From 6b55fc63f46ba299f3d84013e9232be4bd259eab Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 2 Oct 2014 12:22:51 +0200 Subject: [PATCH] audit, sched/wait: Fixup kauditd_thread() wait loop The kauditd_thread wait loop is a bit iffy; it has a number of problems: - calls try_to_freeze() before schedule(); you typically want the thread to re-evaluate the sleep condition when unfreezing, also freeze_task() issues a wakeup. - it unconditionally does the {add,remove}_wait_queue(), even when the sleep condition is false. Use wait_event_freezable() that does the right thing. Reported-by: Mike Galbraith Signed-off-by: Peter Zijlstra (Intel) Cc: Eric Paris Cc: oleg@redhat.com Cc: Eric Paris Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20141002102251.GA6324@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- kernel/audit.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 80983df92cd4..32bfc43ffb9a 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -499,7 +499,6 @@ static int kauditd_thread(void *dummy) set_freezable(); while (!kthread_should_stop()) { struct sk_buff *skb; - DECLARE_WAITQUEUE(wait, current); flush_hold_queue(); @@ -514,16 +513,8 @@ static int kauditd_thread(void *dummy) audit_printk_skb(skb); continue; } - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&kauditd_wait, &wait); - if (!skb_queue_len(&audit_skb_queue)) { - try_to_freeze(); - schedule(); - } - - __set_current_state(TASK_RUNNING); - remove_wait_queue(&kauditd_wait, &wait); + wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue)); } return 0; } -- 2.20.1