On 7/3/18 6:04 PM, Rafael Tinoco wrote:
BUG: https://bugs.linaro.org/show_bug.cgi?id=3731
During Linaro's Kernel Functional tests, we have observed the
following situation:
[ 52.651490] DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)1UL))
[ 52.651506] WARNING: CPU: 2 PID: 1457 at
./kernel/locking/rwsem.c:217 up_read_non_owner+0x5d/0x70
[ 52.674398] Modules linked in: x86_pkg_temp_thermal fuse
[ 52.679719] CPU: 2 PID: 1457 Comm: kworker/2:2 Not tainted 4.16.0 #1
[ 52.687448] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[ 52.694922] Workqueue: nfsiod rpc_async_release
[ 52.699454] RIP: 0010:up_read_non_owner+0x5d/0x70
[ 52.704157] RSP: 0018:ffff9cbf81a23dd0 EFLAGS: 00010282
[ 52.709376] RAX: 0000000000000000 RBX: ffff8dc1983c76c0 RCX: 0000000000000000
[ 52.716500] RDX: ffffffffbd2d26c9 RSI: 0000000000000001 RDI: ffffffffbd2d2889
[ 52.723652] RBP: ffff9cbf81a23dd8 R08: 0000000000000000 R09: 0000000000000000
[ 52.730782] R10: ffff9cbf81a23dd0 R11: 0000000000000000 R12: ffff8dc19abf8600
[ 52.737906] R13: ffff8dc19b6c0000 R14: 0000000000000000 R15: ffff8dc19bacad80
[ 52.745029] FS: 0000000000000000(0000) GS:ffff8dc1afd00000(0000)
knlGS:0000000000000000
[ 52.753108] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 52.758845] CR2: 00007f33794665d8 CR3: 000000016c41e006 CR4: 00000000003606e0
[ 52.765968] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 52.773091] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 52.780215] Call Trace:
[ 52.782695] nfs_async_unlink_release+0x32/0x80
[ 52.787220] rpc_free_task+0x30/0x50
[ 52.790789] rpc_async_release+0x12/0x20
[ 52.794707] process_one_work+0x25e/0x660
[ 52.798713] worker_thread+0x4b/0x410
[ 52.802377] kthread+0x10d/0x140
[ 52.805600] ? rescuer_thread+0x3a0/0x3a0
[ 52.809652] ? kthread_create_worker_on_cpu+0x70/0x70
[ 52.814702] ? do_syscall_64+0x69/0x1b0
[ 52.818540] ret_from_fork+0x3a/0x50
Full explanation: https://bugs.linaro.org/show_bug.cgi?id=3731#c15
Appears that:
commit 925b9cd1b89a94b7124d128c80dfc48f78a63098
Author: Waiman Long <long...@redhat.com>
Date: Thu Sep 6 17:18:34 2018
locking/rwsem: Make owner store task pointer of last owning reader
seem to have fixed this warning:
DEBUG_RWSEMS_WARN_ON() started differentiating unknown owners for
semaphores, like in this case, when RPC function forces the release the
dentry's semaphore to avoid issues with NFS filesystem logic (nfs_rmdir,
the real user for the semaphore in question).
Thanks Waiman!
-
Rafael D. Tinoco
Linaro Kernel Validation
