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Commit 021e1ae3 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
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signals: document CLD_CONTINUED notification mechanics 



A couple of small comments about how CLD_CONTINUED notification works.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7e695a5e

kernel/signal.c

+10 −1
Original line number Diff line number Diff line
@@ -633,6 +633,11 @@ static int prepare_signal(int sig, struct task_struct *p) 
			why |= SIGNAL_CLD_STOPPED;



		if (why) {

			/*

			 * The first thread which returns from finish_stop()

			 * will take ->siglock, notice SIGNAL_CLD_MASK, and

			 * notify its parent. See get_signal_to_deliver().

			 */

			signal->flags = why | SIGNAL_STOP_CONTINUED;

			signal->group_stop_count = 0;

			signal->group_exit_code = 0;
@@ -1694,7 +1699,11 @@ relock: 
	try_to_freeze();



	spin_lock_irq(&sighand->siglock);



	/*

	 * Every stopped thread goes here after wakeup. Check to see if

	 * we should notify the parent, prepare_signal(SIGCONT) encodes

	 * the CLD_ si_code into SIGNAL_CLD_MASK bits.

	 */

	if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {

		int why = (signal->flags & SIGNAL_STOP_CONTINUED)

				? CLD_CONTINUED : CLD_STOPPED;