Commit 15b9f360 authored Jul 25, 2008 by Oleg Nesterov Committed by Linus Torvalds Jul 25, 2008

coredump: zap_threads() must skip kernel threads



The main loop in zap_threads() must skip kthreads which may use the same
mm.  Otherwise we "kill" this thread erroneously (for example, it can not
fork or exec after that), and the coredumping task stucks in the
TASK_UNINTERRUPTIBLE state forever because of the wrong ->core_waiters
count.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 246bb0b1

fs/exec.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1574,11 +1574,12 @@ static inline int zap_threads(struct task_struct tsk, struct mm_struct mm,
		for_each_process(g) {
		if (g == tsk->group_leader)
		continue;

		if (g->flags & PF_KTHREAD)
		continue;
		p = g;
		do {
		if (p->mm) {
		if (p->mm == mm) {
		if (unlikely(p->mm == mm)) {
		lock_task_sighand(p, &flags);
		zap_process(p);
		unlock_task_sighand(p, &flags);

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