* 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)
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);
}
/*
* 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 *
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;
return ERR_PTR(-ENOMEM);
}
tmp->name = (char *)result;
- tmp->separate = true;
result = tmp;
} else {
__putname(result);
if (--name->refcnt > 0)
return;
- if (name->separate) {
+ if (name->name != name->iname) {
__putname(name->name);
kfree(name);
} else
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;
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);
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);
dentry = f.file->f_path.dentry;
- if (*name) {
+ if (*s) {
if (!d_can_lookup(dentry)) {
fdput(f);
return -ENOTDIR;
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)
}
/* 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;
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)
{
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);
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);
* @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)
{
* 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;
}
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;
}
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;
goto out;
}
- error = path_init(dfd, pathname->name, flags, nd);
+ error = path_init(dfd, pathname, flags, nd);
if (unlikely(error))
goto out;
projects / linux-2.6-block.git / blobdiff