by: Andy Gospodarek <[email protected]>
Signed-off-by: Michael Chan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
htot pushed a commit to htot/linux that referenced this issue Feb 3, 2022
In line:
	upper = info->upper_dev;
We access upper_dev field, which is related only for particular events
(e.g. event == NETDEV_CHANGEUPPER). So, this line cause invalid memory
access for another events,
when ptr is not netdev_notifier_changeupper_info.

The KASAN logs are as follows:

[   30.123165] BUG: KASAN: stack-out-of-bounds in prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera]
[   30.133336] Read of size 8 at addr ffff80000cf772b0 by task udevd/778
[   30.139866]
[   30.141398] CPU: 0 PID: 778 Comm: udevd Not tainted 5.16.0-rc3 andy-shev#6
[   30.147588] Hardware name: DNI AmazonGo1 A7040 board (DT)
[   30.153056] Call trace:
[   30.155547]  dump_backtrace+0x0/0x2c0
[   30.159320]  show_stack+0x18/0x30
[   30.162729]  dump_stack_lvl+0x68/0x84
[   30.166491]  print_address_description.constprop.0+0x74/0x2b8
[   30.172346]  kasan_report+0x1e8/0x250
[   30.176102]  __asan_load8+0x98/0xe0
[   30.179682]  prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera]
[   30.186847]  prestera_netdev_event_handler+0x1b4/0x1c0 [prestera]
[   30.193313]  raw_notifier_call_chain+0x74/0xa0
[   30.197860]  call_netdevice_notifiers_info+0x68/0xc0
[   30.202924]  register_netdevice+0x3cc/0x760
[   30.207190]  register_netdev+0x24/0x50
[   30.211015]  prestera_device_register+0x8a0/0xba0 [prestera]

Fixes: 3d5048c ("net: marvell: prestera: move netdev topology validation to prestera_main")
Signed-off-by: Yevhen Orlov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
htot pushed a commit to htot/linux that referenced this issue Feb 3, 2022
The fixed commit attempts to close inject.output even if it was never
opened e.g.

  $ perf record uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.002 MB perf.data (7 samples) ]
  $ perf inject -i perf.data --vm-time-correlation=dry-run
  Segmentation fault (core dumped)
  $ gdb --quiet perf
  Reading symbols from perf...
  (gdb) r inject -i perf.data --vm-time-correlation=dry-run
  Starting program: /home/ahunter/bin/perf inject -i perf.data --vm-time-correlation=dry-run
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

  Program received signal SIGSEGV, Segmentation fault.
  0x00007eff8afeef5b in _IO_new_fclose (fp=0x0) at iofclose.c:48
  48      iofclose.c: No such file or directory.
  (gdb) bt
  #0  0x00007eff8afeef5b in _IO_new_fclose (fp=0x0) at iofclose.c:48
  andy-shev#1  0x0000557fc7b74f92 in perf_data__close (data=data@entry=0x7ffcdafa6578) at util/data.c:376
  andy-shev#2  0x0000557fc7a6b807 in cmd_inject (argc=<optimized out>, argv=<optimized out>) at builtin-inject.c:1085
  andy-shev#3  0x0000557fc7ac4783 in run_builtin (p=0x557fc8074878 <commands+600>, argc=4, argv=0x7ffcdafb6a60) at perf.c:313
  andy-shev#4  0x0000557fc7a25d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  andy-shev#5  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  andy-shev#6  main (argc=4, argv=0x7ffcdafb6a60) at perf.c:539
  (gdb)

Fixes: 02e6246 ("perf inject: Close inject.output on exit")
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
htot pushed a commit to htot/linux that referenced this issue Feb 3, 2022
The fixed commit attempts to get the output file descriptor even if the
file was never opened e.g.

  $ perf record uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.002 MB perf.data (7 samples) ]
  $ perf inject -i perf.data --vm-time-correlation=dry-run
  Segmentation fault (core dumped)
  $ gdb --quiet perf
  Reading symbols from perf...
  (gdb) r inject -i perf.data --vm-time-correlation=dry-run
  Starting program: /home/ahunter/bin/perf inject -i perf.data --vm-time-correlation=dry-run
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

  Program received signal SIGSEGV, Segmentation fault.
  __GI___fileno (fp=0x0) at fileno.c:35
  35      fileno.c: No such file or directory.
  (gdb) bt
  #0  __GI___fileno (fp=0x0) at fileno.c:35
  andy-shev#1  0x00005621e48dd987 in perf_data__fd (data=0x7fff4c68bd08) at util/data.h:72
  andy-shev#2  perf_data__fd (data=0x7fff4c68bd08) at util/data.h:69
  andy-shev#3  cmd_inject (argc=<optimized out>, argv=0x7fff4c69c1f0) at builtin-inject.c:1017
  andy-shev#4  0x00005621e4936783 in run_builtin (p=0x5621e4ee6878 <commands+600>, argc=4, argv=0x7fff4c69c1f0) at perf.c:313
  andy-shev#5  0x00005621e4897d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  andy-shev#6  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  andy-shev#7  main (argc=4, argv=0x7fff4c69c1f0) at perf.c:539
  (gdb)

Fixes: 0ae0389 ("perf tools: Pass a fd to perf_file_header__read_pipe()")
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
andy-shev pushed a commit that referenced this issue Jan 14, 2024
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   #9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   #10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   #11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   #12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   #13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   #14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   #15 [ffff88aa841efb88] device_del at ffffffff82179d23
   #16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   #17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   #18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   #19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   #20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   #21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
andy-shev pushed a commit that referenced this issue Jan 14, 2024
When working on LED support for r8169 I got the following lockdep
warning. Easiest way to prevent this scenario seems to be to take
the RTNL lock before the trigger_data lock in set_device_name().

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-next-20231124+ #2 Not tainted
------------------------------------------------------
bash/383 is trying to acquire lock:
ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev]

but task is already holding lock:
ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       rtnl_lock+0x12/0x20
       set_device_name+0xa9/0x120 [ledtrig_netdev]
       netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

-> #0 (&trigger_data->lock){+.+.}-{3:3}:
       __lock_acquire+0x1459/0x25a0
       lock_acquire+0xc8/0x2d0
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
       call_netdevice_register_net_notifiers+0x5a/0x100
       register_netdevice_notifier+0x85/0x120
       netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock(&trigger_data->lock);
                               lock(rtnl_mutex);
  lock(&trigger_data->lock);

 *** DEADLOCK ***

8 locks held by bash/383:
 #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0
 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210
 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210
 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140
 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140
 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140
 #6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120
 #7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

stack backtrace:
CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2
Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
Call Trace:
 <TASK>
 dump_stack_lvl+0x5c/0xd0
 dump_stack+0x10/0x20
 print_circular_bug+0x2dd/0x410
 check_noncircular+0x131/0x150
 __lock_acquire+0x1459/0x25a0
 lock_acquire+0xc8/0x2d0
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 __mutex_lock+0x9b/0xb50
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __this_cpu_preempt_check+0x13/0x20
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __cancel_work_timer+0x11c/0x1b0
 ? __mutex_lock+0x123/0xb50
 mutex_lock_nested+0x16/0x20
 ? mutex_lock_nested+0x16/0x20
 netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 call_netdevice_register_net_notifiers+0x5a/0x100
 register_netdevice_notifier+0x85/0x120
 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
 led_trigger_set+0x172/0x2c0
 ? preempt_count_add+0x49/0xc0
 led_trigger_write+0xf1/0x140
 sysfs_kf_bin_write+0x5d/0x80
 kernfs_fop_write_iter+0x15d/0x210
 vfs_write+0x1f0/0x510
 ksys_write+0x6c/0xf0
 __x64_sys_write+0x14/0x20
 do_syscall_64+0x3f/0xf0
 entry_SYSCALL_64_after_hwframe+0x6c/0x74
RIP: 0033:0x7f269055d034
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034
RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001
RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000
 </TASK>

Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode")
Cc: [email protected]
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
andy-shev pushed a commit that referenced this issue Jan 14, 2024
I conducted real-time testing and observed that
madvise_cold_or_pageout_pte_range() causes significant latency under
memory pressure, which can be effectively reduced by adding cond_resched()
within the loop.

I tested on the LicheePi 4A board using Cylictest for latency testing and
Ftrace for latency tracing.  The board uses TH1520 processor and has a
memory size of 8GB.  The kernel version is 6.5.0 with the PREEMPT_RT patch
applied.

The script I tested is as follows:

echo wakeup_rt > /sys/kernel/tracing/current_tracer
echo 1 > /sys/kernel/tracing/tracing_on
echo 0 > /sys/kernel/tracing/tracing_max_latency
stress-ng --vm 8 --vm-bytes 2G &
cyclictest --mlockall --smp --priority=99 --distance=0 --duration=30m
echo 0 > /sys/kernel/tracing/tracing_on
cat /sys/kernel/tracing/trace 

The tracing results before modification are as follows:

# tracer: wakeup_rt
#
# wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00003-g999d221864bf
# --------------------------------------------------------------------
# latency: 2552 us, #6/6, CPU#3 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4)
#    -----------------
#    | task: cyclictest-196 (uid:0 nice:0 policy:1 rt_prio:99)
#    -----------------
#
#                    _--------=> CPU#
#                   / _-------=> irqs-off/BH-disabled
#                  | / _------=> need-resched
#                  || / _-----=> need-resched-lazy
#                  ||| / _----=> hardirq/softirq
#                  |||| / _---=> preempt-depth
#                  ||||| / _--=> preempt-lazy-depth
#                  |||||| / _-=> migrate-disable
#                  ||||||| /     delay
#  cmd     pid     |||||||| time  |   caller
#     \   /        ||||||||  \    |    /
stress-n-206       3dn.h512    2us :      206:120:R   + [003]     196:  0:R cyclictest
stress-n-206       3dn.h512    7us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup
 => ttwu_do_activate
 => try_to_wake_up
 => wake_up_process
 => hrtimer_wakeup
 => __hrtimer_run_queues
 => hrtimer_interrupt
 => riscv_timer_interrupt
 => handle_percpu_devid_irq
 => generic_handle_domain_irq
 => riscv_intc_irq
 => handle_riscv_irq
 => do_irq
stress-n-206       3dn.h512    9us#: 0
stress-n-206       3d...3.. 2544us : __schedule
stress-n-206       3d...3.. 2545us :      206:120:R ==> [003]     196:  0:R cyclictest
stress-n-206       3d...3.. 2551us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup_sched_switch
 => __schedule
 => preempt_schedule
 => migrate_enable
 => rt_spin_unlock
 => madvise_cold_or_pageout_pte_range
 => walk_pgd_range
 => __walk_page_range
 => walk_page_range
 => madvise_pageout
 => madvise_vma_behavior
 => do_madvise
 => sys_madvise
 => do_trap_ecall_u
 => ret_from_exception

The tracing results after modification are as follows:

# tracer: wakeup_rt
#
# wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00004-gca3876fc69a6-dirty
# --------------------------------------------------------------------
# latency: 1689 us, #6/6, CPU#0 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4)
#    -----------------
#    | task: cyclictest-217 (uid:0 nice:0 policy:1 rt_prio:99)
#    -----------------
#
#                    _--------=> CPU#
#                   / _-------=> irqs-off/BH-disabled
#                  | / _------=> need-resched
#                  || / _-----=> need-resched-lazy
#                  ||| / _----=> hardirq/softirq
#                  |||| / _---=> preempt-depth
#                  ||||| / _--=> preempt-lazy-depth
#                  |||||| / _-=> migrate-disable
#                  ||||||| /     delay
#  cmd     pid     |||||||| time  |   caller
#     \   /        ||||||||  \    |    /
stress-n-232       0dn.h413    1us+:      232:120:R   + [000]     217:  0:R cyclictest
stress-n-232       0dn.h413   12us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup
 => ttwu_do_activate
 => try_to_wake_up
 => wake_up_process
 => hrtimer_wakeup
 => __hrtimer_run_queues
 => hrtimer_interrupt
 => riscv_timer_interrupt
 => handle_percpu_devid_irq
 => generic_handle_domain_irq
 => riscv_intc_irq
 => handle_riscv_irq
 => do_irq
stress-n-232       0dn.h413   19us#: 0
stress-n-232       0d...3.. 1671us : __schedule
stress-n-232       0d...3.. 1676us+:      232:120:R ==> [000]     217:  0:R cyclictest
stress-n-232       0d...3.. 1687us : <stack trace>
 => __ftrace_trace_stack
 => __trace_stack
 => probe_wakeup_sched_switch
 => __schedule
 => preempt_schedule
 => migrate_enable
 => free_unref_page_list
 => release_pages
 => free_pages_and_swap_cache
 => tlb_batch_pages_flush
 => tlb_flush_mmu
 => unmap_page_range
 => unmap_vmas
 => unmap_region
 => do_vmi_align_munmap.constprop.0
 => do_vmi_munmap
 => __vm_munmap
 => sys_munmap
 => do_trap_ecall_u
 => ret_from_exception

After the modification, the cause of maximum latency is no longer
madvise_cold_or_pageout_pte_range(), so this modification can reduce the
latency caused by madvise_cold_or_pageout_pte_range().


Currently the madvise_cold_or_pageout_pte_range() function exhibits
significant latency under memory pressure, which can be effectively
reduced by adding cond_resched() within the loop.

When the batch_count reaches SWAP_CLUSTER_MAX, we reschedule
the task to ensure fairness and avoid long lock holding times.

Link: https://lkml.kernel.org/r/85363861af65fac66c7a98c251906afc0d9c8098.1695291046.git.wangjiexun@tinylab.org
Signed-off-by: Jiexun Wang <[email protected]>
Cc: Zhangjin Wu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
andy-shev pushed a commit that referenced this issue Jan 14, 2024
…te_call_indirect

kprobe_emulate_call_indirect currently uses int3_emulate_call to emulate
indirect calls. However, int3_emulate_call always assumes the size of
the call to be 5 bytes when calculating the return address. This is
incorrect for register-based indirect calls in x86, which can be either
2 or 3 bytes depending on whether REX prefix is used. At kprobe runtime,
the incorrect return address causes control flow to land onto the wrong
place after return -- possibly not a valid instruction boundary. This
can lead to a panic like the following:

[    7.308204][    C1] BUG: unable to handle page fault for address: 000000000002b4d8
[    7.308883][    C1] #PF: supervisor read access in kernel mode
[    7.309168][    C1] #PF: error_code(0x0000) - not-present page
[    7.309461][    C1] PGD 0 P4D 0
[    7.309652][    C1] Oops: 0000 [#1] SMP
[    7.309929][    C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.7.0-rc5-trace-for-next #6
[    7.310397][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
[    7.311068][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.311349][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.312512][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.312899][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.313334][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.313702][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.314146][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.314509][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.314951][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.315396][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.315691][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.316153][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.316508][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.316948][    C1] Call Trace:
[    7.317123][    C1]  <IRQ>
[    7.317279][    C1]  ? __die_body+0x64/0xb0
[    7.317482][    C1]  ? page_fault_oops+0x248/0x370
[    7.317712][    C1]  ? __wake_up+0x96/0xb0
[    7.317964][    C1]  ? exc_page_fault+0x62/0x130
[    7.318211][    C1]  ? asm_exc_page_fault+0x22/0x30
[    7.318444][    C1]  ? __cfi_native_send_call_func_single_ipi+0x10/0x10
[    7.318860][    C1]  ? default_idle+0xb/0x10
[    7.319063][    C1]  ? __common_interrupt+0x52/0xc0
[    7.319330][    C1]  common_interrupt+0x78/0x90
[    7.319546][    C1]  </IRQ>
[    7.319679][    C1]  <TASK>
[    7.319854][    C1]  asm_common_interrupt+0x22/0x40
[    7.320082][    C1] RIP: 0010:default_idle+0xb/0x10
[    7.320309][    C1] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 66 90 0f 00 2d 09 b9 3b 00 fb f4 <fa> c3 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 e9
[    7.321449][    C1] RSP: 0018:ffffc9000009bee8 EFLAGS: 00000256
[    7.321808][    C1] RAX: ffff88813bca8b68 RBX: 0000000000000001 RCX: 000000000001ef0c
[    7.322227][    C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000001ef0c
[    7.322656][    C1] RBP: ffffc9000009bef8 R08: 8000000000000000 R09: 00000000000008c2
[    7.323083][    C1] R10: 0000000000000000 R11: ffffffff81058e70 R12: 0000000000000000
[    7.323530][    C1] R13: ffff8881002b30c0 R14: 0000000000000000 R15: 0000000000000000
[    7.323948][    C1]  ? __cfi_lapic_next_deadline+0x10/0x10
[    7.324239][    C1]  default_idle_call+0x31/0x50
[    7.324464][    C1]  do_idle+0xd3/0x240
[    7.324690][    C1]  cpu_startup_entry+0x25/0x30
[    7.324983][    C1]  start_secondary+0xb4/0xc0
[    7.325217][    C1]  secondary_startup_64_no_verify+0x179/0x17b
[    7.325498][    C1]  </TASK>
[    7.325641][    C1] Modules linked in:
[    7.325906][    C1] CR2: 000000000002b4d8
[    7.326104][    C1] ---[ end trace 0000000000000000 ]---
[    7.326354][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.326614][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.327570][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.327910][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.328273][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.328632][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.329223][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.329780][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.330193][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.330632][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.331050][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.331454][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.331854][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.332236][    C1] Kernel panic - not syncing: Fatal exception in interrupt
[    7.332730][    C1] Kernel Offset: disabled
[    7.333044][    C1] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

The relevant assembly code is (from objdump, faulting address
highlighted):

ffffffff8102ed9d:       41 ff d3                  call   *%r11
ffffffff8102eda0:       65 48 <8b> 05 30 c7 ff    mov    %gs:0x7effc730(%rip),%rax

The emulation incorrectly sets the return address to be ffffffff8102ed9d
+ 0x5 = ffffffff8102eda2, which is the 8b byte in the middle of the next
mov. This in turn causes incorrect subsequent instruction decoding and
eventually triggers the page fault above.

Instead of invoking int3_emulate_call, perform push and jmp emulation
directly in kprobe_emulate_call_indirect. At this point we can obtain
the instruction size from p->ainsn.size so that we can calculate the
correct return address.

Link: https://lore.kernel.org/all/[email protected]/

Fixes: 6256e66 ("x86/kprobes: Use int3 instead of debug trap for single-step")
Cc: [email protected]
Signed-off-by: Jinghao Jia <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
andy-shev pushed a commit that referenced this issue Apr 16, 2024
At current x1e80100 interface table, interface #3 is wrongly
connected to DP controller #0 and interface #4 wrongly connected
to DP controller #2. Fix this problem by connect Interface #3 to
DP controller #0 and interface #4 connect to DP controller #1.
Also add interface #6, #7 and #8 connections to DP controller to
complete x1e80100 interface table.

Changs in V3:
-- add v2 changes log

Changs in V2:
-- add x1e80100 to subject
-- add Fixes

Fixes: e3b1f36 ("drm/msm/dpu: Add X1E80100 support")
Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Reviewed-by: Abel Vesa <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/585549/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Abhinav Kumar <[email protected]>
andy-shev pushed a commit that referenced this issue Apr 25, 2024
…git/netfilter/nf

netfilter pull request 24-04-11

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patches #1 and #2 add missing rcu read side lock when iterating over
expression and object type list which could race with module removal.

Patch #3 prevents promisc packet from visiting the bridge/input hook
	 to amend a recent fix to address conntrack confirmation race
	 in br_netfilter and nf_conntrack_bridge.

Patch #4 adds and uses iterate decorator type to fetch the current
	 pipapo set backend datastructure view when netlink dumps the
	 set elements.

Patch #5 fixes removal of duplicate elements in the pipapo set backend.

Patch #6 flowtable validates pppoe header before accessing it.

Patch #7 fixes flowtable datapath for pppoe packets, otherwise lookup
         fails and pppoe packets follow classic path.
====================

Signed-off-by: David S. Miller <[email protected]>
andy-shev pushed a commit that referenced this issue Apr 25, 2024
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.

net_ratelimit mechanism can be used to limit the dumping rate.

PID: 33036    TASK: ffff949da6f20000  CPU: 23   COMMAND: "vhost-32980"
 #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
 #3 [fffffe00003fced0] do_nmi at ffffffff8922660d
 #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
    [exception RIP: io_serial_in+20]
    RIP: ffffffff89792594  RSP: ffffa655314979e8  RFLAGS: 00000002
    RAX: ffffffff89792500  RBX: ffffffff8af428a0  RCX: 0000000000000000
    RDX: 00000000000003fd  RSI: 0000000000000005  RDI: ffffffff8af428a0
    RBP: 0000000000002710   R8: 0000000000000004   R9: 000000000000000f
    R10: 0000000000000000  R11: ffffffff8acbf64f  R12: 0000000000000020
    R13: ffffffff8acbf698  R14: 0000000000000058  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594
 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
 #8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
 #9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124
 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
 #12 [ffffa65531497b68] printk at ffffffff89318306
 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
 #14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
 #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
 #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
 #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
 #18 [ffffa65531497f10] kthread at ffffffff892d2e72
 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f

Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors")
Signed-off-by: Lei Chen <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Acked-by: Jason Wang <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
andy-shev pushed a commit that referenced this issue Aug 26, 2024
We might run into a SIE validity if gisa has been disabled either via using
kernel parameter "kvm.use_gisa=0" or by setting the related sysfs
attribute to N (echo N >/sys/module/kvm/parameters/use_gisa).

The validity is caused by an invalid value in the SIE control block's
gisa designation. That happens because we pass the uninitialized gisa
origin to virt_to_phys() before writing it to the gisa designation.

To fix this we return 0 in kvm_s390_get_gisa_desc() if the origin is 0.
kvm_s390_get_gisa_desc() is used to determine which gisa designation to
set in the SIE control block. A value of 0 in the gisa designation disables
gisa usage.

The issue surfaces in the host kernel with the following kernel message as
soon a new kvm guest start is attemted.

kvm: unhandled validity intercept 0x1011
WARNING: CPU: 0 PID: 781237 at arch/s390/kvm/intercept.c:101 kvm_handle_sie_intercept+0x42e/0x4d0 [kvm]
Modules linked in: vhost_net tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT xt_tcpudp nft_compat x_tables nf_nat_tftp nf_conntrack_tftp vfio_pci_core irqbypass vhost_vsock vmw_vsock_virtio_transport_common vsock vhost vhost_iotlb kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables sunrpc mlx5_ib ib_uverbs ib_core mlx5_core uvdevice s390_trng eadm_sch vfio_ccw zcrypt_cex4 mdev vfio_iommu_type1 vfio sch_fq_codel drm i2c_core loop drm_panel_orientation_quirks configfs nfnetlink lcs ctcm fsm dm_service_time ghash_s390 prng chacha_s390 libchacha aes_s390 des_s390 libdes sha3_512_s390 sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common dm_mirror dm_region_hash dm_log zfcp scsi_transport_fc scsi_dh_rdac scsi_dh_emc scsi_dh_alua pkey zcrypt dm_multipath rng_core autofs4 [last unloaded: vfio_pci]
CPU: 0 PID: 781237 Comm: CPU 0/KVM Not tainted 6.10.0-08682-gcad9f11498ea #6
Hardware name: IBM 3931 A01 701 (LPAR)
Krnl PSW : 0704c00180000000 000003d93deb0122 (kvm_handle_sie_intercept+0x432/0x4d0 [kvm])
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 000003d900000027 000003d900000023 0000000000000028 000002cd00000000
           000002d063a00900 00000359c6daf708 00000000000bebb5 0000000000001eff
           000002cfd82e9000 000002cfd80bc000 0000000000001011 000003d93deda412
           000003ff8962df98 000003d93de77ce0 000003d93deb011e 00000359c6daf960
Krnl Code: 000003d93deb0112: c020fffe7259	larl	%r2,000003d93de7e5c4
           000003d93deb0118: c0e53fa8beac	brasl	%r14,000003d9bd3c7e70
          #000003d93deb011e: af000000		mc	0,0
          >000003d93deb0122: a728ffea		lhi	%r2,-22
           000003d93deb0126: a7f4fe24		brc	15,000003d93deafd6e
           000003d93deb012a: 9101f0b0		tm	176(%r15),1
           000003d93deb012e: a774fe48		brc	7,000003d93deafdbe
           000003d93deb0132: 40a0f0ae		sth	%r10,174(%r15)
Call Trace:
 [<000003d93deb0122>] kvm_handle_sie_intercept+0x432/0x4d0 [kvm]
([<000003d93deb011e>] kvm_handle_sie_intercept+0x42e/0x4d0 [kvm])
 [<000003d93deacc10>] vcpu_post_run+0x1d0/0x3b0 [kvm]
 [<000003d93deaceda>] __vcpu_run+0xea/0x2d0 [kvm]
 [<000003d93dead9da>] kvm_arch_vcpu_ioctl_run+0x16a/0x430 [kvm]
 [<000003d93de93ee0>] kvm_vcpu_ioctl+0x190/0x7c0 [kvm]
 [<000003d9bd728b4e>] vfs_ioctl+0x2e/0x70
 [<000003d9bd72a092>] __s390x_sys_ioctl+0xc2/0xd0
 [<000003d9be0e9222>] __do_syscall+0x1f2/0x2e0
 [<000003d9be0f9a90>] system_call+0x70/0x98
Last Breaking-Event-Address:
 [<000003d9bd3c7f58>] __warn_printk+0xe8/0xf0

Cc: [email protected]
Reported-by: Christian Borntraeger <[email protected]>
Fixes: fe0ef00 ("KVM: s390: sort out physical vs virtual pointers usage")
Signed-off-by: Michael Mueller <[email protected]>
Tested-by: Christian Borntraeger <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Message-ID: <[email protected]>
Signed-off-by: Janosch Frank <[email protected]>
andy-shev pushed a commit that referenced this issue Aug 26, 2024
When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

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

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

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

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

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

   *** DEADLOCK ***

   May be due to missing lock nesting notation

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

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

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
andy-shev pushed a commit that referenced this issue Aug 26, 2024
Lockdep reported a warning in Linux version 6.6:

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

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

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

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

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

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
andy-shev pushed a commit that referenced this issue Aug 26, 2024
Currently, migrate_pages_batch() can lock multiple locked folios with an
arbitrary order.  Although folio_trylock() is used to avoid deadlock as
commit 2ef7dbb ("migrate_pages: try migrate in batch asynchronously
firstly") mentioned, it seems try_split_folio() is still missing.

It was found by compaction stress test when I explicitly enable EROFS
compressed files to use large folios, which case I cannot reproduce with
the same workload if large folio support is off (current mainline). 
Typically, filesystem reads (with locked file-backed folios) could use
another bdev/meta inode to load some other I/Os (e.g.  inode extent
metadata or caching compressed data), so the locking order will be:

  file-backed folios  (A)
     bdev/meta folios (B)

The following calltrace shows the deadlock:
   Thread 1 takes (B) lock and tries to take folio (A) lock
   Thread 2 takes (A) lock and tries to take folio (B) lock

[Thread 1]
INFO: task stress:1824 blocked for more than 30 seconds.
      Tainted: G           OE      6.10.0-rc7+ #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:stress          state:D stack:0     pid:1824  tgid:1824  ppid:1822   flags:0x0000000c
Call trace:
 __switch_to+0xec/0x138
 __schedule+0x43c/0xcb0
 schedule+0x54/0x198
 io_schedule+0x44/0x70
 folio_wait_bit_common+0x184/0x3f8
			<-- folio mapping ffff00036d69cb18 index 996  (**)
 __folio_lock+0x24/0x38
 migrate_pages_batch+0x77c/0xea0	// try_split_folio (mm/migrate.c:1486:2)
					// migrate_pages_batch (mm/migrate.c:1734:16)
		<--- LIST_HEAD(unmap_folios) has
			..
			folio mapping 0xffff0000d184f1d8 index 1711;   (*)
			folio mapping 0xffff0000d184f1d8 index 1712;
			..
 migrate_pages+0xb28/0xe90
 compact_zone+0xa08/0x10f0
 compact_node+0x9c/0x180
 sysctl_compaction_handler+0x8c/0x118
 proc_sys_call_handler+0x1a8/0x280
 proc_sys_write+0x1c/0x30
 vfs_write+0x240/0x380
 ksys_write+0x78/0x118
 __arm64_sys_write+0x24/0x38
 invoke_syscall+0x78/0x108
 el0_svc_common.constprop.0+0x48/0xf0
 do_el0_svc+0x24/0x38
 el0_svc+0x3c/0x148
 el0t_64_sync_handler+0x100/0x130
 el0t_64_sync+0x190/0x198

[Thread 2]
INFO: task stress:1825 blocked for more than 30 seconds.
      Tainted: G           OE      6.10.0-rc7+ #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:stress          state:D stack:0     pid:1825  tgid:1825  ppid:1822   flags:0x0000000c
Call trace:
 __switch_to+0xec/0x138
 __schedule+0x43c/0xcb0
 schedule+0x54/0x198
 io_schedule+0x44/0x70
 folio_wait_bit_common+0x184/0x3f8
			<-- folio = 0xfffffdffc6b503c0 (mapping == 0xffff0000d184f1d8 index == 1711) (*)
 __folio_lock+0x24/0x38
 z_erofs_runqueue+0x384/0x9c0 [erofs]
 z_erofs_readahead+0x21c/0x350 [erofs]       <-- folio mapping 0xffff00036d69cb18 range from [992, 1024] (**)
 read_pages+0x74/0x328
 page_cache_ra_order+0x26c/0x348
 ondemand_readahead+0x1c0/0x3a0
 page_cache_sync_ra+0x9c/0xc0
 filemap_get_pages+0xc4/0x708
 filemap_read+0x104/0x3a8
 generic_file_read_iter+0x4c/0x150
 vfs_read+0x27c/0x330
 ksys_pread64+0x84/0xd0
 __arm64_sys_pread64+0x28/0x40
 invoke_syscall+0x78/0x108
 el0_svc_common.constprop.0+0x48/0xf0
 do_el0_svc+0x24/0x38
 el0_svc+0x3c/0x148
 el0t_64_sync_handler+0x100/0x130
 el0t_64_sync+0x190/0x198

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5dfab10 ("migrate_pages: batch _unmap and _move")
Signed-off-by: Gao Xiang <[email protected]>
Reviewed-by: "Huang, Ying" <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
andy-shev pushed a commit that referenced this issue Aug 26, 2024
attempts to retrofit memory safety onto C are increasingly annoying

------------[ cut here ]------------
memcpy: detected field-spanning write (size 4) of single field "&k.replicas" at fs/bcachefs/replicas.c:454 (size 3)
WARNING: CPU: 5 PID: 6525 at fs/bcachefs/replicas.c:454 bch2_replicas_gc2+0x2cb/0x400 [bcachefs]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
Modules linked in: dm_mod tun nf_conntrack_netlink nfnetlink xt_addrtype br_netfilter overlay msr sctp bcachefs lz4hc_compress lz4_compress libcrc32c xor raid6_pq lz4_decompress pps_ldisc pps_core wireguard libchacha20poly1305 chacha_x86_64 poly1305_x86_64 ip6_udp_tunnel udp_tunnel curve25519_x86_64 libcurve25519_generic libchacha sit tunnel4 ip_tunnel af_packet bridge stp llc ip6table_nat ip6table_filter ip6_tables xt_MASQUERADE xt_conntrack iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables tcp_bbr sch_fq_codel efivarfs nls_iso8859_1 nls_cp437 vfat fat cdc_mbim cdc_wdm cdc_ncm cdc_ether usbnet r8152 input_leds joydev mii amdgpu mousedev hid_generic usbhid hid ath10k_pci amd_atl edac_mce_amd ath10k_core kvm_amd ath kvm mac80211 bfq crc32_pclmul crc32c_intel polyval_clmulni polyval_generic sha512_ssse3 sha256_ssse3 sha1_ssse3 snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg i2c_algo_bit drm_exec snd_hda_codec r8169 drm_suballoc_helper
aesni_intel gf128mul crypto_simd amdxcp realtek mfd_core tpm_crb drm_buddy snd_hwdep mdio_devres libarc4 cryptd tpm_tis wmi_bmof cfg80211 evdev libphy snd_hda_core tpm_tis_core gpu_sched rapl xhci_pci xhci_hcd snd_pcm drm_display_helper snd_timer tpm sp5100_tco rfkill efi_pstore mpt3sas drm_ttm_helper ahci usbcore libaescfb ccp snd ttm 8250 libahci watchdog soundcore raid_class sha1_generic acpi_cpufreq k10temp 8250_base usb_common scsi_transport_sas i2c_piix4 hwmon video serial_mctrl_gpio serial_base ecdh_generic wmi rtc_cmos backlight ecc gpio_amdpt rng_core gpio_generic button
CPU: 5 UID: 0 PID: 6525 Comm: bcachefs Tainted: G        W          6.11.0-rc1-ojab-00058-g224bc118aec9 #6 6d5debde398d2a84851f42ab300dae32c2992027
Tainted: [W]=WARN
RIP: 0010:bch2_replicas_gc2+0x2cb/0x400 [bcachefs]
Code: c7 c2 60 91 d1 c1 48 89 c6 48 c7 c7 98 91 d1 c1 4c 89 14 24 44 89 5c 24 08 48 89 44 24 20 c6 05 fa 68 04 00 01 e8 05 a3 40 e4 <0f> 0b 4c 8b 14 24 44 8b 5c 24 08 48 8b 44 24 20 e9 55 fe ff ff 8b
RSP: 0018:ffffb434c9263d60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9a8efa79cc00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffb434c9263de0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000005
R13: ffff9a8efa73c300 R14: ffff9a8d9e880000 R15: ffff9a8d9e8806f8
FS:  0000000000000000(0000) GS:ffff9a9410c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565423373090 CR3: 0000000164e30000 CR4: 00000000003506f0
Call Trace:
<TASK>
? __warn+0x97/0x150
? bch2_replicas_gc2+0x2cb/0x400 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
? report_bug+0x196/0x1c0
? handle_bug+0x3c/0x70
? exc_invalid_op+0x17/0x80
? __wake_up_klogd.part.0+0x4c/0x80
? asm_exc_invalid_op+0x16/0x20
? bch2_replicas_gc2+0x2cb/0x400 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_replicas_gc2+0x2cb/0x400:
bch2_replicas_gc2 at /home/ojab/src/bcachefs/fs/bcachefs/replicas.c:454 (discriminator 3)
? bch2_dev_usage_read+0xa0/0xa0 [bcachefs 9803eca5e131ef28f26250ede34072d5b50d98b3]
bch2_dev_usage_read+0xa0/0xa0:
discard_in_flight_remove at /home/ojab/src/bcachefs/fs/bcachefs/alloc_background.c:1712

Signed-off-by: Kent Overstreet <[email protected]>
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