Commit b78709cf authored Jun 26, 2006 by Peter Williams Committed by Linus Torvalds Jun 26, 2006

[PATCH] sched: fix SCHED_FIFO bug in sys_sched_rr_get_interval()



The introduction of SCHED_BATCH scheduling class with a value of 3 means
that the expression (p->policy & SCHED_FIFO) will return true if policy
is SCHED_BATCH or SCHED_FIFO.

Unfortunately, this expression is used in sys_sched_rr_get_interval()
and in the absence of a comment to say that this is intentional I
presume that it is unintentional and erroneous.

The fix is to change the expression to (p->policy == SCHED_FIFO).

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 2139a7fb

kernel/sched.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -4247,7 +4247,7 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
		if (retval)
		goto out_unlock;

		jiffies_to_timespec(p->policy & SCHED_FIFO ?
		jiffies_to_timespec(p->policy == SCHED_FIFO ?
		0 : task_timeslice(p), &t);
		read_unlock(&tasklist_lock);
		retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;

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