Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 87 insertions, 89 deletions

diff --git a/fs/namei.c b/fs/namei.c
index c83145af4bfc..ffab2e06e147 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -119,15 +119,14 @@
  * PATH_MAX includes the nul terminator --RR.
  */
 
-#define EMBEDDED_NAME_MAX	(PATH_MAX - sizeof(struct filename))
+#define EMBEDDED_NAME_MAX	(PATH_MAX - offsetof(struct filename, iname))
 
 struct filename *
 getname_flags(const char __user *filename, int flags, int *empty)
 {
-	struct filename *result, *err;
-	int len;
-	long max;
+	struct filename *result;
 	char *kname;
+	int len;
 
 	result = audit_reusename(filename);
 	if (result)
@@ -136,22 +135,18 @@ getname_flags(const char __user *filename, int flags, int *empty)
 	result = __getname();
 	if (unlikely(!result))
 		return ERR_PTR(-ENOMEM);
-	result->refcnt = 1;
 
 	/*
 	 * First, try to embed the struct filename inside the names_cache
 	 * allocation
 	 */
-	kname = (char *)result + sizeof(*result);
+	kname = (char *)result->iname;
 	result->name = kname;
-	result->separate = false;
-	max = EMBEDDED_NAME_MAX;
 
-recopy:
-	len = strncpy_from_user(kname, filename, max);
+	len = strncpy_from_user(kname, filename, EMBEDDED_NAME_MAX);
 	if (unlikely(len < 0)) {
-		err = ERR_PTR(len);
-		goto error;
+		__putname(result);
+		return ERR_PTR(len);
 	}
 
 	/*
@@ -160,43 +155,49 @@ recopy:
 	 * names_cache allocation for the pathname, and re-do the copy from
 	 * userland.
 	 */
-	if (len == EMBEDDED_NAME_MAX && max == EMBEDDED_NAME_MAX) {
+	if (unlikely(len == EMBEDDED_NAME_MAX)) {
+		const size_t size = offsetof(struct filename, iname[1]);
 		kname = (char *)result;
 
-		result = kzalloc(sizeof(*result), GFP_KERNEL);
-		if (!result) {
-			err = ERR_PTR(-ENOMEM);
-			result = (struct filename *)kname;
-			goto error;
+		/*
+		 * size is chosen that way we to guarantee that
+		 * result->iname[0] is within the same object and that
+		 * kname can't be equal to result->iname, no matter what.
+		 */
+		result = kzalloc(size, GFP_KERNEL);
+		if (unlikely(!result)) {
+			__putname(kname);
+			return ERR_PTR(-ENOMEM);
 		}
 		result->name = kname;
-		result->separate = true;
-		result->refcnt = 1;
-		max = PATH_MAX;
-		goto recopy;
+		len = strncpy_from_user(kname, filename, PATH_MAX);
+		if (unlikely(len < 0)) {
+			__putname(kname);
+			kfree(result);
+			return ERR_PTR(len);
+		}
+		if (unlikely(len == PATH_MAX)) {
+			__putname(kname);
+			kfree(result);
+			return ERR_PTR(-ENAMETOOLONG);
+		}
 	}
 
+	result->refcnt = 1;
 	/* The empty path is special. */
 	if (unlikely(!len)) {
 		if (empty)
 			*empty = 1;
-		err = ERR_PTR(-ENOENT);
-		if (!(flags & LOOKUP_EMPTY))
-			goto error;
+		if (!(flags & LOOKUP_EMPTY)) {
+			putname(result);
+			return ERR_PTR(-ENOENT);
+		}
 	}
 
-	err = ERR_PTR(-ENAMETOOLONG);
-	if (unlikely(len >= PATH_MAX))
-		goto error;
-
 	result->uptr = filename;
 	result->aname = NULL;
 	audit_getname(result);
 	return result;
-
-error:
-	putname(result);
-	return err;
 }
 
 struct filename *
@@ -216,8 +217,7 @@ getname_kernel(const char * filename)
 		return ERR_PTR(-ENOMEM);
 
 	if (len <= EMBEDDED_NAME_MAX) {
-		result->name = (char *)(result) + sizeof(*result);
-		result->separate = false;
+		result->name = (char *)result->iname;
 	} else if (len <= PATH_MAX) {
 		struct filename *tmp;
 
@@ -227,7 +227,6 @@ getname_kernel(const char * filename)
 			return ERR_PTR(-ENOMEM);
 		}
 		tmp->name = (char *)result;
-		tmp->separate = true;
 		result = tmp;
 	} else {
 		__putname(result);
@@ -249,7 +248,7 @@ void putname(struct filename *name)
 	if (--name->refcnt > 0)
 		return;
 
-	if (name->separate) {
+	if (name->name != name->iname) {
 		__putname(name->name);
 		kfree(name);
 	} else
@@ -1586,7 +1585,7 @@ static inline int walk_component(struct nameidata *nd, struct path *path,
 		inode = path->dentry->d_inode;
 	}
 	err = -ENOENT;
-	if (!inode || d_is_negative(path->dentry))
+	if (d_is_negative(path->dentry))
 		goto out_path_put;
 
 	if (should_follow_link(path->dentry, follow)) {
@@ -1851,10 +1850,11 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 	return err;
 }
 
-static int path_init(int dfd, const char *name, unsigned int flags,
+static int path_init(int dfd, const struct filename *name, unsigned int flags,
 		     struct nameidata *nd)
 {
 	int retval = 0;
+	const char *s = name->name;
 
 	nd->last_type = LAST_ROOT; /* if there are only slashes... */
 	nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
@@ -1863,7 +1863,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 	if (flags & LOOKUP_ROOT) {
 		struct dentry *root = nd->root.dentry;
 		struct inode *inode = root->d_inode;
-		if (*name) {
+		if (*s) {
 			if (!d_can_lookup(root))
 				return -ENOTDIR;
 			retval = inode_permission(inode, MAY_EXEC);
@@ -1885,7 +1885,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 	nd->root.mnt = NULL;
 
 	nd->m_seq = read_seqbegin(&mount_lock);
-	if (*name=='/') {
+	if (*s == '/') {
 		if (flags & LOOKUP_RCU) {
 			rcu_read_lock();
 			nd->seq = set_root_rcu(nd);
@@ -1919,7 +1919,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 
 		dentry = f.file->f_path.dentry;
 
-		if (*name) {
+		if (*s) {
 			if (!d_can_lookup(dentry)) {
 				fdput(f);
 				return -ENOTDIR;
@@ -1949,7 +1949,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 	return -ECHILD;
 done:
 	current->total_link_count = 0;
-	return link_path_walk(name, nd);
+	return link_path_walk(s, nd);
 }
 
 static void path_cleanup(struct nameidata *nd)
@@ -1972,7 +1972,7 @@ static inline int lookup_last(struct nameidata *nd, struct path *path)
 }
 
 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
-static int path_lookupat(int dfd, const char *name,
+static int path_lookupat(int dfd, const struct filename *name,
 				unsigned int flags, struct nameidata *nd)
 {
 	struct path path;
@@ -2027,31 +2027,17 @@ static int path_lookupat(int dfd, const char *name,
 static int filename_lookup(int dfd, struct filename *name,
 				unsigned int flags, struct nameidata *nd)
 {
-	int retval = path_lookupat(dfd, name->name, flags | LOOKUP_RCU, nd);
+	int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
 	if (unlikely(retval == -ECHILD))
-		retval = path_lookupat(dfd, name->name, flags, nd);
+		retval = path_lookupat(dfd, name, flags, nd);
 	if (unlikely(retval == -ESTALE))
-		retval = path_lookupat(dfd, name->name,
-						flags | LOOKUP_REVAL, nd);
+		retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
 
 	if (likely(!retval))
 		audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
 	return retval;
 }
 
-static int do_path_lookup(int dfd, const char *name,
-				unsigned int flags, struct nameidata *nd)
-{
-	struct filename *filename = getname_kernel(name);
-	int retval = PTR_ERR(filename);
-
-	if (!IS_ERR(filename)) {
-		retval = filename_lookup(dfd, filename, flags, nd);
-		putname(filename);
-	}
-	return retval;
-}
-
 /* does lookup, returns the object with parent locked */
 struct dentry *kern_path_locked(const char *name, struct path *path)
 {
@@ -2089,9 +2075,15 @@ out:
 int kern_path(const char *name, unsigned int flags, struct path *path)
 {
 	struct nameidata nd;
-	int res = do_path_lookup(AT_FDCWD, name, flags, &nd);
-	if (!res)
-		*path = nd.path;
+	struct filename *filename = getname_kernel(name);
+	int res = PTR_ERR(filename);
+
+	if (!IS_ERR(filename)) {
+		res = filename_lookup(AT_FDCWD, filename, flags, &nd);
+		putname(filename);
+		if (!res)
+			*path = nd.path;
+	}
 	return res;
 }
 EXPORT_SYMBOL(kern_path);
@@ -2108,15 +2100,22 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 		    const char *name, unsigned int flags,
 		    struct path *path)
 {
-	struct nameidata nd;
-	int err;
-	nd.root.dentry = dentry;
-	nd.root.mnt = mnt;
+	struct filename *filename = getname_kernel(name);
+	int err = PTR_ERR(filename);
+
 	BUG_ON(flags & LOOKUP_PARENT);
-	/* the first argument of do_path_lookup() is ignored with LOOKUP_ROOT */
-	err = do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, &nd);
-	if (!err)
-		*path = nd.path;
+
+	/* the first argument of filename_lookup() is ignored with LOOKUP_ROOT */
+	if (!IS_ERR(filename)) {
+		struct nameidata nd;
+		nd.root.dentry = dentry;
+		nd.root.mnt = mnt;
+		err = filename_lookup(AT_FDCWD, filename,
+				      flags | LOOKUP_ROOT, &nd);
+		if (!err)
+			*path = nd.path;
+		putname(filename);
+	}
 	return err;
 }
 EXPORT_SYMBOL(vfs_path_lookup);
@@ -2138,9 +2137,7 @@ static struct dentry *lookup_hash(struct nameidata *nd)
  * @len:	maximum length @len should be interpreted to
  *
  * Note that this routine is purely a helper for filesystem usage and should
- * not be called by generic code.  Also note that by using this function the
- * nameidata argument is passed to the filesystem methods and a filesystem
- * using this helper needs to be prepared for that.
+ * not be called by generic code.
  */
 struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 {
@@ -2313,7 +2310,7 @@ mountpoint_last(struct nameidata *nd, struct path *path)
 	mutex_unlock(&dir->d_inode->i_mutex);
 
 done:
-	if (!dentry->d_inode || d_is_negative(dentry)) {
+	if (d_is_negative(dentry)) {
 		error = -ENOENT;
 		dput(dentry);
 		goto out;
@@ -2341,7 +2338,8 @@ out:
  * Returns 0 and "path" will be valid on success; Returns error otherwise.
  */
 static int
-path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags)
+path_mountpoint(int dfd, const struct filename *name, struct path *path,
+		unsigned int flags)
 {
 	struct nameidata nd;
 	int err;
@@ -2370,20 +2368,20 @@ out:
 }
 
 static int
-filename_mountpoint(int dfd, struct filename *s, struct path *path,
+filename_mountpoint(int dfd, struct filename *name, struct path *path,
 			unsigned int flags)
 {
 	int error;
-	if (IS_ERR(s))
-		return PTR_ERR(s);
-	error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+	error = path_mountpoint(dfd, name, path, flags | LOOKUP_RCU);
 	if (unlikely(error == -ECHILD))
-		error = path_mountpoint(dfd, s->name, path, flags);
+		error = path_mountpoint(dfd, name, path, flags);
 	if (unlikely(error == -ESTALE))
-		error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_REVAL);
+		error = path_mountpoint(dfd, name, path, flags | LOOKUP_REVAL);
 	if (likely(!error))
-		audit_inode(s, path->dentry, 0);
-	putname(s);
+		audit_inode(name, path->dentry, 0);
+	putname(name);
 	return error;
 }
 
@@ -3040,7 +3038,7 @@ retry_lookup:
 finish_lookup:
 	/* we _can_ be in RCU mode here */
 	error = -ENOENT;
-	if (!inode || d_is_negative(path->dentry)) {
+	if (d_is_negative(path->dentry)) {
 		path_to_nameidata(path, nd);
 		goto out;
 	}
@@ -3079,7 +3077,7 @@ finish_open:
 	error = -ENOTDIR;
 	if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry))
 		goto out;
-	if (!S_ISREG(nd->inode->i_mode))
+	if (!d_is_reg(nd->path.dentry))
 		will_truncate = false;
 
 	if (will_truncate) {
@@ -3156,7 +3154,7 @@ static int do_tmpfile(int dfd, struct filename *pathname,
 	static const struct qstr name = QSTR_INIT("/", 1);
 	struct dentry *dentry, *child;
 	struct inode *dir;
-	int error = path_lookupat(dfd, pathname->name,
+	int error = path_lookupat(dfd, pathname,
 				  flags | LOOKUP_DIRECTORY, nd);
 	if (unlikely(error))
 		return error;
@@ -3229,7 +3227,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
 		goto out;
 	}
 
-	error = path_init(dfd, pathname->name, flags, nd);
+	error = path_init(dfd, pathname, flags, nd);
 	if (unlikely(error))
 		goto out;