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authorBjörn Steinbrink <B.Steinbrink@gmx.de>2006-09-29 02:00:46 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-29 09:18:16 -0700
commit111dbe0c8a21dffa473239861be47ebc87f593b3 (patch)
treee2bbc7f3abdf3110f0292f0fd0d3a13a0b018dcd
parent3e26a423e78c1bb1ebd29c49d4ae4ccbbacd861b (diff)
[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>
-rw-r--r--kernel/kmod.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 5c470c57fb57..842f8015d7fd 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -176,6 +176,8 @@ static int wait_for_helper(void *data)
if (pid < 0) {
sub_info->retval = pid;
} else {
+ int ret;
+
/*
* Normally it is bogus to call wait4() from in-kernel because
* 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.
*/
- 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);