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Fix build of 4.14 kernel in dunfell OE#4

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gratian merged 1 commit intoni:nilrt/master/4.14from
chaitu236:dev/fix_objtool_build
Aug 19, 2020
Merged

Fix build of 4.14 kernel in dunfell OE#4
gratian merged 1 commit intoni:nilrt/master/4.14from
chaitu236:dev/fix_objtool_build

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

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

commit f73b3cc upstream.

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

Clobber CFLAGS to ensure consistent objtool compilation behavior.

Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/83a276df209962e6058fcb6c615eef9d401c21bc.1567121311.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CC: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@chaitu236
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Ship it!

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

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

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

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

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

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

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

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

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

  other info that might help us debug this:

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

   Possible unsafe locking scenario:

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

   *** DEADLOCK ***

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

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

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

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

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

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

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

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

Which corresponds to:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      return ret

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

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

  $ drgn dump_block_groups.py

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

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

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

  other info that might help us debug this:

   Possible unsafe locking scenario:

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

   *** DEADLOCK ***

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

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

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

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

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

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

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

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

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

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

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

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

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

Stack unwinders may probe memory when looking for frames.

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

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

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

The full msan failure with track origins looks like:

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

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

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

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

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

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

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

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

dmatest:

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

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

Before:

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

After this patch:

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

After this patch and increase dma clk to 400MHz:

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

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

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

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

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

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

The following leaks were detected by ASAN:

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

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

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

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

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

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

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

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

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

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

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

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

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

[30129.876625]  Possible unsafe locking scenario:

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

[30129.876633]  *** DEADLOCK ***

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

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

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

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

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

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

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

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

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

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

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

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

  other info that might help us debug this:

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

   Possible unsafe locking scenario:

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

   *** DEADLOCK ***

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Fix the same by filtering with allowed AT91 SoC list.

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

commit 6808965 upstream.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Fixes: a8c66b6 ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <stable@vger.kernel.org> #4.0+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jpautler pushed a commit to jpautler/linux that referenced this pull request Nov 8, 2021
commit 57f0ff0 upstream.

It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  ni#1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  ni#2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  ni#3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  ni#4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  ni#5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  ni#6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  ni#7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  ni#8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  ni#9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  ni#10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  ni#11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  ni#12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  ni#13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  ni#14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  ni#15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  ni#16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  ni#17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  ni#18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame ni#2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
CC: Milian Wolff <milian.wolff@kdab.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com
Reported-by: Juri Lelli <jlelli@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jpautler pushed a commit to jpautler/linux that referenced this pull request Nov 8, 2021
[ Upstream commit 8f96a5b ]

We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed.  However we do this by re-opening the
block device and calling filp_update_time.  This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this.  Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0

but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> ni#4 (&lo->lo_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       lo_open+0x28/0x60 [loop]
       blkdev_get_whole+0x25/0xf0
       blkdev_get_by_dev.part.0+0x168/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       do_sys_openat2+0x7b/0x130
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> ni#3 (&disk->open_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7d/0x750
       blkdev_get_by_dev.part.0+0x56/0x3c0
       blkdev_open+0xd2/0xe0
       do_dentry_open+0x161/0x390
       path_openat+0x3cc/0xa20
       do_filp_open+0x96/0x120
       file_open_name+0xc7/0x170
       filp_open+0x2c/0x50
       btrfs_scratch_superblocks.part.0+0x10f/0x170
       btrfs_rm_device.cold+0xe8/0xed
       btrfs_ioctl+0x2a31/0x2e70
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> ni#2 (sb_writers#12){.+.+}-{0:0}:
       lo_write_bvec+0xc2/0x240 [loop]
       loop_process_work+0x238/0xd00 [loop]
       process_one_work+0x26b/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> ni#1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       process_one_work+0x245/0x560
       worker_thread+0x55/0x3c0
       kthread+0x140/0x160
       ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       __lock_acquire+0x10ea/0x1d90
       lock_acquire+0xb5/0x2b0
       flush_workqueue+0x91/0x5e0
       drain_workqueue+0xa0/0x110
       destroy_workqueue+0x36/0x250
       __loop_clr_fd+0x9a/0x660 [loop]
       block_ioctl+0x3f/0x50
       __x64_sys_ioctl+0x80/0xb0
       do_syscall_64+0x38/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

1 lock held by losetup/11596:
 #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]

stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack_lvl+0x57/0x72
 check_noncircular+0xcf/0xf0
 ? stack_trace_save+0x3b/0x50
 __lock_acquire+0x10ea/0x1d90
 lock_acquire+0xb5/0x2b0
 ? flush_workqueue+0x67/0x5e0
 ? lockdep_init_map_type+0x47/0x220
 flush_workqueue+0x91/0x5e0
 ? flush_workqueue+0x67/0x5e0
 ? verify_cpu+0xf0/0x100
 drain_workqueue+0xa0/0x110
 destroy_workqueue+0x36/0x250
 __loop_clr_fd+0x9a/0x660 [loop]
 ? blkdev_ioctl+0x8d/0x2a0
 block_ioctl+0x3f/0x50
 __x64_sys_ioctl+0x80/0xb0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jpautler pushed a commit to jpautler/linux that referenced this pull request Dec 8, 2021
[ Upstream commit 8ef9dc0 ]

We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc.  This was uncovered
by 87579e9 ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers.  The lockdep splat is as
follows:

  WARNING: possible circular locking dependency detected
  5.14.0-rc2-custom+ ni#34 Not tainted
  ------------------------------------------------------
  losetup/156417 is trying to acquire lock:
  ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600

  but task is already holding lock:
  ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> ni#5 (&lo->lo_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 lo_open+0x28/0x60 [loop]
	 blkdev_get_whole+0x28/0xf0
	 blkdev_get_by_dev.part.0+0x168/0x3c0
	 blkdev_open+0xd2/0xe0
	 do_dentry_open+0x163/0x3a0
	 path_openat+0x74d/0xa40
	 do_filp_open+0x9c/0x140
	 do_sys_openat2+0xb1/0x170
	 __x64_sys_openat+0x54/0x90
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> ni#4 (&disk->open_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 blkdev_get_by_dev.part.0+0xd1/0x3c0
	 blkdev_get_by_path+0xc0/0xd0
	 btrfs_scan_one_device+0x52/0x1f0 [btrfs]
	 btrfs_control_ioctl+0xac/0x170 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> ni#3 (uuid_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 btrfs_rm_device+0x48/0x6a0 [btrfs]
	 btrfs_ioctl+0x2d1c/0x3110 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> ni#2 (sb_writers#11){.+.+}-{0:0}:
	 lo_write_bvec+0x112/0x290 [loop]
	 loop_process_work+0x25f/0xcb0 [loop]
	 process_one_work+0x28f/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> ni#1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
	 process_one_work+0x266/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
	 __lock_acquire+0x1130/0x1dc0
	 lock_acquire+0xf5/0x320
	 flush_workqueue+0xae/0x600
	 drain_workqueue+0xa0/0x110
	 destroy_workqueue+0x36/0x250
	 __loop_clr_fd+0x9a/0x650 [loop]
	 lo_ioctl+0x29d/0x780 [loop]
	 block_ioctl+0x3f/0x50
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  other info that might help us debug this:
  Chain exists of:
    (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
   Possible unsafe locking scenario:
	 CPU0                    CPU1
	 ----                    ----
    lock(&lo->lo_mutex);
				 lock(&disk->open_mutex);
				 lock(&lo->lo_mutex);
    lock((wq_completion)loop0);

   *** DEADLOCK ***
  1 lock held by losetup/156417:
   #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  stack backtrace:
  CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ ni#34
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack_lvl+0x57/0x72
   check_noncircular+0x10a/0x120
   __lock_acquire+0x1130/0x1dc0
   lock_acquire+0xf5/0x320
   ? flush_workqueue+0x84/0x600
   flush_workqueue+0xae/0x600
   ? flush_workqueue+0x84/0x600
   drain_workqueue+0xa0/0x110
   destroy_workqueue+0x36/0x250
   __loop_clr_fd+0x9a/0x650 [loop]
   lo_ioctl+0x29d/0x780 [loop]
   ? __lock_acquire+0x3a0/0x1dc0
   ? update_dl_rq_load_avg+0x152/0x360
   ? lock_is_held_type+0xa5/0x120
   ? find_held_lock.constprop.0+0x2b/0x80
   block_ioctl+0x3f/0x50
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f645884de6b

Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid.  In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.

However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.

We don't need the uuid mutex here however.  If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open.  If we call it after the scratch happens it will
not appear to be a valid btrfs file system.

We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.

So drop the uuid_mutex here in order to fix the lockdep splat.

A more detailed explanation from the discussion:

We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.

We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.

The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.

Scan will call device_list_add() with the device we're removing.  We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID.  At this point we lock the fs_devices->device_list_mutex.  This is
what protects us in this case, but we have two cases here.

1. We aren't to the device removal part of the RM.  We found our device,
   and device name matches our path, we go down and we set total_devices
   to our super number of devices, which doesn't affect anything because
   we haven't done the remove yet.

2. We are past the device removal part, which is protected by the
   device_list_mutex.  Scan doesn't find the device, it goes down and
   does the

   if (fs_devices->opened)
	   return -EBUSY;

   check and we bail out.

Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more from the discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jpautler pushed a commit to jpautler/linux that referenced this pull request Dec 8, 2021
[ Upstream commit f0caea8 ]

Olga reports seeing the following Oops when doing O_DIRECT writes to a
pNFS flexfiles server:

Oops: 0000 [ni#1] SMP PTI
CPU: 1 PID: 234186 Comm: kworker/u8:1 Not tainted 5.15.0-rc4+ ni#4
Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
Workqueue: nfsiod rpc_async_release [sunrpc]
RIP: 0010:nfs_mark_request_commit+0x12/0x30 [nfs]
Code: ff ff be 03 00 00 00 e8 ac 34 83 eb e9 29 ff ff
ff e8 22 bc d7 eb 66 90 0f 1f 44 00 00 48 85 f6 74 16 48 8b 42 10 48
8b 40 18 <48> 8b 40 18 48 85 c0 74 05 e9 70 fc 15 ec 48 89 d6 e9 68 ed
ff ff
RSP: 0018:ffffa82f0159fe00 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8f3393141880 RCX: 0000000000000000
RDX: ffffa82f0159fe08 RSI: ffff8f3381252500 RDI: ffff8f3393141880
RBP: ffff8f33ac317c00 R08: 0000000000000000 R09: ffff8f3487724cb0
R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000001
R13: ffff8f3485bccee0 R14: ffff8f33ac317c10 R15: ffff8f33ac317cd8
FS:  0000000000000000(0000) GS:ffff8f34fbc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 0000000122120006 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 nfs_direct_write_completion+0x13b/0x250 [nfs]
 rpc_free_task+0x39/0x60 [sunrpc]
 rpc_async_release+0x29/0x40 [sunrpc]
 process_one_work+0x1ce/0x370
 worker_thread+0x30/0x380
 ? process_one_work+0x370/0x370
 kthread+0x11a/0x140
 ? set_kthread_struct+0x40/0x40
 ret_from_fork+0x22/0x30

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 9c455a8 ("NFS/pNFS: Clean up pNFS commit operations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jpautler pushed a commit to jpautler/linux that referenced this pull request Dec 8, 2021
[ Upstream commit 54659ca ]

when turning off a connection, lockdep complains with the
following warning (a modprobe has been done but the same
happens with a disconnection from NetworkManager,
it's enough to trigger a cfg80211_disconnect call):

[  682.855867] ======================================================
[  682.855877] WARNING: possible circular locking dependency detected
[  682.855887] 5.14.0-rc6+ ni#16 Tainted: G         C OE
[  682.855898] ------------------------------------------------------
[  682.855906] modprobe/1770 is trying to acquire lock:
[  682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2},
		at: rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.856073]
               but task is already holding lock:
[  682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.856207]
               which lock already depends on the new lock.

[  682.856215]
               the existing dependency chain (in reverse order) is:
[  682.856223]
               -> ni#1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}:
[  682.856247]        _raw_spin_lock_bh+0x34/0x40
[  682.856265]        rtw_get_stainfo+0x9a/0x110 [r8723bs]
[  682.856389]        rtw_xmit_classifier+0x27/0x130 [r8723bs]
[  682.856515]        rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[  682.856642]        rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs]
[  682.856752]        rtw_xmit+0x4ef/0x890 [r8723bs]
[  682.856879]        _rtw_xmit_entry+0xba/0x350 [r8723bs]
[  682.856981]        dev_hard_start_xmit+0xee/0x320
[  682.856999]        sch_direct_xmit+0x8c/0x330
[  682.857014]        __dev_queue_xmit+0xba5/0xf00
[  682.857030]        packet_sendmsg+0x981/0x1b80
[  682.857047]        sock_sendmsg+0x5b/0x60
[  682.857060]        __sys_sendto+0xf1/0x160
[  682.857073]        __x64_sys_sendto+0x24/0x30
[  682.857087]        do_syscall_64+0x3a/0x80
[  682.857102]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.857117]
               -> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[  682.857142]        __lock_acquire+0xfd9/0x1b50
[  682.857158]        lock_acquire+0xb4/0x2c0
[  682.857172]        _raw_spin_lock_bh+0x34/0x40
[  682.857185]        rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.857308]        rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.857415]        cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.857522]        cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.857759]        cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.857961]        cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.858163]        raw_notifier_call_chain+0x41/0x50
[  682.858180]        __dev_close_many+0x62/0x100
[  682.858195]        dev_close_many+0x7d/0x120
[  682.858209]        unregister_netdevice_many+0x416/0x680
[  682.858225]        unregister_netdevice_queue+0xab/0xf0
[  682.858240]        unregister_netdev+0x18/0x20
[  682.858255]        rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.858360]        rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.858463]        sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.858532]        device_release_driver_internal+0xf7/0x1d0
[  682.858550]        driver_detach+0x47/0x90
[  682.858564]        bus_remove_driver+0x77/0xd0
[  682.858579]        rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.858685]        __x64_sys_delete_module+0x13f/0x250
[  682.858699]        do_syscall_64+0x3a/0x80
[  682.858715]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.858729]
               other info that might help us debug this:

[  682.858737]  Possible unsafe locking scenario:

[  682.858744]        CPU0                    CPU1
[  682.858751]        ----                    ----
[  682.858758]   lock(&pstapriv->sta_hash_lock);
[  682.858772]                                lock(&pxmitpriv->lock);
[  682.858786]                                lock(&pstapriv->sta_hash_lock);
[  682.858799]   lock(&pxmitpriv->lock);
[  682.858812]
                *** DEADLOCK ***

[  682.858820] 5 locks held by modprobe/1770:
[  682.858831]  #0: ffff8d870697d980 (&dev->mutex){....}-{3:3},
		at: device_release_driver_internal+0x1a/0x1d0
[  682.858869]  ni#1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3},
		at: unregister_netdev+0xe/0x20
[  682.858906]  ni#2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3},
		at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211]
[  682.859131]  ni#3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3},
		at: cfg80211_leave+0x20/0x40 [cfg80211]
[  682.859354]  ni#4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.859482]
               stack backtrace:
[  682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G
		C OE     5.14.0-rc6+ ni#16
[  682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015
[  682.859517] Call Trace:
[  682.859531]  dump_stack_lvl+0x56/0x6f
[  682.859551]  check_noncircular+0xdb/0xf0
[  682.859579]  __lock_acquire+0xfd9/0x1b50
[  682.859606]  lock_acquire+0xb4/0x2c0
[  682.859623]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.859752]  ? mark_held_locks+0x48/0x70
[  682.859769]  ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs]
[  682.859898]  _raw_spin_lock_bh+0x34/0x40
[  682.859914]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860039]  rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860171]  rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.860286]  cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.860397]  cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.860629]  cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.860836]  cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.861048]  ? __lock_acquire+0x4dc/0x1b50
[  682.861070]  ? lock_is_held_type+0xa8/0x110
[  682.861089]  ? lock_is_held_type+0xa8/0x110
[  682.861104]  ? find_held_lock+0x2d/0x90
[  682.861120]  ? packet_notifier+0x173/0x300
[  682.861141]  ? lock_release+0xb3/0x250
[  682.861160]  ? packet_notifier+0x192/0x300
[  682.861184]  raw_notifier_call_chain+0x41/0x50
[  682.861205]  __dev_close_many+0x62/0x100
[  682.861224]  dev_close_many+0x7d/0x120
[  682.861245]  unregister_netdevice_many+0x416/0x680
[  682.861264]  ? find_held_lock+0x2d/0x90
[  682.861284]  unregister_netdevice_queue+0xab/0xf0
[  682.861306]  unregister_netdev+0x18/0x20
[  682.861325]  rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.861434]  rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.861542]  sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.861615]  device_release_driver_internal+0xf7/0x1d0
[  682.861637]  driver_detach+0x47/0x90
[  682.861656]  bus_remove_driver+0x77/0xd0
[  682.861674]  rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.861782]  __x64_sys_delete_module+0x13f/0x250
[  682.861801]  ? lockdep_hardirqs_on_prepare+0xf3/0x170
[  682.861817]  ? syscall_enter_from_user_mode+0x20/0x70
[  682.861836]  do_syscall_64+0x3a/0x80
[  682.861855]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.861873] RIP: 0033:0x7f6dbe85400b
[  682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa
b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d
1e 0c 00 f7 d8 64 89 01 48
[  682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b
[  682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88
[  682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000
[  682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88
[  682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848

This happens because when we enqueue a frame for
transmission we do it under xmit_priv lock, then calling
rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock
and this leads to the following lock dependency:

xmit_priv->lock -> sta_hash_lock

Turning off a connection will bring to call
rtw_free_assoc_resources which will set up
the inverse dependency:

sta_hash_lock -> xmit_priv_lock

This could lead to a deadlock as lockdep complains.

Fix it by removing the xmit_priv->lock around
rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit
and put it in a smaller critical section inside
rtw_xmit_classifier, the only place where
xmit_priv data are actually accessed.

Replace spin_{lock,unlock}_bh(pxmitpriv->lock)
in other tx paths leading to rtw_xmitframe_enqueue
call with spin_{lock,unlock}_bh(psta->sleep_q.lock)
- it's not clear why accessing a sleep_q was protected
by a spinlock on xmitpriv->lock.

This way is avoided the same faulty lock nesting
order.

Extra changes in v2 by Hans de Goede:
-Lift the taking of the struct __queue.lock spinlock out of
 rtw_free_xmitframe_queue() into the callers this allows also
 protecting a bunch of related state in rtw_free_stainfo():
-Protect psta->sleepq_len on rtw_free_xmitframe_queue(&psta->sleep_q);
-Protect struct tx_servq.tx_pending and tx_servq.qcnt when
 calling rtw_free_xmitframe_queue(&tx_servq.sta_pending)
-This also allows moving the spin_lock_bh(&pxmitpriv->lock); to below
 the sleep_q free-ing code, avoiding another ABBA locking issue

CC: Larry Finger <Larry.Finger@lwfinger.net>
Co-developed-by: Hans de Goede <hdegoede@redhat.com>
Tested-on: Lenovo Ideapad MiiX 300-10IBY
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210920145502.155454-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2021
[ Upstream commit 8ef9dc0 ]

We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc.  This was uncovered
by 87579e9 ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers.  The lockdep splat is as
follows:

  WARNING: possible circular locking dependency detected
  5.14.0-rc2-custom+ ni#34 Not tainted
  ------------------------------------------------------
  losetup/156417 is trying to acquire lock:
  ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600

  but task is already holding lock:
  ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #5 (&lo->lo_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 lo_open+0x28/0x60 [loop]
	 blkdev_get_whole+0x28/0xf0
	 blkdev_get_by_dev.part.0+0x168/0x3c0
	 blkdev_open+0xd2/0xe0
	 do_dentry_open+0x163/0x3a0
	 path_openat+0x74d/0xa40
	 do_filp_open+0x9c/0x140
	 do_sys_openat2+0xb1/0x170
	 __x64_sys_openat+0x54/0x90
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #4 (&disk->open_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 blkdev_get_by_dev.part.0+0xd1/0x3c0
	 blkdev_get_by_path+0xc0/0xd0
	 btrfs_scan_one_device+0x52/0x1f0 [btrfs]
	 btrfs_control_ioctl+0xac/0x170 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #3 (uuid_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 btrfs_rm_device+0x48/0x6a0 [btrfs]
	 btrfs_ioctl+0x2d1c/0x3110 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #2 (sb_writers#11){.+.+}-{0:0}:
	 lo_write_bvec+0x112/0x290 [loop]
	 loop_process_work+0x25f/0xcb0 [loop]
	 process_one_work+0x28f/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
	 process_one_work+0x266/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
	 __lock_acquire+0x1130/0x1dc0
	 lock_acquire+0xf5/0x320
	 flush_workqueue+0xae/0x600
	 drain_workqueue+0xa0/0x110
	 destroy_workqueue+0x36/0x250
	 __loop_clr_fd+0x9a/0x650 [loop]
	 lo_ioctl+0x29d/0x780 [loop]
	 block_ioctl+0x3f/0x50
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  other info that might help us debug this:
  Chain exists of:
    (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
   Possible unsafe locking scenario:
	 CPU0                    CPU1
	 ----                    ----
    lock(&lo->lo_mutex);
				 lock(&disk->open_mutex);
				 lock(&lo->lo_mutex);
    lock((wq_completion)loop0);

   *** DEADLOCK ***
  1 lock held by losetup/156417:
   #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  stack backtrace:
  CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ ni#34
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack_lvl+0x57/0x72
   check_noncircular+0x10a/0x120
   __lock_acquire+0x1130/0x1dc0
   lock_acquire+0xf5/0x320
   ? flush_workqueue+0x84/0x600
   flush_workqueue+0xae/0x600
   ? flush_workqueue+0x84/0x600
   drain_workqueue+0xa0/0x110
   destroy_workqueue+0x36/0x250
   __loop_clr_fd+0x9a/0x650 [loop]
   lo_ioctl+0x29d/0x780 [loop]
   ? __lock_acquire+0x3a0/0x1dc0
   ? update_dl_rq_load_avg+0x152/0x360
   ? lock_is_held_type+0xa5/0x120
   ? find_held_lock.constprop.0+0x2b/0x80
   block_ioctl+0x3f/0x50
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f645884de6b

Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid.  In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.

However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.

We don't need the uuid mutex here however.  If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open.  If we call it after the scratch happens it will
not appear to be a valid btrfs file system.

We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.

So drop the uuid_mutex here in order to fix the lockdep splat.

A more detailed explanation from the discussion:

We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.

We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.

The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.

Scan will call device_list_add() with the device we're removing.  We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID.  At this point we lock the fs_devices->device_list_mutex.  This is
what protects us in this case, but we have two cases here.

1. We aren't to the device removal part of the RM.  We found our device,
   and device name matches our path, we go down and we set total_devices
   to our super number of devices, which doesn't affect anything because
   we haven't done the remove yet.

2. We are past the device removal part, which is protected by the
   device_list_mutex.  Scan doesn't find the device, it goes down and
   does the

   if (fs_devices->opened)
	   return -EBUSY;

   check and we bail out.

Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more from the discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2021
[ Upstream commit f0caea8 ]

Olga reports seeing the following Oops when doing O_DIRECT writes to a
pNFS flexfiles server:

Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 234186 Comm: kworker/u8:1 Not tainted 5.15.0-rc4+ #4
Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
Workqueue: nfsiod rpc_async_release [sunrpc]
RIP: 0010:nfs_mark_request_commit+0x12/0x30 [nfs]
Code: ff ff be 03 00 00 00 e8 ac 34 83 eb e9 29 ff ff
ff e8 22 bc d7 eb 66 90 0f 1f 44 00 00 48 85 f6 74 16 48 8b 42 10 48
8b 40 18 <48> 8b 40 18 48 85 c0 74 05 e9 70 fc 15 ec 48 89 d6 e9 68 ed
ff ff
RSP: 0018:ffffa82f0159fe00 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8f3393141880 RCX: 0000000000000000
RDX: ffffa82f0159fe08 RSI: ffff8f3381252500 RDI: ffff8f3393141880
RBP: ffff8f33ac317c00 R08: 0000000000000000 R09: ffff8f3487724cb0
R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000001
R13: ffff8f3485bccee0 R14: ffff8f33ac317c10 R15: ffff8f33ac317cd8
FS:  0000000000000000(0000) GS:ffff8f34fbc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 0000000122120006 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 nfs_direct_write_completion+0x13b/0x250 [nfs]
 rpc_free_task+0x39/0x60 [sunrpc]
 rpc_async_release+0x29/0x40 [sunrpc]
 process_one_work+0x1ce/0x370
 worker_thread+0x30/0x380
 ? process_one_work+0x370/0x370
 kthread+0x11a/0x140
 ? set_kthread_struct+0x40/0x40
 ret_from_fork+0x22/0x30

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 9c455a8 ("NFS/pNFS: Clean up pNFS commit operations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2021
[ Upstream commit 5ec0a6f ]

Host crashes when pci_enable_atomic_ops_to_root() is called for VFs with
virtual buses. The virtual buses added to SR-IOV have bus->self set to NULL
and host crashes due to this.

  PID: 4481   TASK: ffff89c6941b0000  CPU: 53  COMMAND: "bash"
  ...
   #3 [ffff9a9481713808] oops_end at ffffffffb9025cd6
   #4 [ffff9a9481713828] page_fault_oops at ffffffffb906e417
   #5 [ffff9a9481713888] exc_page_fault at ffffffffb9a0ad14
   ni#6 [ffff9a94817138b0] asm_exc_page_fault at ffffffffb9c00ace
      [exception RIP: pcie_capability_read_dword+28]
      RIP: ffffffffb952fd5c  RSP: ffff9a9481713960  RFLAGS: 00010246
      RAX: 0000000000000001  RBX: ffff89c6b1096000  RCX: 0000000000000000
      RDX: ffff9a9481713990  RSI: 0000000000000024  RDI: 0000000000000000
      RBP: 0000000000000080   R8: 0000000000000008   R9: ffff89c64341a2f8
      R10: 0000000000000002  R11: 0000000000000000  R12: ffff89c648bab000
      R13: 0000000000000000  R14: 0000000000000000  R15: ffff89c648bab0c8
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   ni#7 [ffff9a9481713988] pci_enable_atomic_ops_to_root at ffffffffb95359a6
   ni#8 [ffff9a94817139c0] bnxt_qplib_determine_atomics at ffffffffc08c1a33 [bnxt_re]
   ni#9 [ffff9a94817139d0] bnxt_re_dev_init at ffffffffc08ba2d1 [bnxt_re]

Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit in Device
Control 2 is reserved for VFs.  The PF value applies to all associated VFs.

Return -EINVAL if pci_enable_atomic_ops_to_root() is called for a VF.

Link: https://lore.kernel.org/r/1631354585-16597-1-git-send-email-selvin.xavier@broadcom.com
Fixes: 35f5ace ("RDMA/bnxt_re: Enable global atomic ops if platform supports")
Fixes: 430a236 ("PCI: Add pci_enable_atomic_ops_to_root()")
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Dec 8, 2021
commit 2aa3660 upstream.

It is generally unsafe to call put_device() with dpm_list_mtx held,
because the given device's release routine may carry out an action
depending on that lock which then may deadlock, so modify the
system-wide suspend and resume of devices to always drop dpm_list_mtx
before calling put_device() (and adjust white space somewhat while
at it).

For instance, this prevents the following splat from showing up in
the kernel log after a system resume in certain configurations:

[ 3290.969514] ======================================================
[ 3290.969517] WARNING: possible circular locking dependency detected
[ 3290.969519] 5.15.0+ #2420 Tainted: G S
[ 3290.969523] ------------------------------------------------------
[ 3290.969525] systemd-sleep/4553 is trying to acquire lock:
[ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0
[ 3290.969554]
               but task is already holding lock:
[ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.969571]
               which lock already depends on the new lock.

[ 3290.969573]
               the existing dependency chain (in reverse order) is:
[ 3290.969575]
               -> #3 (dpm_list_mtx){+.+.}-{3:3}:
[ 3290.969583]        __mutex_lock+0x9d/0xa30
[ 3290.969591]        device_pm_add+0x2e/0xe0
[ 3290.969597]        device_add+0x4d5/0x8f0
[ 3290.969605]        hci_conn_add_sysfs+0x43/0xb0 [bluetooth]
[ 3290.969689]        hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth]
[ 3290.969747]        hci_event_packet+0xd6c/0x28a0 [bluetooth]
[ 3290.969798]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969842]        process_one_work+0x2aa/0x650
[ 3290.969851]        worker_thread+0x39/0x400
[ 3290.969859]        kthread+0x142/0x170
[ 3290.969865]        ret_from_fork+0x22/0x30
[ 3290.969872]
               -> #2 (&hdev->lock){+.+.}-{3:3}:
[ 3290.969881]        __mutex_lock+0x9d/0xa30
[ 3290.969887]        hci_event_packet+0xba/0x28a0 [bluetooth]
[ 3290.969935]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969978]        process_one_work+0x2aa/0x650
[ 3290.969985]        worker_thread+0x39/0x400
[ 3290.969993]        kthread+0x142/0x170
[ 3290.969999]        ret_from_fork+0x22/0x30
[ 3290.970004]
               -> #1 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}:
[ 3290.970013]        process_one_work+0x27d/0x650
[ 3290.970020]        worker_thread+0x39/0x400
[ 3290.970028]        kthread+0x142/0x170
[ 3290.970033]        ret_from_fork+0x22/0x30
[ 3290.970038]
               -> #0 ((wq_completion)hci0#2){+.+.}-{0:0}:
[ 3290.970047]        __lock_acquire+0x15cb/0x1b50
[ 3290.970054]        lock_acquire+0x26c/0x300
[ 3290.970059]        flush_workqueue+0xae/0x4a0
[ 3290.970066]        drain_workqueue+0xa1/0x130
[ 3290.970073]        destroy_workqueue+0x34/0x1f0
[ 3290.970081]        hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970130]        bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970195]        device_release+0x33/0x90
[ 3290.970201]        kobject_release+0x63/0x160
[ 3290.970211]        dpm_resume+0x164/0x3e0
[ 3290.970215]        dpm_resume_end+0xd/0x20
[ 3290.970220]        suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970229]        pm_suspend+0x26b/0x310
[ 3290.970236]        state_store+0x42/0x90
[ 3290.970243]        kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970251]        new_sync_write+0x125/0x1c0
[ 3290.970257]        vfs_write+0x360/0x3c0
[ 3290.970263]        ksys_write+0xa7/0xe0
[ 3290.970269]        do_syscall_64+0x3a/0x80
[ 3290.970276]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970284]
               other info that might help us debug this:

[ 3290.970285] Chain exists of:
                 (wq_completion)hci0#2 --> &hdev->lock --> dpm_list_mtx

[ 3290.970297]  Possible unsafe locking scenario:

[ 3290.970299]        CPU0                    CPU1
[ 3290.970300]        ----                    ----
[ 3290.970302]   lock(dpm_list_mtx);
[ 3290.970306]                                lock(&hdev->lock);
[ 3290.970310]                                lock(dpm_list_mtx);
[ 3290.970314]   lock((wq_completion)hci0#2);
[ 3290.970319]
                *** DEADLOCK ***

[ 3290.970321] 7 locks held by systemd-sleep/4553:
[ 3290.970325]  #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0
[ 3290.970341]  #1: ffff888115a14488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0
[ 3290.970355]  #2: ffff888100f719e0 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0
[ 3290.970369]  #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90
[ 3290.970384]  #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310
[ 3290.970399]  #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80
[ 3290.970416]  ni#6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.970428]
               stack backtrace:
[ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S                5.15.0+ #2420
[ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019
[ 3290.970441] Call Trace:
[ 3290.970446]  dump_stack_lvl+0x44/0x57
[ 3290.970454]  check_noncircular+0x105/0x120
[ 3290.970468]  ? __lock_acquire+0x15cb/0x1b50
[ 3290.970474]  __lock_acquire+0x15cb/0x1b50
[ 3290.970487]  lock_acquire+0x26c/0x300
[ 3290.970493]  ? flush_workqueue+0x87/0x4a0
[ 3290.970503]  ? __raw_spin_lock_init+0x3b/0x60
[ 3290.970510]  ? lockdep_init_map_type+0x58/0x240
[ 3290.970519]  flush_workqueue+0xae/0x4a0
[ 3290.970526]  ? flush_workqueue+0x87/0x4a0
[ 3290.970544]  ? drain_workqueue+0xa1/0x130
[ 3290.970552]  drain_workqueue+0xa1/0x130
[ 3290.970561]  destroy_workqueue+0x34/0x1f0
[ 3290.970572]  hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970624]  bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970687]  device_release+0x33/0x90
[ 3290.970695]  kobject_release+0x63/0x160
[ 3290.970705]  dpm_resume+0x164/0x3e0
[ 3290.970710]  ? dpm_resume_early+0x251/0x3b0
[ 3290.970718]  dpm_resume_end+0xd/0x20
[ 3290.970723]  suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970737]  pm_suspend+0x26b/0x310
[ 3290.970746]  state_store+0x42/0x90
[ 3290.970755]  kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970764]  new_sync_write+0x125/0x1c0
[ 3290.970777]  vfs_write+0x360/0x3c0
[ 3290.970785]  ksys_write+0xa7/0xe0
[ 3290.970794]  do_syscall_64+0x3a/0x80
[ 3290.970803]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970811] RIP: 0033:0x7f41b1328164
[ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164
[ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004
[ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0
[ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004
[ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004

Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Dec 8, 2021
[ Upstream commit 54659ca ]

when turning off a connection, lockdep complains with the
following warning (a modprobe has been done but the same
happens with a disconnection from NetworkManager,
it's enough to trigger a cfg80211_disconnect call):

[  682.855867] ======================================================
[  682.855877] WARNING: possible circular locking dependency detected
[  682.855887] 5.14.0-rc6+ ni#16 Tainted: G         C OE
[  682.855898] ------------------------------------------------------
[  682.855906] modprobe/1770 is trying to acquire lock:
[  682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2},
		at: rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.856073]
               but task is already holding lock:
[  682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.856207]
               which lock already depends on the new lock.

[  682.856215]
               the existing dependency chain (in reverse order) is:
[  682.856223]
               -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}:
[  682.856247]        _raw_spin_lock_bh+0x34/0x40
[  682.856265]        rtw_get_stainfo+0x9a/0x110 [r8723bs]
[  682.856389]        rtw_xmit_classifier+0x27/0x130 [r8723bs]
[  682.856515]        rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[  682.856642]        rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs]
[  682.856752]        rtw_xmit+0x4ef/0x890 [r8723bs]
[  682.856879]        _rtw_xmit_entry+0xba/0x350 [r8723bs]
[  682.856981]        dev_hard_start_xmit+0xee/0x320
[  682.856999]        sch_direct_xmit+0x8c/0x330
[  682.857014]        __dev_queue_xmit+0xba5/0xf00
[  682.857030]        packet_sendmsg+0x981/0x1b80
[  682.857047]        sock_sendmsg+0x5b/0x60
[  682.857060]        __sys_sendto+0xf1/0x160
[  682.857073]        __x64_sys_sendto+0x24/0x30
[  682.857087]        do_syscall_64+0x3a/0x80
[  682.857102]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.857117]
               -> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[  682.857142]        __lock_acquire+0xfd9/0x1b50
[  682.857158]        lock_acquire+0xb4/0x2c0
[  682.857172]        _raw_spin_lock_bh+0x34/0x40
[  682.857185]        rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.857308]        rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.857415]        cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.857522]        cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.857759]        cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.857961]        cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.858163]        raw_notifier_call_chain+0x41/0x50
[  682.858180]        __dev_close_many+0x62/0x100
[  682.858195]        dev_close_many+0x7d/0x120
[  682.858209]        unregister_netdevice_many+0x416/0x680
[  682.858225]        unregister_netdevice_queue+0xab/0xf0
[  682.858240]        unregister_netdev+0x18/0x20
[  682.858255]        rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.858360]        rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.858463]        sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.858532]        device_release_driver_internal+0xf7/0x1d0
[  682.858550]        driver_detach+0x47/0x90
[  682.858564]        bus_remove_driver+0x77/0xd0
[  682.858579]        rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.858685]        __x64_sys_delete_module+0x13f/0x250
[  682.858699]        do_syscall_64+0x3a/0x80
[  682.858715]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.858729]
               other info that might help us debug this:

[  682.858737]  Possible unsafe locking scenario:

[  682.858744]        CPU0                    CPU1
[  682.858751]        ----                    ----
[  682.858758]   lock(&pstapriv->sta_hash_lock);
[  682.858772]                                lock(&pxmitpriv->lock);
[  682.858786]                                lock(&pstapriv->sta_hash_lock);
[  682.858799]   lock(&pxmitpriv->lock);
[  682.858812]
                *** DEADLOCK ***

[  682.858820] 5 locks held by modprobe/1770:
[  682.858831]  #0: ffff8d870697d980 (&dev->mutex){....}-{3:3},
		at: device_release_driver_internal+0x1a/0x1d0
[  682.858869]  #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3},
		at: unregister_netdev+0xe/0x20
[  682.858906]  #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3},
		at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211]
[  682.859131]  #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3},
		at: cfg80211_leave+0x20/0x40 [cfg80211]
[  682.859354]  #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.859482]
               stack backtrace:
[  682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G
		C OE     5.14.0-rc6+ ni#16
[  682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015
[  682.859517] Call Trace:
[  682.859531]  dump_stack_lvl+0x56/0x6f
[  682.859551]  check_noncircular+0xdb/0xf0
[  682.859579]  __lock_acquire+0xfd9/0x1b50
[  682.859606]  lock_acquire+0xb4/0x2c0
[  682.859623]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.859752]  ? mark_held_locks+0x48/0x70
[  682.859769]  ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs]
[  682.859898]  _raw_spin_lock_bh+0x34/0x40
[  682.859914]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860039]  rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860171]  rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.860286]  cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.860397]  cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.860629]  cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.860836]  cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.861048]  ? __lock_acquire+0x4dc/0x1b50
[  682.861070]  ? lock_is_held_type+0xa8/0x110
[  682.861089]  ? lock_is_held_type+0xa8/0x110
[  682.861104]  ? find_held_lock+0x2d/0x90
[  682.861120]  ? packet_notifier+0x173/0x300
[  682.861141]  ? lock_release+0xb3/0x250
[  682.861160]  ? packet_notifier+0x192/0x300
[  682.861184]  raw_notifier_call_chain+0x41/0x50
[  682.861205]  __dev_close_many+0x62/0x100
[  682.861224]  dev_close_many+0x7d/0x120
[  682.861245]  unregister_netdevice_many+0x416/0x680
[  682.861264]  ? find_held_lock+0x2d/0x90
[  682.861284]  unregister_netdevice_queue+0xab/0xf0
[  682.861306]  unregister_netdev+0x18/0x20
[  682.861325]  rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.861434]  rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.861542]  sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.861615]  device_release_driver_internal+0xf7/0x1d0
[  682.861637]  driver_detach+0x47/0x90
[  682.861656]  bus_remove_driver+0x77/0xd0
[  682.861674]  rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.861782]  __x64_sys_delete_module+0x13f/0x250
[  682.861801]  ? lockdep_hardirqs_on_prepare+0xf3/0x170
[  682.861817]  ? syscall_enter_from_user_mode+0x20/0x70
[  682.861836]  do_syscall_64+0x3a/0x80
[  682.861855]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.861873] RIP: 0033:0x7f6dbe85400b
[  682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa
b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d
1e 0c 00 f7 d8 64 89 01 48
[  682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b
[  682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88
[  682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000
[  682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88
[  682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848

This happens because when we enqueue a frame for
transmission we do it under xmit_priv lock, then calling
rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock
and this leads to the following lock dependency:

xmit_priv->lock -> sta_hash_lock

Turning off a connection will bring to call
rtw_free_assoc_resources which will set up
the inverse dependency:

sta_hash_lock -> xmit_priv_lock

This could lead to a deadlock as lockdep complains.

Fix it by removing the xmit_priv->lock around
rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit
and put it in a smaller critical section inside
rtw_xmit_classifier, the only place where
xmit_priv data are actually accessed.

Replace spin_{lock,unlock}_bh(pxmitpriv->lock)
in other tx paths leading to rtw_xmitframe_enqueue
call with spin_{lock,unlock}_bh(psta->sleep_q.lock)
- it's not clear why accessing a sleep_q was protected
by a spinlock on xmitpriv->lock.

This way is avoided the same faulty lock nesting
order.

Extra changes in v2 by Hans de Goede:
-Lift the taking of the struct __queue.lock spinlock out of
 rtw_free_xmitframe_queue() into the callers this allows also
 protecting a bunch of related state in rtw_free_stainfo():
-Protect psta->sleepq_len on rtw_free_xmitframe_queue(&psta->sleep_q);
-Protect struct tx_servq.tx_pending and tx_servq.qcnt when
 calling rtw_free_xmitframe_queue(&tx_servq.sta_pending)
-This also allows moving the spin_lock_bh(&pxmitpriv->lock); to below
 the sleep_q free-ing code, avoiding another ABBA locking issue

CC: Larry Finger <Larry.Finger@lwfinger.net>
Co-developed-by: Hans de Goede <hdegoede@redhat.com>
Tested-on: Lenovo Ideapad MiiX 300-10IBY
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210920145502.155454-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request Jan 12, 2022
commit f35838a upstream.

Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8 ("btrfs: Properly handle backref_in_log retval")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 12, 2022
commit f35838a upstream.

Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8 ("btrfs: Properly handle backref_in_log retval")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 12, 2022
commit 0c8e32f upstream.

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
  #1  0x0000557fc7b74f92 in perf_data__close (data=data@entry=0x7ffcdafa6578) at util/data.c:376
  #2  0x0000557fc7a6b807 in cmd_inject (argc=<optimized out>, argv=<optimized out>) at builtin-inject.c:1085
  #3  0x0000557fc7ac4783 in run_builtin (p=0x557fc8074878 <commands+600>, argc=4, argv=0x7ffcdafb6a60) at perf.c:313
  #4  0x0000557fc7a25d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  #5  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  #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 <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211213084829.114772-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Jan 12, 2022
commit c271a55 upstream.

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
  #1  0x00005621e48dd987 in perf_data__fd (data=0x7fff4c68bd08) at util/data.h:72
  #2  perf_data__fd (data=0x7fff4c68bd08) at util/data.h:69
  #3  cmd_inject (argc=<optimized out>, argv=0x7fff4c69c1f0) at builtin-inject.c:1017
  #4  0x00005621e4936783 in run_builtin (p=0x5621e4ee6878 <commands+600>, argc=4, argv=0x7fff4c69c1f0) at perf.c:313
  #5  0x00005621e4897d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  #6  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  #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 <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211213084829.114772-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 2, 2022
commit 232796d upstream.

When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:

- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;

- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.

This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.

Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.

When this deadlock happens, it produces a trace like the following:

  INFO: task syz-executor:25604 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
  btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
  btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
  btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f86920b2c4d
  RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
  RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
  RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
  R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
  INFO: task syz-executor:25628 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
  __mutex_lock_common kernel/locking/mutex.c:669 [inline]
  __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
  btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
  btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
  btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: stable@vger.kernel.org # 4.19
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 10, 2022
commit 8b59b0a upstream.

arm32 uses software to simulate the instruction replaced
by kprobe. some instructions may be simulated by constructing
assembly functions. therefore, before executing instruction
simulation, it is necessary to construct assembly function
execution environment in C language through binding registers.
after kasan is enabled, the register binding relationship will
be destroyed, resulting in instruction simulation errors and
causing kernel panic.

the kprobe emulate instruction function is distributed in three
files: actions-common.c actions-arm.c actions-thumb.c, so disable
KASAN when compiling these files.

for example, use kprobe insert on cap_capable+20 after kasan
enabled, the cap_capable assembly code is as follows:
<cap_capable>:
e92d47f0	push	{r4, r5, r6, r7, r8, r9, sl, lr}
e1a05000	mov	r5, r0
e280006c	add	r0, r0, #108    ; 0x6c
e1a04001	mov	r4, r1
e1a06002	mov	r6, r2
e59fa090	ldr	sl, [pc, #144]  ;
ebfc7bf8	bl	c03aa4b4 <__asan_load4>
e595706c	ldr	r7, [r5, #108]  ; 0x6c
e2859014	add	r9, r5, #20
......
The emulate_ldr assembly code after enabling kasan is as follows:
c06f1384 <emulate_ldr>:
e92d47f0	push	{r4, r5, r6, r7, r8, r9, sl, lr}
e282803c	add	r8, r2, #60     ; 0x3c
e1a05000	mov	r5, r0
e7e37855	ubfx	r7, r5, #16, #4
e1a00008	mov	r0, r8
e1a09001	mov	r9, r1
e1a04002	mov	r4, r2
ebf35462	bl	c03c6530 <__asan_load4>
e357000f	cmp	r7, #15
e7e36655	ubfx	r6, r5, #12, #4
e205a00f	and	sl, r5, #15
0a000001	beq	c06f13bc <emulate_ldr+0x38>
e0840107	add	r0, r4, r7, lsl #2
ebf3545c	bl	c03c6530 <__asan_load4>
e084010a	add	r0, r4, sl, lsl #2
ebf3545a	bl	c03c6530 <__asan_load4>
e2890010	add	r0, r9, #16
ebf35458	bl	c03c6530 <__asan_load4>
e5990010	ldr	r0, [r9, #16]
e12fff30	blx	r0
e356000f	cm	r6, #15
1a000014	bne	c06f1430 <emulate_ldr+0xac>
e1a06000	mov	r6, r0
e2840040	add	r0, r4, #64     ; 0x40
......

when running in emulate_ldr to simulate the ldr instruction, panic
occurred, and the log is as follows:
Unable to handle kernel NULL pointer dereference at virtual address
00000090
pgd = ecb46400
[00000090] *pgd=2e0fa003, *pmd=00000000
Internal error: Oops: 206 [#1] SMP ARM
PC is at cap_capable+0x14/0xb0
LR is at emulate_ldr+0x50/0xc0
psr: 600d0293 sp : ecd63af8  ip : 00000004  fp : c0a7c30c
r10: 00000000  r9 : c30897f4  r8 : ecd63cd4
r7 : 0000000f  r6 : 0000000a  r5 : e59fa090  r4 : ecd63c98
r3 : c06ae294  r2 : 00000000  r1 : b7611300  r0 : bf4ec008
Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 32c5387d  Table: 2d546400  DAC: 55555555
Process bash (pid: 1643, stack limit = 0xecd60190)
(cap_capable) from (kprobe_handler+0x218/0x340)
(kprobe_handler) from (kprobe_trap_handler+0x24/0x48)
(kprobe_trap_handler) from (do_undefinstr+0x13c/0x364)
(do_undefinstr) from (__und_svc_finish+0x0/0x30)
(__und_svc_finish) from (cap_capable+0x18/0xb0)
(cap_capable) from (cap_vm_enough_memory+0x38/0x48)
(cap_vm_enough_memory) from
(security_vm_enough_memory_mm+0x48/0x6c)
(security_vm_enough_memory_mm) from
(copy_process.constprop.5+0x16b4/0x25c8)
(copy_process.constprop.5) from (_do_fork+0xe8/0x55c)
(_do_fork) from (SyS_clone+0x1c/0x24)
(SyS_clone) from (__sys_trace_return+0x0/0x10)
Code: 0050a0e1 6c0080e2 0140a0e1 0260a0e1 (f801f0e7)

Fixes: 35aa1df ("ARM kprobes: instruction single-stepping support")
Fixes: 4210157 ("ARM: 9017/2: Enable KASan for ARM")
Signed-off-by: huangshaobo <huangshaobo6@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Feb 16, 2022
commit 232796d upstream.

When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:

- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;

- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.

This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.

Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.

When this deadlock happens, it produces a trace like the following:

  INFO: task syz-executor:25604 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
  btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
  btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
  btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f86920b2c4d
  RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
  RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
  RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
  R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
  INFO: task syz-executor:25628 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
  __mutex_lock_common kernel/locking/mutex.c:669 [inline]
  __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
  btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
  btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
  btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: stable@vger.kernel.org # 4.19
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request Mar 11, 2022
commit b7d6f44 upstream.

Rolf Eike Beer reported the following bug:

[1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018
[1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4
[1274934.746891] Hardware name: 9000/785/C8000
[1274934.746891]
[1274934.746891]      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
[1274934.746891] PSW: 00001000000001001111111000001110 Not tainted
[1274934.746891] r00-03  000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000
[1274934.746891] r04-07  0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001
[1274934.746891] r08-11  0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001
[1274934.746891] r12-15  0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0
[1274934.746891] r16-19  0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007
[1274934.746891] r20-23  0000000000000006 000000004a368950 0000000000000000 0000000000000001
[1274934.746891] r24-27  0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0
[1274934.746891] r28-31  0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118
[1274934.746891] sr00-03  00000000066e5800 0000000000000000 0000000000000000 00000000066e5800
[1274934.746891] sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
[1274934.746891]
[1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec
[1274934.746891]  IIR: 48780030    ISR: 0000000000000000  IOR: 0000004140000018
[1274934.746891]  CPU:        3   CR30: 00000040e3a9c000 CR31: ffffffffffffffff
[1274934.746891]  ORIG_R28: 0000000040acdd58
[1274934.746891]  IAOQ[0]: sba_unmap_sg+0xb0/0x118
[1274934.746891]  IAOQ[1]: sba_unmap_sg+0xb4/0x118
[1274934.746891]  RP(r2): sba_unmap_sg+0xac/0x118
[1274934.746891] Backtrace:
[1274934.746891]  [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70
[1274934.746891]  [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60
[1274934.746891]  [<00000000407a3488>] mptscsih_io_done+0x150/0xd70
[1274934.746891]  [<0000000040798600>] mpt_interrupt+0x168/0xa68
[1274934.746891]  [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278
[1274934.746891]  [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8
[1274934.746891]  [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0
[1274934.746891]  [<00000000402548e0>] generic_handle_irq+0x50/0x70
[1274934.746891]  [<000000004019a254>] call_on_stack+0x18/0x24
[1274934.746891]
[1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?)

The bug is caused by overrunning the sglist and incorrectly testing
sg_dma_len(sglist) before nents. Normally this doesn't cause a crash,
but in this case sglist crossed a page boundary. This occurs in the
following code:

	while (sg_dma_len(sglist) && nents--) {

The fix is simply to test nents first and move the decrement of nents
into the loop.

Reported-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Mar 15, 2022
commit b7d6f44 upstream.

Rolf Eike Beer reported the following bug:

[1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018
[1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4
[1274934.746891] Hardware name: 9000/785/C8000
[1274934.746891]
[1274934.746891]      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
[1274934.746891] PSW: 00001000000001001111111000001110 Not tainted
[1274934.746891] r00-03  000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000
[1274934.746891] r04-07  0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001
[1274934.746891] r08-11  0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001
[1274934.746891] r12-15  0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0
[1274934.746891] r16-19  0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007
[1274934.746891] r20-23  0000000000000006 000000004a368950 0000000000000000 0000000000000001
[1274934.746891] r24-27  0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0
[1274934.746891] r28-31  0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118
[1274934.746891] sr00-03  00000000066e5800 0000000000000000 0000000000000000 00000000066e5800
[1274934.746891] sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
[1274934.746891]
[1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec
[1274934.746891]  IIR: 48780030    ISR: 0000000000000000  IOR: 0000004140000018
[1274934.746891]  CPU:        3   CR30: 00000040e3a9c000 CR31: ffffffffffffffff
[1274934.746891]  ORIG_R28: 0000000040acdd58
[1274934.746891]  IAOQ[0]: sba_unmap_sg+0xb0/0x118
[1274934.746891]  IAOQ[1]: sba_unmap_sg+0xb4/0x118
[1274934.746891]  RP(r2): sba_unmap_sg+0xac/0x118
[1274934.746891] Backtrace:
[1274934.746891]  [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70
[1274934.746891]  [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60
[1274934.746891]  [<00000000407a3488>] mptscsih_io_done+0x150/0xd70
[1274934.746891]  [<0000000040798600>] mpt_interrupt+0x168/0xa68
[1274934.746891]  [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278
[1274934.746891]  [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8
[1274934.746891]  [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0
[1274934.746891]  [<00000000402548e0>] generic_handle_irq+0x50/0x70
[1274934.746891]  [<000000004019a254>] call_on_stack+0x18/0x24
[1274934.746891]
[1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?)

The bug is caused by overrunning the sglist and incorrectly testing
sg_dma_len(sglist) before nents. Normally this doesn't cause a crash,
but in this case sglist crossed a page boundary. This occurs in the
following code:

	while (sg_dma_len(sglist) && nents--) {

The fix is simply to test nents first and move the decrement of nents
into the loop.

Reported-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian referenced this pull request in gratian/linux Mar 15, 2022
[ Upstream commit 3d6cc98 ]

When cifs_get_root() fails during cifs_smb3_do_mount() we call
deactivate_locked_super() which eventually will call delayed_free() which
will free the context.
In this situation we should not proceed to enter the out: section in
cifs_smb3_do_mount() and free the same resources a second time.

[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0

[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G           OE     5.17.0-rc3+ #4
[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019
[Thu Feb 10 12:59:06 2022] Call Trace:
[Thu Feb 10 12:59:06 2022]  <IRQ>
[Thu Feb 10 12:59:06 2022]  dump_stack_lvl+0x5d/0x78
[Thu Feb 10 12:59:06 2022]  print_address_description.constprop.0+0x24/0x150
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  kasan_report.cold+0x7d/0x117
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  __asan_load8+0x86/0xa0
[Thu Feb 10 12:59:06 2022]  rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  rcu_core+0x547/0xca0
[Thu Feb 10 12:59:06 2022]  ? call_rcu+0x3c0/0x3c0
[Thu Feb 10 12:59:06 2022]  ? __this_cpu_preempt_check+0x13/0x20
[Thu Feb 10 12:59:06 2022]  ? lock_is_held_type+0xea/0x140
[Thu Feb 10 12:59:06 2022]  rcu_core_si+0xe/0x10
[Thu Feb 10 12:59:06 2022]  __do_softirq+0x1d4/0x67b
[Thu Feb 10 12:59:06 2022]  __irq_exit_rcu+0x100/0x150
[Thu Feb 10 12:59:06 2022]  irq_exit_rcu+0xe/0x30
[Thu Feb 10 12:59:06 2022]  sysvec_hyperv_stimer0+0x9d/0xc0
...
[Thu Feb 10 12:59:07 2022] Freed by task 58179:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  kasan_set_track+0x25/0x30
[Thu Feb 10 12:59:07 2022]  kasan_set_free_info+0x24/0x40
[Thu Feb 10 12:59:07 2022]  ____kasan_slab_free+0x137/0x170
[Thu Feb 10 12:59:07 2022]  __kasan_slab_free+0x12/0x20
[Thu Feb 10 12:59:07 2022]  slab_free_freelist_hook+0xb3/0x1d0
[Thu Feb 10 12:59:07 2022]  kfree+0xcd/0x520
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0x149/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

[Thu Feb 10 12:59:07 2022] Last potentially related work creation:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  __kasan_record_aux_stack+0xb6/0xc0
[Thu Feb 10 12:59:07 2022]  kasan_record_aux_stack_noalloc+0xb/0x10
[Thu Feb 10 12:59:07 2022]  call_rcu+0x76/0x3c0
[Thu Feb 10 12:59:07 2022]  cifs_umount+0xce/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  cifs_kill_sb+0xc8/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  deactivate_locked_super+0x5d/0xd0
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0xab9/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Apr 5, 2022
[ Upstream commit 3d6cc98 ]

When cifs_get_root() fails during cifs_smb3_do_mount() we call
deactivate_locked_super() which eventually will call delayed_free() which
will free the context.
In this situation we should not proceed to enter the out: section in
cifs_smb3_do_mount() and free the same resources a second time.

[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0

[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G           OE     5.17.0-rc3+ #4
[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019
[Thu Feb 10 12:59:06 2022] Call Trace:
[Thu Feb 10 12:59:06 2022]  <IRQ>
[Thu Feb 10 12:59:06 2022]  dump_stack_lvl+0x5d/0x78
[Thu Feb 10 12:59:06 2022]  print_address_description.constprop.0+0x24/0x150
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  kasan_report.cold+0x7d/0x117
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  __asan_load8+0x86/0xa0
[Thu Feb 10 12:59:06 2022]  rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  rcu_core+0x547/0xca0
[Thu Feb 10 12:59:06 2022]  ? call_rcu+0x3c0/0x3c0
[Thu Feb 10 12:59:06 2022]  ? __this_cpu_preempt_check+0x13/0x20
[Thu Feb 10 12:59:06 2022]  ? lock_is_held_type+0xea/0x140
[Thu Feb 10 12:59:06 2022]  rcu_core_si+0xe/0x10
[Thu Feb 10 12:59:06 2022]  __do_softirq+0x1d4/0x67b
[Thu Feb 10 12:59:06 2022]  __irq_exit_rcu+0x100/0x150
[Thu Feb 10 12:59:06 2022]  irq_exit_rcu+0xe/0x30
[Thu Feb 10 12:59:06 2022]  sysvec_hyperv_stimer0+0x9d/0xc0
...
[Thu Feb 10 12:59:07 2022] Freed by task 58179:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  kasan_set_track+0x25/0x30
[Thu Feb 10 12:59:07 2022]  kasan_set_free_info+0x24/0x40
[Thu Feb 10 12:59:07 2022]  ____kasan_slab_free+0x137/0x170
[Thu Feb 10 12:59:07 2022]  __kasan_slab_free+0x12/0x20
[Thu Feb 10 12:59:07 2022]  slab_free_freelist_hook+0xb3/0x1d0
[Thu Feb 10 12:59:07 2022]  kfree+0xcd/0x520
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0x149/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

[Thu Feb 10 12:59:07 2022] Last potentially related work creation:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  __kasan_record_aux_stack+0xb6/0xc0
[Thu Feb 10 12:59:07 2022]  kasan_record_aux_stack_noalloc+0xb/0x10
[Thu Feb 10 12:59:07 2022]  call_rcu+0x76/0x3c0
[Thu Feb 10 12:59:07 2022]  cifs_umount+0xce/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  cifs_kill_sb+0xc8/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  deactivate_locked_super+0x5d/0xd0
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0xab9/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux Apr 5, 2022
[ Upstream commit 4cb9a99 ]

I saw the below splatting after the host suspended and resumed.

   WARNING: CPU: 0 PID: 2943 at kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:5531 kvm_resume+0x2c/0x30 [kvm]
   CPU: 0 PID: 2943 Comm: step_after_susp Tainted: G        W IOE     5.17.0-rc3+ #4
   RIP: 0010:kvm_resume+0x2c/0x30 [kvm]
   Call Trace:
    <TASK>
    syscore_resume+0x90/0x340
    suspend_devices_and_enter+0xaee/0xe90
    pm_suspend.cold+0x36b/0x3c2
    state_store+0x82/0xf0
    kernfs_fop_write_iter+0x1b6/0x260
    new_sync_write+0x258/0x370
    vfs_write+0x33f/0x510
    ksys_write+0xc9/0x160
    do_syscall_64+0x3b/0xc0
    entry_SYSCALL_64_after_hwframe+0x44/0xae

lockdep_is_held() can return -1 when lockdep is disabled which triggers
this warning. Let's use lockdep_assert_not_held() which can detect
incorrect calls while holding a lock and it also avoids false negatives
when lockdep is disabled.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1644920142-81249-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request May 10, 2022
[ Upstream commit fe2640b ]

In remove_phb_dynamic() we use &phb->io_resource, after we've called
device_unregister(&host_bridge->dev). But the unregister may have freed
phb, because pcibios_free_controller_deferred() is the release function
for the host_bridge.

If there are no outstanding references when we call device_unregister()
then phb will be freed out from under us.

This has gone mainly unnoticed, but with slub_debug and page_poison
enabled it can lead to a crash:

  PID: 7574   TASK: c0000000d492cb80  CPU: 13  COMMAND: "drmgr"
   #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc
   #1 [c0000000e4f075d0] oops_end at c000000000029608
   #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4
   #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8
   #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30
   Data SLB Access [380] exception frame:
   R0:  c000000000167250    R1:  c0000000e4f07a00    R2:  c000000002a46100
   R3:  c000000002b39ce8    R4:  00000000000000c0    R5:  00000000000000a9
   R6:  3894674d000000c0    R7:  0000000000000000    R8:  00000000000000ff
   R9:  0000000000000100    R10: 6b6b6b6b6b6b6b6b    R11: 0000000000008000
   R12: c00000000023da80    R13: c0000009ffd38b00    R14: 0000000000000000
   R15: 000000011c87f0f0    R16: 0000000000000006    R17: 0000000000000003
   R18: 0000000000000002    R19: 0000000000000004    R20: 0000000000000005
   R21: 000000011c87ede8    R22: 000000011c87c5a8    R23: 000000011c87d3a0
   R24: 0000000000000000    R25: 0000000000000001    R26: c0000000e4f07cc8
   R27: c00000004d1cc400    R28: c0080000031d00e8    R29: c00000004d23d800
   R30: c00000004d1d2400    R31: c00000004d1d2540
   NIP: c000000000167258    MSR: 8000000000009033    OR3: c000000000e9f474
   CTR: 0000000000000000    LR:  c000000000167250    XER: 0000000020040003
   CCR: 0000000024088420    MQ:  0000000000000000    DAR: 6b6b6b6b6b6b6ba3
   DSISR: c0000000e4f07920     Syscall Result: fffffffffffffff2
   [NIP  : release_resource+56]
   [LR   : release_resource+48]
   #5 [c0000000e4f07a00] release_resource at c000000000167258  (unreliable)
   #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648
   #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io]
   #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io]
   #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c
  #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504
  #11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868
  #12 [c0000000e4f07c70] new_sync_write at c00000000054339c
  #13 [c0000000e4f07d10] vfs_write at c000000000546624
  #14 [c0000000e4f07d60] ksys_write at c0000000005469f4
  #15 [c0000000e4f07db0] system_call_exception at c000000000030840
  #16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168

To avoid it, we can take a reference to the host_bridge->dev until we're
done using phb. Then when we drop the reference the phb will be freed.

Fixes: 2dd9c11 ("powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb)")
Reported-by: David Dai <zdai@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Link: https://lore.kernel.org/r/20220318034219.1188008-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request May 10, 2022
[ Upstream commit 841aee4 ]

Put NVMe/TCP sockets in their own class to avoid some lockdep warnings.
Sockets created by nvme-tcp are not exposed to user-space, and will not
trigger certain code paths that the general socket API exposes.

Lockdep complains about a circular dependency between the socket and
filesystem locks, because setsockopt can trigger a page fault with a
socket lock held, but nvme-tcp sends requests on the socket while file
system locks are held.

  ======================================================
  WARNING: possible circular locking dependency detected
  5.15.0-rc3 #1 Not tainted
  ------------------------------------------------------
  fio/1496 is trying to acquire lock:
  (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendpage+0x23/0x80

  but task is already holding lock:
  (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]

  which lock already depends on the new lock.

  other info that might help us debug this:

  chain exists of:
   sk_lock-AF_INET --> sb_internal --> &xfs_dir_ilock_class/5

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xfs_dir_ilock_class/5);
                                lock(sb_internal);
                                lock(&xfs_dir_ilock_class/5);
   lock(sk_lock-AF_INET);

  *** DEADLOCK ***

  6 locks held by fio/1496:
   #0: (sb_writers#13){.+.+}-{0:0}, at: path_openat+0x9fc/0xa20
   #1: (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: path_openat+0x296/0xa20
   #2: (sb_internal){.+.+}-{0:0}, at: xfs_trans_alloc_icreate+0x41/0xd0 [xfs]
   #3: (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
   #4: (hctx->srcu){....}-{0:0}, at: hctx_lock+0x51/0xd0
   #5: (&queue->send_mutex){+.+.}-{3:3}, at: nvme_tcp_queue_rq+0x33e/0x380 [nvme_tcp]

This annotation lets lockdep analyze nvme-tcp controlled sockets
independently of what the user-space sockets API does.

Link: https://lore.kernel.org/linux-nvme/CAHj4cs9MDYLJ+q+2_GXUK9HxFizv2pxUryUR0toX974M040z7g@mail.gmail.com/

Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request May 10, 2022
commit a80ced6 upstream.

As guest_irq is coming from KVM_IRQFD API call, it may trigger
crash in svm_update_pi_irte() due to out-of-bounds:

crash> bt
PID: 22218  TASK: ffff951a6ad74980  CPU: 73  COMMAND: "vcpu8"
 #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397
 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d
 #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d
 #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d
 #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9
 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51
 #6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace
    [exception RIP: svm_update_pi_irte+227]
    RIP: ffffffffc0761b53  RSP: ffffb1ba6707fd08  RFLAGS: 00010086
    RAX: ffffb1ba6707fd78  RBX: ffffb1ba66d91000  RCX: 0000000000000001
    RDX: 00003c803f63f1c0  RSI: 000000000000019a  RDI: ffffb1ba66db2ab8
    RBP: 000000000000019a   R8: 0000000000000040   R9: ffff94ca41b82200
    R10: ffffffffffffffcf  R11: 0000000000000001  R12: 0000000000000001
    R13: 0000000000000001  R14: ffffffffffffffcf  R15: 000000000000005f
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm]
 #8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm]
 #9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm]
    RIP: 00007f143c36488b  RSP: 00007f143a4e04b8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 00007f05780041d0  RCX: 00007f143c36488b
    RDX: 00007f05780041d0  RSI: 000000004008ae6a  RDI: 0000000000000020
    RBP: 00000000000004e8   R8: 0000000000000008   R9: 00007f05780041e0
    R10: 00007f0578004560  R11: 0000000000000246  R12: 00000000000004e0
    R13: 000000000000001a  R14: 00007f1424001c60  R15: 00007f0578003bc0
    ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

Vmx have been fix this in commit 3a8b067 (KVM: VMX: Do not BUG() on
out-of-bounds guest IRQ), so we can just copy source from that to fix
this.

Co-developed-by: Yi Liu <liu.yi24@zte.com.cn>
Signed-off-by: Yi Liu <liu.yi24@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Message-Id: <20220309113025.44469-1-wang.yi59@zte.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gratian pushed a commit that referenced this pull request May 10, 2022
[ Upstream commit 447c799 ]

Noticed the below warning while running a pytorch workload on vega10
GPUs. Change to trylock to avoid conflicts with already held reservation
locks.

[  +0.000003] WARNING: possible recursive locking detected
[  +0.000003] 5.13.0-kfd-rajneesh #1030 Not tainted
[  +0.000004] --------------------------------------------
[  +0.000002] python/4822 is trying to acquire lock:
[  +0.000004] ffff932cd9a259f8 (reservation_ww_class_mutex){+.+.}-{3:3},
at: amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000203]
              but task is already holding lock:
[  +0.000003] ffff932cbb7181f8 (reservation_ww_class_mutex){+.+.}-{3:3},
at: ttm_eu_reserve_buffers+0x270/0x470 [ttm]
[  +0.000017]
              other info that might help us debug this:
[  +0.000002]  Possible unsafe locking scenario:

[  +0.000003]        CPU0
[  +0.000002]        ----
[  +0.000002]   lock(reservation_ww_class_mutex);
[  +0.000004]   lock(reservation_ww_class_mutex);
[  +0.000003]
               *** DEADLOCK ***

[  +0.000002]  May be due to missing lock nesting notation

[  +0.000003] 7 locks held by python/4822:
[  +0.000003]  #0: ffff932c4ac028d0 (&process->mutex){+.+.}-{3:3}, at:
kfd_ioctl_map_memory_to_gpu+0x10b/0x320 [amdgpu]
[  +0.000232]  #1: ffff932c55e830a8 (&info->lock#2){+.+.}-{3:3}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x64/0xf60 [amdgpu]
[  +0.000241]  #2: ffff932cc45b5e68 (&(*mem)->lock){+.+.}-{3:3}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0xdf/0xf60 [amdgpu]
[  +0.000236]  #3: ffffb2b35606fd28
(reservation_ww_class_acquire){+.+.}-{0:0}, at:
amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x232/0xf60 [amdgpu]
[  +0.000235]  #4: ffff932cbb7181f8
(reservation_ww_class_mutex){+.+.}-{3:3}, at:
ttm_eu_reserve_buffers+0x270/0x470 [ttm]
[  +0.000015]  #5: ffffffffc045f700 (*(sspp++)){....}-{0:0}, at:
drm_dev_enter+0x5/0xa0 [drm]
[  +0.000038]  #6: ffff932c52da7078 (&vm->eviction_lock){+.+.}-{3:3},
at: amdgpu_vm_bo_update_mapping+0xd5/0x4f0 [amdgpu]
[  +0.000195]
              stack backtrace:
[  +0.000003] CPU: 11 PID: 4822 Comm: python Not tainted
5.13.0-kfd-rajneesh #1030
[  +0.000005] Hardware name: GIGABYTE MZ01-CE0-00/MZ01-CE0-00, BIOS F02
08/29/2018
[  +0.000003] Call Trace:
[  +0.000003]  dump_stack+0x6d/0x89
[  +0.000010]  __lock_acquire+0xb93/0x1a90
[  +0.000009]  lock_acquire+0x25d/0x2d0
[  +0.000005]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000184]  ? lock_is_held_type+0xa2/0x110
[  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000184]  __ww_mutex_lock.constprop.17+0xca/0x1060
[  +0.000007]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000183]  ? lock_release+0x13f/0x270
[  +0.000005]  ? lock_is_held_type+0xa2/0x110
[  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000183]  amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
[  +0.000185]  ttm_bo_release+0x4c6/0x580 [ttm]
[  +0.000010]  amdgpu_bo_unref+0x1a/0x30 [amdgpu]
[  +0.000183]  amdgpu_vm_free_table+0x76/0xa0 [amdgpu]
[  +0.000189]  amdgpu_vm_free_pts+0xb8/0xf0 [amdgpu]
[  +0.000189]  amdgpu_vm_update_ptes+0x411/0x770 [amdgpu]
[  +0.000191]  amdgpu_vm_bo_update_mapping+0x324/0x4f0 [amdgpu]
[  +0.000191]  amdgpu_vm_bo_update+0x251/0x610 [amdgpu]
[  +0.000191]  update_gpuvm_pte+0xcc/0x290 [amdgpu]
[  +0.000229]  ? amdgpu_vm_bo_map+0xd7/0x130 [amdgpu]
[  +0.000190]  amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x912/0xf60
[amdgpu]
[  +0.000234]  kfd_ioctl_map_memory_to_gpu+0x182/0x320 [amdgpu]
[  +0.000218]  kfd_ioctl+0x2b9/0x600 [amdgpu]
[  +0.000216]  ? kfd_ioctl_unmap_memory_from_gpu+0x270/0x270 [amdgpu]
[  +0.000216]  ? lock_release+0x13f/0x270
[  +0.000006]  ? __fget_files+0x107/0x1e0
[  +0.000007]  __x64_sys_ioctl+0x8b/0xd0
[  +0.000007]  do_syscall_64+0x36/0x70
[  +0.000004]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  +0.000007] RIP: 0033:0x7fbff90a7317
[  +0.000004] Code: b3 66 90 48 8b 05 71 4b 2d 00 64 c7 00 26 00 00 00
48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 4b 2d 00 f7 d8 64 89 01 48
[  +0.000005] RSP: 002b:00007fbe301fe648 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[  +0.000006] RAX: ffffffffffffffda RBX: 00007fbcc402d820 RCX:
00007fbff90a7317
[  +0.000003] RDX: 00007fbe301fe690 RSI: 00000000c0184b18 RDI:
0000000000000004
[  +0.000003] RBP: 00007fbe301fe690 R08: 0000000000000000 R09:
00007fbcc402d880
[  +0.000003] R10: 0000000002001000 R11: 0000000000000246 R12:
00000000c0184b18
[  +0.000003] R13: 0000000000000004 R14: 00007fbf689593a0 R15:
00007fbcc402d820

Cc: Christian König <christian.koenig@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request May 10, 2022
[ Upstream commit 059a47f ]

After rx/tx ring buffer size is changed, kernel panic occurs when
it acts XDP_TX or XDP_REDIRECT.

When tx/rx ring buffer size is changed(ethtool -G), sfc driver
reallocates and reinitializes rx and tx queues and their buffer
(tx_queue->buffer).
But it misses reinitializing xdp queues(efx->xdp_tx_queues).
So, while it is acting XDP_TX or XDP_REDIRECT, it uses the uninitialized
tx_queue->buffer.

A new function efx_set_xdp_channels() is separated from efx_set_channels()
to handle only xdp queues.

Splat looks like:
   BUG: kernel NULL pointer dereference, address: 000000000000002a
   #PF: supervisor write access in kernel mode
   #PF: error_code(0x0002) - not-present page
   PGD 0 P4D 0
   Oops: 0002 [#4] PREEMPT SMP NOPTI
   RIP: 0010:efx_tx_map_chunk+0x54/0x90 [sfc]
   CPU: 2 PID: 0 Comm: swapper/2 Tainted: G      D           5.17.0+ #55 e8beeee8289528f11357029357cf
   Code: 48 8b 8d a8 01 00 00 48 8d 14 52 4c 8d 2c d0 44 89 e0 48 85 c9 74 0e 44 89 e2 4c 89 f6 48 80
   RSP: 0018:ffff92f121e45c60 EFLAGS: 00010297
   RIP: 0010:efx_tx_map_chunk+0x54/0x90 [sfc]
   RAX: 0000000000000040 RBX: ffff92ea506895c0 RCX: ffffffffc0330870
   RDX: 0000000000000001 RSI: 00000001139b10ce RDI: ffff92ea506895c0
   RBP: ffffffffc0358a80 R08: 00000001139b110d R09: 0000000000000000
   R10: 0000000000000001 R11: ffff92ea414c0088 R12: 0000000000000040
   R13: 0000000000000018 R14: 00000001139b10ce R15: ffff92ea506895c0
   FS:  0000000000000000(0000) GS:ffff92f121ec0000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   Code: 48 8b 8d a8 01 00 00 48 8d 14 52 4c 8d 2c d0 44 89 e0 48 85 c9 74 0e 44 89 e2 4c 89 f6 48 80
   CR2: 000000000000002a CR3: 00000003e6810004 CR4: 00000000007706e0
   RSP: 0018:ffff92f121e85c60 EFLAGS: 00010297
   PKRU: 55555554
   RAX: 0000000000000040 RBX: ffff92ea50689700 RCX: ffffffffc0330870
   RDX: 0000000000000001 RSI: 00000001145a90ce RDI: ffff92ea50689700
   RBP: ffffffffc0358a80 R08: 00000001145a910d R09: 0000000000000000
   R10: 0000000000000001 R11: ffff92ea414c0088 R12: 0000000000000040
   R13: 0000000000000018 R14: 00000001145a90ce R15: ffff92ea50689700
   FS:  0000000000000000(0000) GS:ffff92f121e80000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 000000000000002a CR3: 00000003e6810005 CR4: 00000000007706e0
   PKRU: 55555554
   Call Trace:
    <IRQ>
    efx_xdp_tx_buffers+0x12b/0x3d0 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]
    __efx_rx_packet+0x5c3/0x930 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]
    efx_rx_packet+0x28c/0x2e0 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]
    efx_ef10_ev_process+0x5f8/0xf40 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]
    ? enqueue_task_fair+0x95/0x550
    efx_poll+0xc4/0x360 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]

Fixes: 3990a8f ("sfc: allocate channels for XDP tx queues")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian pushed a commit that referenced this pull request May 10, 2022
[ Upstream commit 8b2c181 ]

There is possible circular locking dependency detected on event_mutex
(see below logs). This is due to set fail safe mode is done at
dp_panel_read_sink_caps() within event_mutex scope. To break this
possible circular locking, this patch move setting fail safe mode
out of event_mutex scope.

[   23.958078] ======================================================
[   23.964430] WARNING: possible circular locking dependency detected
[   23.970777] 5.17.0-rc2-lockdep-00088-g05241de1f69e #148 Not tainted
[   23.977219] ------------------------------------------------------
[   23.983570] DrmThread/1574 is trying to acquire lock:
[   23.988763] ffffff808423aab0 (&dp->event_mutex){+.+.}-{3:3}, at: msm_dp_displ                                                                             ay_enable+0x58/0x164
[   23.997895]
[   23.997895] but task is already holding lock:
[   24.003895] ffffff808420b280 (&kms->commit_lock[i]/1){+.+.}-{3:3}, at: lock_c                                                                             rtcs+0x80/0x8c
[   24.012495]
[   24.012495] which lock already depends on the new lock.
[   24.012495]
[   24.020886]
[   24.020886] the existing dependency chain (in reverse order) is:
[   24.028570]
[   24.028570] -> #5 (&kms->commit_lock[i]/1){+.+.}-{3:3}:
[   24.035472]        __mutex_lock+0xc8/0x384
[   24.039695]        mutex_lock_nested+0x54/0x74
[   24.044272]        lock_crtcs+0x80/0x8c
[   24.048222]        msm_atomic_commit_tail+0x1e8/0x3d0
[   24.053413]        commit_tail+0x7c/0xfc
[   24.057452]        drm_atomic_helper_commit+0x158/0x15c
[   24.062826]        drm_atomic_commit+0x60/0x74
[   24.067403]        drm_mode_atomic_ioctl+0x6b0/0x908
[   24.072508]        drm_ioctl_kernel+0xe8/0x168
[   24.077086]        drm_ioctl+0x320/0x370
[   24.081123]        drm_compat_ioctl+0x40/0xdc
[   24.085602]        __arm64_compat_sys_ioctl+0xe0/0x150
[   24.090895]        invoke_syscall+0x80/0x114
[   24.095294]        el0_svc_common.constprop.3+0xc4/0xf8
[   24.100668]        do_el0_svc_compat+0x2c/0x54
[   24.105242]        el0_svc_compat+0x4c/0xe4
[   24.109548]        el0t_32_sync_handler+0xc4/0xf4
[   24.114381]        el0t_32_sync+0x178
[   24.118688]
[   24.118688] -> #4 (&kms->commit_lock[i]){+.+.}-{3:3}:
[   24.125408]        __mutex_lock+0xc8/0x384
[   24.129628]        mutex_lock_nested+0x54/0x74
[   24.134204]        lock_crtcs+0x80/0x8c
[   24.138155]        msm_atomic_commit_tail+0x1e8/0x3d0
[   24.143345]        commit_tail+0x7c/0xfc
[   24.147382]        drm_atomic_helper_commit+0x158/0x15c
[   24.152755]        drm_atomic_commit+0x60/0x74
[   24.157323]        drm_atomic_helper_set_config+0x68/0x90
[   24.162869]        drm_mode_setcrtc+0x394/0x648
[   24.167535]        drm_ioctl_kernel+0xe8/0x168
[   24.172102]        drm_ioctl+0x320/0x370
[   24.176135]        drm_compat_ioctl+0x40/0xdc
[   24.180621]        __arm64_compat_sys_ioctl+0xe0/0x150
[   24.185904]        invoke_syscall+0x80/0x114
[   24.190302]        el0_svc_common.constprop.3+0xc4/0xf8
[   24.195673]        do_el0_svc_compat+0x2c/0x54
[   24.200241]        el0_svc_compat+0x4c/0xe4
[   24.204544]        el0t_32_sync_handler+0xc4/0xf4
[   24.209378]        el0t_32_sync+0x174/0x178
[   24.213680] -> #3 (crtc_ww_class_mutex){+.+.}-{3:3}:
[   24.220308]        __ww_mutex_lock.constprop.20+0xe8/0x878
[   24.225951]        ww_mutex_lock+0x60/0xd0
[   24.230166]        modeset_lock+0x190/0x19c
[   24.234467]        drm_modeset_lock+0x34/0x54
[   24.238953]        drmm_mode_config_init+0x550/0x764
[   24.244065]        msm_drm_bind+0x170/0x59c
[   24.248374]        try_to_bring_up_master+0x244/0x294
[   24.253572]        __component_add+0xf4/0x14c
[   24.258057]        component_add+0x2c/0x38
[   24.262273]        dsi_dev_attach+0x2c/0x38
[   24.266575]        dsi_host_attach+0xc4/0x120
[   24.271060]        mipi_dsi_attach+0x34/0x48
[   24.275456]        devm_mipi_dsi_attach+0x28/0x68
[   24.280298]        ti_sn_bridge_probe+0x2b4/0x2dc
[   24.285137]        auxiliary_bus_probe+0x78/0x90
[   24.289893]        really_probe+0x1e4/0x3d8
[   24.294194]        __driver_probe_device+0x14c/0x164
[   24.299298]        driver_probe_device+0x54/0xf8
[   24.304043]        __device_attach_driver+0xb4/0x118
[   24.309145]        bus_for_each_drv+0xb0/0xd4
[   24.313628]        __device_attach+0xcc/0x158
[   24.318112]        device_initial_probe+0x24/0x30
[   24.322954]        bus_probe_device+0x38/0x9c
[   24.327439]        deferred_probe_work_func+0xd4/0xf0
[   24.332628]        process_one_work+0x2f0/0x498
[   24.337289]        process_scheduled_works+0x44/0x48
[   24.342391]        worker_thread+0x1e4/0x26c
[   24.346788]        kthread+0xe4/0xf4
[   24.350470]        ret_from_fork+0x10/0x20
[   24.354683]
[   24.354683]
[   24.354683] -> #2 (crtc_ww_class_acquire){+.+.}-{0:0}:
[   24.361489]        drm_modeset_acquire_init+0xe4/0x138
[   24.366777]        drm_helper_probe_detect_ctx+0x44/0x114
[   24.372327]        check_connector_changed+0xbc/0x198
[   24.377517]        drm_helper_hpd_irq_event+0xcc/0x11c
[   24.382804]        dsi_hpd_worker+0x24/0x30
[   24.387104]        process_one_work+0x2f0/0x498
[   24.391762]        worker_thread+0x1d0/0x26c
[   24.396158]        kthread+0xe4/0xf4
[   24.399840]        ret_from_fork+0x10/0x20
[   24.404053]
[   24.404053] -> #1 (&dev->mode_config.mutex){+.+.}-{3:3}:
[   24.411032]        __mutex_lock+0xc8/0x384
[   24.415247]        mutex_lock_nested+0x54/0x74
[   24.419819]        dp_panel_read_sink_caps+0x23c/0x26c
[   24.425108]        dp_display_process_hpd_high+0x34/0xd4
[   24.430570]        dp_display_usbpd_configure_cb+0x30/0x3c
[   24.436205]        hpd_event_thread+0x2ac/0x550
[   24.440864]        kthread+0xe4/0xf4
[   24.444544]        ret_from_fork+0x10/0x20
[   24.448757]
[   24.448757] -> #0 (&dp->event_mutex){+.+.}-{3:3}:
[   24.455116]        __lock_acquire+0xe2c/0x10d8
[   24.459690]        lock_acquire+0x1ac/0x2d0
[   24.463988]        __mutex_lock+0xc8/0x384
[   24.468201]        mutex_lock_nested+0x54/0x74
[   24.472773]        msm_dp_display_enable+0x58/0x164
[   24.477789]        dp_bridge_enable+0x24/0x30
[   24.482273]        drm_atomic_bridge_chain_enable+0x78/0x9c
[   24.488006]        drm_atomic_helper_commit_modeset_enables+0x1bc/0x244
[   24.494801]        msm_atomic_commit_tail+0x248/0x3d0
[   24.499992]        commit_tail+0x7c/0xfc
[   24.504031]        drm_atomic_helper_commit+0x158/0x15c
[   24.509404]        drm_atomic_commit+0x60/0x74
[   24.513976]        drm_mode_atomic_ioctl+0x6b0/0x908
[   24.519079]        drm_ioctl_kernel+0xe8/0x168
[   24.523650]        drm_ioctl+0x320/0x370
[   24.527689]        drm_compat_ioctl+0x40/0xdc
[   24.532175]        __arm64_compat_sys_ioctl+0xe0/0x150
[   24.537463]        invoke_syscall+0x80/0x114
[   24.541861]        el0_svc_common.constprop.3+0xc4/0xf8
[   24.547235]        do_el0_svc_compat+0x2c/0x54
[   24.551806]        el0_svc_compat+0x4c/0xe4
[   24.556106]        el0t_32_sync_handler+0xc4/0xf4
[   24.560948]        el0t_32_sync+0x174/0x178

Changes in v2:
-- add circular lockiing trace

Fixes: d4aca42 ("drm/msm/dp:  always add fail-safe mode into connector mode list")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/481396/
Link: https://lore.kernel.org/r/1649451894-554-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux May 19, 2022
[ Upstream commit 841aee4 ]

Put NVMe/TCP sockets in their own class to avoid some lockdep warnings.
Sockets created by nvme-tcp are not exposed to user-space, and will not
trigger certain code paths that the general socket API exposes.

Lockdep complains about a circular dependency between the socket and
filesystem locks, because setsockopt can trigger a page fault with a
socket lock held, but nvme-tcp sends requests on the socket while file
system locks are held.

  ======================================================
  WARNING: possible circular locking dependency detected
  5.15.0-rc3 #1 Not tainted
  ------------------------------------------------------
  fio/1496 is trying to acquire lock:
  (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendpage+0x23/0x80

  but task is already holding lock:
  (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]

  which lock already depends on the new lock.

  other info that might help us debug this:

  chain exists of:
   sk_lock-AF_INET --> sb_internal --> &xfs_dir_ilock_class/5

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xfs_dir_ilock_class/5);
                                lock(sb_internal);
                                lock(&xfs_dir_ilock_class/5);
   lock(sk_lock-AF_INET);

  *** DEADLOCK ***

  6 locks held by fio/1496:
   #0: (sb_writers#13){.+.+}-{0:0}, at: path_openat+0x9fc/0xa20
   #1: (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: path_openat+0x296/0xa20
   #2: (sb_internal){.+.+}-{0:0}, at: xfs_trans_alloc_icreate+0x41/0xd0 [xfs]
   #3: (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
   #4: (hctx->srcu){....}-{0:0}, at: hctx_lock+0x51/0xd0
   #5: (&queue->send_mutex){+.+.}-{3:3}, at: nvme_tcp_queue_rq+0x33e/0x380 [nvme_tcp]

This annotation lets lockdep analyze nvme-tcp controlled sockets
independently of what the user-space sockets API does.

Link: https://lore.kernel.org/linux-nvme/CAHj4cs9MDYLJ+q+2_GXUK9HxFizv2pxUryUR0toX974M040z7g@mail.gmail.com/

Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gratian referenced this pull request in gratian/linux May 19, 2022
commit a80ced6 upstream.

As guest_irq is coming from KVM_IRQFD API call, it may trigger
crash in svm_update_pi_irte() due to out-of-bounds:

crash> bt
PID: 22218  TASK: ffff951a6ad74980  CPU: 73  COMMAND: "vcpu8"
 #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397
 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d
 #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d
 #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d
 #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9
 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51
 ni#6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace
    [exception RIP: svm_update_pi_irte+227]
    RIP: ffffffffc0761b53  RSP: ffffb1ba6707fd08  RFLAGS: 00010086
    RAX: ffffb1ba6707fd78  RBX: ffffb1ba66d91000  RCX: 0000000000000001
    RDX: 00003c803f63f1c0  RSI: 000000000000019a  RDI: ffffb1ba66db2ab8
    RBP: 000000000000019a   R8: 0000000000000040   R9: ffff94ca41b82200
    R10: ffffffffffffffcf  R11: 0000000000000001  R12: 0000000000000001
    R13: 0000000000000001  R14: ffffffffffffffcf  R15: 000000000000005f
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 ni#7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm]
 ni#8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm]
 ni#9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm]
    RIP: 00007f143c36488b  RSP: 00007f143a4e04b8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 00007f05780041d0  RCX: 00007f143c36488b
    RDX: 00007f05780041d0  RSI: 000000004008ae6a  RDI: 0000000000000020
    RBP: 00000000000004e8   R8: 0000000000000008   R9: 00007f05780041e0
    R10: 00007f0578004560  R11: 0000000000000246  R12: 00000000000004e0
    R13: 000000000000001a  R14: 00007f1424001c60  R15: 00007f0578003bc0
    ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

Vmx have been fix this in commit 3a8b067 (KVM: VMX: Do not BUG() on
out-of-bounds guest IRQ), so we can just copy source from that to fix
this.

Co-developed-by: Yi Liu <liu.yi24@zte.com.cn>
Signed-off-by: Yi Liu <liu.yi24@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Message-Id: <20220309113025.44469-1-wang.yi59@zte.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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3 participants