From b0917c31699319f0b0ce0747e26bd66e8ed83491 Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Wed, 2 Nov 2011 09:44:39 +0100 Subject: readlinkat: ensure we return ENOENT for the empty pathname for normal lookups commit 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 upstream. Since the commit below which added O_PATH support to the *at() calls, the error return for readlink/readlinkat for the empty pathname has switched from ENOENT to EINVAL: commit 65cfc6722361570bfe255698d9cd4dccaf47570d Author: Al Viro Date: Sun Mar 13 15:56:26 2011 -0400 readlinkat(), fchownat() and fstatat() with empty relative pathnames This is both unexpected for userspace and makes readlink/readlinkat inconsistant with all other interfaces; and inconsistant with our stated return for these pathnames. As the readlinkat call does not have a flags parameter we cannot use the AT_EMPTY_PATH approach used in the other calls. Therefore expose whether the original path is infact entry via a new user_path_at_empty() path lookup function. Use this to determine whether to default to EINVAL or ENOENT for failures. Addresses http://bugs.launchpad.net/bugs/817187 [akpm@linux-foundation.org: remove unused getname_flags()] Signed-off-by: Andy Whitcroft Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman --- include/linux/namei.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/namei.h b/include/linux/namei.h index eba45ea..549b7d2 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -67,6 +67,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; #define LOOKUP_EMPTY 0x4000 extern int user_path_at(int, const char __user *, unsigned, struct path *); +extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) -- cgit v1.1