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coredump: set ->group_exit_code for other CLONE_VM tasks too

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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>
This commit is contained in:
Oleg Nesterov
2010-03-05 13:44:14 -08:00
committed by Linus Torvalds
parent 30736a4d43
commit 5c99cbf49a
1 changed files with 4 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
fs/exec.c
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@@ -1561,12 +1561,13 @@ out:
return ispipe; 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; struct task_struct *t;
int nr = 0; int nr = 0;
start->signal->flags = SIGNAL_GROUP_EXIT; start->signal->flags = SIGNAL_GROUP_EXIT;
start->signal->group_exit_code = exit_code;
start->signal->group_stop_count = 0; start->signal->group_stop_count = 0;
t = start; 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); spin_lock_irq(&tsk->sighand->siglock);
if (!signal_group_exit(tsk->signal)) { if (!signal_group_exit(tsk->signal)) {
mm->core_state = core_state; mm->core_state = core_state;
tsk->signal->group_exit_code = exit_code; nr = zap_process(tsk, exit_code);
nr = zap_process(tsk);
} }
spin_unlock_irq(&tsk->sighand->siglock); spin_unlock_irq(&tsk->sighand->siglock);
if (unlikely(nr < 0)) 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 (p->mm) {
if (unlikely(p->mm == mm)) { if (unlikely(p->mm == mm)) {
lock_task_sighand(p, &flags); lock_task_sighand(p, &flags);
nr += zap_process(p); nr += zap_process(p, exit_code);
unlock_task_sighand(p, &flags); unlock_task_sighand(p, &flags);
} }
break; break;