Commit d3a532a9 authored Feb 07, 2012 by Anton Vorontsov Committed by Greg Kroah-Hartman Feb 09, 2012

sysrq: Properly check for kernel threads



There's a real possibility of killing kernel threads that might
have issued use_mm(), so kthread's mm might become non-NULL.

This patch fixes the issue by checking for PF_KTHREAD (just as
get_task_mm()).

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e502babe

drivers/tty/sysrq.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -324,8 +324,11 @@ static void send_sig_all(int sig)

		read_lock(&tasklist_lock);
		for_each_process(p) {
		if (p->mm && !is_global_init(p))
		/* Not swapper, init nor kernel thread */
		if (p->flags & PF_KTHREAD)
		continue;
		if (is_global_init(p))
		continue;

		force_sig(sig, p);
		}
		read_unlock(&tasklist_lock);