From: Bernd Edlinger bernd.edlinger@hotmail.de
[ Upstream commit 76518d3798855242817e8a8ed76b2d72f4415624 ]
This changes do_io_accounting to use the new exec_update_mutex instead of cred_guard_mutex.
This fixes possible deadlocks when the trace is accessing /proc/$pid/io for instance.
This should be safe, as the credentials are only used for reading.
Signed-off-by: Bernd Edlinger bernd.edlinger@hotmail.de Signed-off-by: Eric W. Biederman ebiederm@xmission.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/proc/base.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c index 4fdfe4faa74ee..529d0c6ec6f9c 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2770,7 +2770,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh unsigned long flags; int result;
- result = mutex_lock_killable(&task->signal->cred_guard_mutex); + result = mutex_lock_killable(&task->signal->exec_update_mutex); if (result) return result;
@@ -2806,7 +2806,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh result = 0;
out_unlock: - mutex_unlock(&task->signal->cred_guard_mutex); + mutex_unlock(&task->signal->exec_update_mutex); return result; }