Files
Linux/kernel/locking
Waiman Long 39e7234f00 locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
The commit 91d2a812df ("locking/rwsem: Make handoff writer
optimistically spin on owner") will allow a recently woken up waiting
writer to spin on the owner. Unfortunately, if the owner happens to be
RWSEM_OWNER_UNKNOWN, the code will incorrectly spin on it leading to a
kernel crash. This is fixed by passing the proper non-spinnable bits
to rwsem_spin_on_owner() so that RWSEM_OWNER_UNKNOWN will be treated
as a non-spinnable target.

Fixes: 91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")

Reported-by: Christoph Hellwig <[email protected]>
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Christoph Hellwig <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
2020-01-17 10:19:27 +01:00
..
2019-08-08 09:09:25 +02:00