| From | Ben Hutchings <> | Date | Sun, 16 Jun 2013 23:01:38 +0100 | Subject | [73/83] audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE |
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3.2.47-rc1 review patch. If anyone has any objections, please let me know.
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From: Oleg Nesterov <oleg@redhat.com>
commit f000cfdde5de4fc15dead5ccf524359c07eadf2b upstream.
audit_log_start() does wait_for_auditd() in a loop until audit_backlog_wait_time passes or audit_skb_queue has a room.
If signal_pending() is true this becomes a busy-wait loop, schedule() in TASK_INTERRUPTIBLE won't block.
Thanks to Guy for fully investigating and explaining the problem.
(akpm: that'll cause the system to lock up on a non-preemptible uniprocessor kernel)
(Guy: "Our customer was in fact running a uniprocessor machine, and they reported a system hang.")
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Guy Streeter <streeter@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- kernel/audit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/audit.c +++ b/kernel/audit.c @@ -1167,7 +1167,7 @@ struct audit_buffer *audit_log_start(str /* Wait for auditd to drain the queue a little */ DECLARE_WAITQUEUE(wait, current); - set_current_state(TASK_INTERRUPTIBLE); + set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&audit_backlog_wait, &wait); if (audit_backlog_limit &&
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