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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c143
1 files changed, 90 insertions, 53 deletions
diff --git a/fs/namei.c b/fs/namei.c
index bc35b02883bb..96ca11dea4a2 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -118,15 +118,6 @@
* POSIX.1 2.4: an empty pathname is invalid (ENOENT).
* PATH_MAX includes the nul terminator --RR.
*/
-void final_putname(struct filename *name)
-{
- if (name->separate) {
- __putname(name->name);
- kfree(name);
- } else {
- __putname(name);
- }
-}
#define EMBEDDED_NAME_MAX (PATH_MAX - sizeof(struct filename))
@@ -145,6 +136,7 @@ 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
@@ -179,6 +171,7 @@ recopy:
}
result->name = kname;
result->separate = true;
+ result->refcnt = 1;
max = PATH_MAX;
goto recopy;
}
@@ -202,7 +195,7 @@ recopy:
return result;
error:
- final_putname(result);
+ putname(result);
return err;
}
@@ -212,43 +205,56 @@ getname(const char __user * filename)
return getname_flags(filename, 0, NULL);
}
-/*
- * The "getname_kernel()" interface doesn't do pathnames longer
- * than EMBEDDED_NAME_MAX. Deal with it - you're a kernel user.
- */
struct filename *
getname_kernel(const char * filename)
{
struct filename *result;
- char *kname;
- int len;
-
- len = strlen(filename);
- if (len >= EMBEDDED_NAME_MAX)
- return ERR_PTR(-ENAMETOOLONG);
+ int len = strlen(filename) + 1;
result = __getname();
if (unlikely(!result))
return ERR_PTR(-ENOMEM);
- kname = (char *)result + sizeof(*result);
- result->name = kname;
+ if (len <= EMBEDDED_NAME_MAX) {
+ result->name = (char *)(result) + sizeof(*result);
+ result->separate = false;
+ } else if (len <= PATH_MAX) {
+ struct filename *tmp;
+
+ tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+ if (unlikely(!tmp)) {
+ __putname(result);
+ return ERR_PTR(-ENOMEM);
+ }
+ tmp->name = (char *)result;
+ tmp->separate = true;
+ result = tmp;
+ } else {
+ __putname(result);
+ return ERR_PTR(-ENAMETOOLONG);
+ }
+ memcpy((char *)result->name, filename, len);
result->uptr = NULL;
result->aname = NULL;
- result->separate = false;
+ result->refcnt = 1;
+ audit_getname(result);
- strlcpy(kname, filename, EMBEDDED_NAME_MAX);
return result;
}
-#ifdef CONFIG_AUDITSYSCALL
void putname(struct filename *name)
{
- if (unlikely(!audit_dummy_context()))
- return audit_putname(name);
- final_putname(name);
+ BUG_ON(name->refcnt <= 0);
+
+ if (--name->refcnt > 0)
+ return;
+
+ if (name->separate) {
+ __putname(name->name);
+ kfree(name);
+ } else
+ __putname(name);
}
-#endif
static int check_acl(struct inode *inode, int mask)
{
@@ -2036,31 +2042,47 @@ static int filename_lookup(int dfd, struct filename *name,
static int do_path_lookup(int dfd, const char *name,
unsigned int flags, struct nameidata *nd)
{
- struct filename filename = { .name = name };
+ struct filename *filename = getname_kernel(name);
+ int retval = PTR_ERR(filename);
- return filename_lookup(dfd, &filename, flags, nd);
+ 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)
{
+ struct filename *filename = getname_kernel(name);
struct nameidata nd;
struct dentry *d;
- int err = do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, &nd);
- if (err)
- return ERR_PTR(err);
+ int err;
+
+ if (IS_ERR(filename))
+ return ERR_CAST(filename);
+
+ err = filename_lookup(AT_FDCWD, filename, LOOKUP_PARENT, &nd);
+ if (err) {
+ d = ERR_PTR(err);
+ goto out;
+ }
if (nd.last_type != LAST_NORM) {
path_put(&nd.path);
- return ERR_PTR(-EINVAL);
+ d = ERR_PTR(-EINVAL);
+ goto out;
}
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
d = __lookup_hash(&nd.last, nd.path.dentry, 0);
if (IS_ERR(d)) {
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
- return d;
+ goto out;
}
*path = nd.path;
+out:
+ putname(filename);
return d;
}
@@ -2351,13 +2373,17 @@ static int
filename_mountpoint(int dfd, struct filename *s, struct path *path,
unsigned int flags)
{
- int error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);
+ int error;
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);
if (unlikely(error == -ECHILD))
error = path_mountpoint(dfd, s->name, path, flags);
if (unlikely(error == -ESTALE))
error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_REVAL);
if (likely(!error))
audit_inode(s, path->dentry, 0);
+ putname(s);
return error;
}
@@ -2379,21 +2405,14 @@ int
user_path_mountpoint_at(int dfd, const char __user *name, unsigned int flags,
struct path *path)
{
- struct filename *s = getname(name);
- int error;
- if (IS_ERR(s))
- return PTR_ERR(s);
- error = filename_mountpoint(dfd, s, path, flags);
- putname(s);
- return error;
+ return filename_mountpoint(dfd, getname(name), path, flags);
}
int
kern_path_mountpoint(int dfd, const char *name, struct path *path,
unsigned int flags)
{
- struct filename s = {.name = name};
- return filename_mountpoint(dfd, &s, path, flags);
+ return filename_mountpoint(dfd, getname_kernel(name), path, flags);
}
EXPORT_SYMBOL(kern_path_mountpoint);
@@ -3273,7 +3292,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
{
struct nameidata nd;
struct file *file;
- struct filename filename = { .name = name };
+ struct filename *filename;
int flags = op->lookup_flags | LOOKUP_ROOT;
nd.root.mnt = mnt;
@@ -3282,15 +3301,20 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
if (d_is_symlink(dentry) && op->intent & LOOKUP_OPEN)
return ERR_PTR(-ELOOP);
- file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_RCU);
+ filename = getname_kernel(name);
+ if (unlikely(IS_ERR(filename)))
+ return ERR_CAST(filename);
+
+ file = path_openat(-1, filename, &nd, op, flags | LOOKUP_RCU);
if (unlikely(file == ERR_PTR(-ECHILD)))
- file = path_openat(-1, &filename, &nd, op, flags);
+ file = path_openat(-1, filename, &nd, op, flags);
if (unlikely(file == ERR_PTR(-ESTALE)))
- file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_REVAL);
+ file = path_openat(-1, filename, &nd, op, flags | LOOKUP_REVAL);
+ putname(filename);
return file;
}
-struct dentry *kern_path_create(int dfd, const char *pathname,
+static struct dentry *filename_create(int dfd, struct filename *name,
struct path *path, unsigned int lookup_flags)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
@@ -3305,7 +3329,7 @@ struct dentry *kern_path_create(int dfd, const char *pathname,
*/
lookup_flags &= LOOKUP_REVAL;
- error = do_path_lookup(dfd, pathname, LOOKUP_PARENT|lookup_flags, &nd);
+ error = filename_lookup(dfd, name, LOOKUP_PARENT|lookup_flags, &nd);
if (error)
return ERR_PTR(error);
@@ -3359,6 +3383,19 @@ out:
path_put(&nd.path);
return dentry;
}
+
+struct dentry *kern_path_create(int dfd, const char *pathname,
+ struct path *path, unsigned int lookup_flags)
+{
+ struct filename *filename = getname_kernel(pathname);
+ struct dentry *res;
+
+ if (IS_ERR(filename))
+ return ERR_CAST(filename);
+ res = filename_create(dfd, filename, path, lookup_flags);
+ putname(filename);
+ return res;
+}
EXPORT_SYMBOL(kern_path_create);
void done_path_create(struct path *path, struct dentry *dentry)
@@ -3377,7 +3414,7 @@ struct dentry *user_path_create(int dfd, const char __user *pathname,
struct dentry *res;
if (IS_ERR(tmp))
return ERR_CAST(tmp);
- res = kern_path_create(dfd, tmp->name, path, lookup_flags);
+ res = filename_create(dfd, tmp, path, lookup_flags);
putname(tmp);
return res;
}