From 0e5cfc4b93cbdf1d155a7f8e0453c3788a18a2a8 Mon Sep 17 00:00:00 2001
From: Andy Whitcroft <apw@canonical.com>
Date: Wed, 2 Nov 2011 09:44:39 +0100
Subject: [PATCH] --- yaml --- r: 273190 b: refs/heads/master c:
 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 h: refs/heads/master v: v3

---
 [refs]                      |  2 +-
 trunk/fs/namei.c            | 18 +++++++++++++-----
 trunk/fs/stat.c             |  5 +++--
 trunk/include/linux/namei.h |  1 +
 4 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index b8f719789597..df49f22308ec 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 32096ea1aac14e6f29d4744924092eca52b937b0
+refs/heads/master: 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index 7657be4352bf..ac6d214da827 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -137,7 +137,7 @@ static int do_getname(const char __user *filename, char *page)
 	return retval;
 }
 
-static char *getname_flags(const char __user * filename, int flags)
+static char *getname_flags(const char __user *filename, int flags, int *empty)
 {
 	char *tmp, *result;
 
@@ -148,6 +148,8 @@ static char *getname_flags(const char __user * filename, int flags)
 
 		result = tmp;
 		if (retval < 0) {
+			if (retval == -ENOENT && empty)
+				*empty = 1;
 			if (retval != -ENOENT || !(flags & LOOKUP_EMPTY)) {
 				__putname(tmp);
 				result = ERR_PTR(retval);
@@ -160,7 +162,7 @@ static char *getname_flags(const char __user * filename, int flags)
 
 char *getname(const char __user * filename)
 {
-	return getname_flags(filename, 0);
+	return getname_flags(filename, 0, 0);
 }
 
 #ifdef CONFIG_AUDITSYSCALL
@@ -1798,11 +1800,11 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 	return __lookup_hash(&this, base, NULL);
 }
 
-int user_path_at(int dfd, const char __user *name, unsigned flags,
-		 struct path *path)
+int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
+		 struct path *path, int *empty)
 {
 	struct nameidata nd;
-	char *tmp = getname_flags(name, flags);
+	char *tmp = getname_flags(name, flags, empty);
 	int err = PTR_ERR(tmp);
 	if (!IS_ERR(tmp)) {
 
@@ -1816,6 +1818,12 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
 	return err;
 }
 
+int user_path_at(int dfd, const char __user *name, unsigned flags,
+		 struct path *path)
+{
+	return user_path_at_empty(dfd, name, flags, path, 0);
+}
+
 static int user_path_parent(int dfd, const char __user *path,
 			struct nameidata *nd, char **name)
 {
diff --git a/trunk/fs/stat.c b/trunk/fs/stat.c
index 78a3aa83c7ea..8806b8997d2e 100644
--- a/trunk/fs/stat.c
+++ b/trunk/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) {
diff --git a/trunk/include/linux/namei.h b/trunk/include/linux/namei.h
index 409328d1cbbb..ffc02135c483 100644
--- a/trunk/include/linux/namei.h
+++ b/trunk/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)