| Message ID | 1436280313-21451-2-git-send-email-haggaie@mellanox.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index ad45469f7582..a700cdb13f3d 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -1354,10 +1354,10 @@ static void ucma_lock_files(struct ucma_file *file1, struct ucma_file *file2) /* Acquire mutex's based on pointer comparison to prevent deadlock. */ if (file1 < file2) { mutex_lock(&file1->mut); - mutex_lock(&file2->mut); + mutex_lock_nested(&file2->mut, SINGLE_DEPTH_NESTING); } else { mutex_lock(&file2->mut); - mutex_lock(&file1->mut); + mutex_lock_nested(&file1->mut, SINGLE_DEPTH_NESTING); } }
The ucma_lock_files() locks the mut mutex on two files, e.g. for migrating an ID. Use mutex_lock_nested() to prevent the warning below. ============================================= [ INFO: possible recursive locking detected ] 4.1.0-rc6-hmm+ #40 Tainted: G O --------------------------------------------- pingpong_rpc_se/10260 is trying to acquire lock: (&file->mut){+.+.+.}, at: [<ffffffffa047ac55>] ucma_migrate_id+0xc5/0x248 [rdma_ucm] but task is already holding lock: (&file->mut){+.+.+.}, at: [<ffffffffa047ac4b>] ucma_migrate_id+0xbb/0x248 [rdma_ucm] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&file->mut); lock(&file->mut); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by pingpong_rpc_se/10260: #0: (&file->mut){+.+.+.}, at: [<ffffffffa047ac4b>] ucma_migrate_id+0xbb/0x248 [rdma_ucm] stack backtrace: CPU: 0 PID: 10260 Comm: pingpong_rpc_se Tainted: G O 4.1.0-rc6-hmm+ #40 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 ffff8801f85b63d0 ffff880195677b58 ffffffff81668f49 0000000000000001 ffffffff825cbbe0 ffff880195677c38 ffffffff810bb991 ffff880100000000 ffff880100000000 ffff880100000001 ffff8801f85b7010 ffffffff8121bee9 Call Trace: [<ffffffff81668f49>] dump_stack+0x4f/0x6e [<ffffffff810bb991>] __lock_acquire+0x741/0x1820 [<ffffffff8121bee9>] ? dput+0x29/0x320 [<ffffffff810bcb38>] lock_acquire+0xc8/0x240 [<ffffffffa047ac55>] ? ucma_migrate_id+0xc5/0x248 [rdma_ucm] [<ffffffff8166b901>] ? mutex_lock_nested+0x291/0x3e0 [<ffffffff8166b6d5>] mutex_lock_nested+0x65/0x3e0 [<ffffffffa047ac55>] ? ucma_migrate_id+0xc5/0x248 [rdma_ucm] [<ffffffff810baeed>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff8166b66e>] ? mutex_unlock+0xe/0x10 [<ffffffffa047ac55>] ucma_migrate_id+0xc5/0x248 [rdma_ucm] [<ffffffffa0478474>] ucma_write+0xa4/0xb0 [rdma_ucm] [<ffffffff81200674>] __vfs_write+0x34/0x100 [<ffffffff8112427c>] ? __audit_syscall_entry+0xac/0x110 [<ffffffff810ec055>] ? current_kernel_time+0xc5/0xe0 [<ffffffff812aa4d3>] ? security_file_permission+0x23/0x90 [<ffffffff8120088d>] ? rw_verify_area+0x5d/0xe0 [<ffffffff812009bb>] vfs_write+0xab/0x120 [<ffffffff81201519>] SyS_write+0x59/0xd0 [<ffffffff8112427c>] ? __audit_syscall_entry+0xac/0x110 [<ffffffff8166ffee>] system_call_fastpath+0x12/0x76 Signed-off-by: Haggai Eran <haggaie@mellanox.com> --- drivers/infiniband/core/ucma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)