From 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 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 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 Cc: Cc: Signed-off-by: Andrew Morton Signed-off-by: Christoph Hellwig --- fs/stat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/stat.c') diff --git a/fs/stat.c b/fs/stat.c index 78a3aa8..8806b89 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -294,15 +294,16 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, { struct path path; int error; + int empty = 0; if (bufsiz <= 0) return -EINVAL; - error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path); + error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty); if (!error) { struct inode *inode = path.dentry->d_inode; - error = -EINVAL; + error = empty ? -ENOENT : -EINVAL; if (inode->i_op->readlink) { error = security_inode_readlink(path.dentry); if (!error) { -- cgit v1.1