]> git.baikalelectronics.ru Git - kernel.git/commit
IB/hfi1,IB/qib: Fix qp_stats sleep with rcu read lock held
authorMike Marciniszyn <mike.marciniszyn@intel.com>
Fri, 12 Aug 2016 15:17:37 +0000 (11:17 -0400)
committerDoug Ledford <dledford@redhat.com>
Mon, 22 Aug 2016 18:31:34 +0000 (14:31 -0400)
commit967f5db0975696d0973438b48b24e2f3e6b7a61f
treeeeb8e1aaef184bdd08cc088ead5d10add86923c6
parent7055134214e68266df8dd8f9a89cfe5b55d53c2c
IB/hfi1,IB/qib: Fix qp_stats sleep with rcu read lock held

The qp init function does a kzalloc() while holding the RCU
lock that encounters the following warning with a debug kernel
when a cat of the qp_stats is done:

[  231.723948] rcu_scheduler_active = 1, debug_locks = 0
[  231.731939] 3 locks held by cat/11355:
[  231.736492]  #0:  (debugfs_srcu){......}, at: [<ffffffff813001a5>] debugfs_use_file_start+0x5/0x90
[  231.746955]  #1:  (&p->lock){+.+.+.}, at: [<ffffffff81289a6c>] seq_read+0x4c/0x3c0
[  231.755873]  #2:  (rcu_read_lock){......}, at: [<ffffffffa0a0c535>] _qp_stats_seq_start+0x5/0xd0 [hfi1]
[  231.766862]

The init functions do an implicit next which requires the rcu read lock
before the kzalloc().

Fix for both drivers is to change the scope of the init function to only
do the allocation and the initialization of the just allocated iter.

The implict next is moved back into the respective start functions to fix
the issue.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
CC: <stable@vger.kernel.org> # 4.6.x-
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
drivers/infiniband/hw/hfi1/debugfs.c
drivers/infiniband/hw/hfi1/qp.c
drivers/infiniband/hw/qib/qib_debugfs.c
drivers/infiniband/hw/qib/qib_qp.c