[Patch] fs/binfmt_elf.c: fix wrong return values

[WANG Cong <xiyou.wangcong@gmail.com>]

When strnlen_user() fails, return 0 is suspecious.
What's more, the caller returns 0 on success, so that logic is
obviously wrong.

I am not sure if returning -EINVAL is good enough. I think it's
better than -EFAULT here.

NOTE: This patch is _not_ tested yet!

Signed-off-by: WANG Cong <wangcong@zeuux.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>

---
 fs/binfmt_elf.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 43254e3..10f9642 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -256,7 +256,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 			return -EFAULT;
 		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 		if (!len || len > MAX_ARG_STRLEN)
-			return 0;
+			return -EINVAL;
 		p += len;
 	}
 	if (__put_user(0, argv))
@@ -268,7 +268,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 			return -EFAULT;
 		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 		if (!len || len > MAX_ARG_STRLEN)
-			return 0;
+			return -EINVAL;
 		p += len;
 	}
 	if (__put_user(0, envp))
-- 
1.5.4.1