[PATCH] Fix ____call_usermodehelper errors being silently ignored

If ____call_usermodehelper fails, we're not interested in the child
process' exit value, but the real error, so let's stop wait_for_helper from
overwriting it in that case.

Issue discovered by Benedikt Böhm while working on a Linux-VServer usermode
helper.

Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Björn Steinbrink 2006-09-29 02:00:46 -07:00 committed by Linus Torvalds
parent 3e26a423e7
commit 111dbe0c8a

View file

@ -176,6 +176,8 @@ static int wait_for_helper(void *data)
if (pid < 0) { if (pid < 0) {
sub_info->retval = pid; sub_info->retval = pid;
} else { } else {
int ret;
/* /*
* Normally it is bogus to call wait4() from in-kernel because * Normally it is bogus to call wait4() from in-kernel because
* wait4() wants to write the exit code to a userspace address. * wait4() wants to write the exit code to a userspace address.
@ -185,7 +187,15 @@ static int wait_for_helper(void *data)
* *
* Thus the __user pointer cast is valid here. * Thus the __user pointer cast is valid here.
*/ */
sys_wait4(pid, (int __user *) &sub_info->retval, 0, NULL); sys_wait4(pid, (int __user *)&ret, 0, NULL);
/*
* If ret is 0, either ____call_usermodehelper failed and the
* real error code is already in sub_info->retval or
* sub_info->retval is 0 anyway, so don't mess with it then.
*/
if (ret)
sub_info->retval = ret;
} }
complete(sub_info->complete); complete(sub_info->complete);