Commit 5c99cbf4 authored Mar 05, 2010 by Oleg Nesterov Committed by Linus Torvalds Mar 06, 2010

coredump: set ->group_exit_code for other CLONE_VM tasks too



User visible change.

do_coredump() kills all threads which share the same ->mm but only the
coredumping process gets the proper exit_code.  Other tasks which share
the same ->mm die "silently" and return status == 0 to parent.

This is historical behaviour, not actually a bug.  But I think Frank
Heckenbach rightly dislikes the current behaviour.  Simple test-case:

	#include <stdio.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/wait.h>

	int main(void)
	{
		int stat;

		if (!fork()) {
			if (!vfork())
				kill(getpid(), SIGQUIT);
		}

		wait(&stat);
		printf("stat=%x\n", stat);
		return 0;
	}

Before this patch it prints "stat=0" despite the fact the child was killed
by SIGQUIT.  After this patch the output is "stat=3" which obviously makes
more sense.

Even with this patch, only the task which originates the coredumping gets
"|= 0x80" if the core was actually dumped, but at least the coredumping
signal is visible to do_wait/etc.

Reported-by: Frank Heckenbach <f.heckenbach@fh-soft.de>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 30736a4d

fs/exec.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1561,12 +1561,13 @@ out:
		return ispipe;
		}

		static int zap_process(struct task_struct *start)
		static int zap_process(struct task_struct *start, int exit_code)
		{
		struct task_struct *t;
		int nr = 0;

		start->signal->flags = SIGNAL_GROUP_EXIT;
		start->signal->group_exit_code = exit_code;
		start->signal->group_stop_count = 0;

		t = start;
		@@ -1591,8 +1592,7 @@ static inline int zap_threads(struct task_struct tsk, struct mm_struct mm,
		spin_lock_irq(&tsk->sighand->siglock);
		if (!signal_group_exit(tsk->signal)) {
		mm->core_state = core_state;
		tsk->signal->group_exit_code = exit_code;
		nr = zap_process(tsk);
		nr = zap_process(tsk, exit_code);
		}
		spin_unlock_irq(&tsk->sighand->siglock);
		if (unlikely(nr < 0))
		@@ -1641,7 +1641,7 @@ static inline int zap_threads(struct task_struct tsk, struct mm_struct mm,
		if (p->mm) {
		if (unlikely(p->mm == mm)) {
		lock_task_sighand(p, &flags);
		nr += zap_process(p);
		nr += zap_process(p, exit_code);
		unlock_task_sighand(p, &flags);
		}
		break;

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