hexagon: fix strncpy_from_user() error return

It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).

Cc: stable@vger.kernel.org
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h
index f000a38..f61cfb2 100644 (file)
--- a/arch/hexagon/include/asm/uaccess.h
+++ b/arch/hexagon/include/asm/uaccess.h
@@ -103,7 +103,8 @@ static inline long hexagon_strncpy_from_user(char *dst, const char __user *src,
 {
        long res = __strnlen_user(src, n);
 
-       /* return from strnlen can't be zero -- that would be rubbish. */
+       if (unlikely(!res))
+               return -EFAULT;
 
        if (res > n) {
                copy_from_user(dst, src, n);