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| author | Tejun Heo <tj@kernel.org> | 2018-03-14 12:10:17 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-22 09:18:00 +0100 |
| commit | 48226104275c0d8ddf307e432de8f6e6c5316bff (patch) | |
| tree | a1fa9d6ea14b3fa044eb95a66ac4b203d85d7fa9 /tools/perf/util/scripting-engines/trace-event-python.c | |
| parent | 05f16fe9ae8c18f461b25fd6f31c77333c739f58 (diff) | |
fs/aio: Add explicit RCU grace period when freeing kioctx
commit a6d7cff472eea87d96899a20fa718d2bab7109f3 upstream.
While fixing refcounting, e34ecee2ae79 ("aio: Fix a trinity splat")
incorrectly removed explicit RCU grace period before freeing kioctx.
The intention seems to be depending on the internal RCU grace periods
of percpu_ref; however, percpu_ref uses a different flavor of RCU,
sched-RCU. This can lead to kioctx being freed while RCU read
protected dereferences are still in progress.
Fix it by updating free_ioctx() to go through call_rcu() explicitly.
v2: Comment added to explain double bouncing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Fixes: e34ecee2ae79 ("aio: Fix a trinity splat")
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/util/scripting-engines/trace-event-python.c')
0 files changed, 0 insertions, 0 deletions