[PATCH -mm] c/r: prctl: Return -EFAULT instead of -EINVAL in case if underlied VMA is not found

[Cyrill Gorcunov <gorcunov@openvz.org>]

In case if underlied VMA is not found prctl_set_mm will return -EINVAL,
but Michael proposed to return -EFAULT and Kosaki seconded.
Make it so.

Reported-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>,
Cc: Tejun Heo <tj@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 kernel/sys.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.git/kernel/sys.c
===================================================================
--- linux-2.6.git.orig/kernel/sys.c
+++ linux-2.6.git/kernel/sys.c
@@ -1838,8 +1838,10 @@ static int prctl_set_mm(int opt, unsigne
 	case PR_SET_MM_ARG_END:
 	case PR_SET_MM_ENV_START:
 	case PR_SET_MM_ENV_END:
-		if (!vma)
+		if (!vma) {
+			error = -EFAULT;
 			goto out;
+		}
 #ifdef CONFIG_STACK_GROWSUP
 		if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSUP, 0))
 #else