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| author | Björn Steinbrink <B.Steinbrink@gmx.de> | 2006-09-29 02:00:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-29 09:18:16 -0700 |
| commit | 111dbe0c8a21dffa473239861be47ebc87f593b3 (patch) | |
| tree | e2bbc7f3abdf3110f0292f0fd0d3a13a0b018dcd /kernel/kmod.c | |
| parent | 3e26a423e78c1bb1ebd29c49d4ae4ccbbacd861b (diff) | |
| download | lwn-111dbe0c8a21dffa473239861be47ebc87f593b3.tar.gz lwn-111dbe0c8a21dffa473239861be47ebc87f593b3.zip | |
[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>
Diffstat (limited to 'kernel/kmod.c')
| -rw-r--r-- | kernel/kmod.c | 12 |
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); |