*/
void final_putname(struct filename *name)
{
- __putname(name->name);
- kfree(name);
+ if (name->separate) {
+ __putname(name->name);
+ kfree(name);
+ } else {
+ __putname(name);
+ }
}
+#define EMBEDDED_NAME_MAX (PATH_MAX - sizeof(struct filename))
+
static struct filename *
getname_flags(const char __user *filename, int flags, int *empty)
{
struct filename *result, *err;
- char *kname;
int len;
+ long max;
+ char *kname;
- /* FIXME: create dedicated slabcache? */
- result = kzalloc(sizeof(*result), GFP_KERNEL);
+ result = audit_reusename(filename);
+ if (result)
+ return result;
+
+ result = __getname();
if (unlikely(!result))
return ERR_PTR(-ENOMEM);
- kname = __getname();
- if (unlikely(!kname)) {
- err = ERR_PTR(-ENOMEM);
- goto error_free_name;
- }
-
+ /*
+ * First, try to embed the struct filename inside the names_cache
+ * allocation
+ */
+ kname = (char *)result + sizeof(*result);
result->name = kname;
- result->uptr = filename;
- len = strncpy_from_user(kname, filename, PATH_MAX);
+ result->separate = false;
+ max = EMBEDDED_NAME_MAX;
+
+recopy:
+ len = strncpy_from_user(kname, filename, max);
if (unlikely(len < 0)) {
err = ERR_PTR(len);
goto error;
}
+ /*
+ * Uh-oh. We have a name that's approaching PATH_MAX. Allocate a
+ * separate struct filename so we can dedicate the entire
+ * names_cache allocation for the pathname, and re-do the copy from
+ * userland.
+ */
+ if (len == EMBEDDED_NAME_MAX && max == EMBEDDED_NAME_MAX) {
+ kname = (char *)result;
+
+ result = kzalloc(sizeof(*result), GFP_KERNEL);
+ if (!result) {
+ err = ERR_PTR(-ENOMEM);
+ result = (struct filename *)kname;
+ goto error;
+ }
+ result->name = kname;
+ result->separate = true;
+ max = PATH_MAX;
+ goto recopy;
+ }
+
/* The empty path is special. */
if (unlikely(!len)) {
if (empty)
}
err = ERR_PTR(-ENAMETOOLONG);
- if (likely(len < PATH_MAX)) {
- audit_getname(result);
- return result;
- }
+ if (unlikely(len >= PATH_MAX))
+ goto error;
+
+ result->uptr = filename;
+ audit_getname(result);
+ return result;
error:
- __putname(kname);
-error_free_name:
- kfree(result);
+ final_putname(result);
return err;
}
return err;
}
-static int do_path_lookup(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, flags | LOOKUP_RCU, nd);
+ int retval = path_lookupat(dfd, name->name, flags | LOOKUP_RCU, nd);
if (unlikely(retval == -ECHILD))
- retval = path_lookupat(dfd, name, flags, nd);
+ retval = path_lookupat(dfd, name->name, flags, nd);
if (unlikely(retval == -ESTALE))
- retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
+ retval = path_lookupat(dfd, name->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 = { .name = name };
+
+ return filename_lookup(dfd, &filename, flags, nd);
+}
+
/* does lookup, returns the object with parent locked */
struct dentry *kern_path_locked(const char *name, struct path *path)
{
BUG_ON(flags & LOOKUP_PARENT);
- err = do_path_lookup(dfd, tmp->name, flags, &nd);
+ err = filename_lookup(dfd, tmp, flags, &nd);
putname(tmp);
if (!err)
*path = nd.path;
return user_path_at_empty(dfd, name, flags, path, NULL);
}
+/*
+ * NB: most callers don't do anything directly with the reference to the
+ * to struct filename, but the nd->last pointer points into the name string
+ * allocated by getname. So we must hold the reference to it until all
+ * path-walking is complete.
+ */
static struct filename *
user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
{
if (IS_ERR(s))
return s;
- error = do_path_lookup(dfd, s->name, LOOKUP_PARENT, nd);
+ error = filename_lookup(dfd, s, LOOKUP_PARENT, nd);
if (error) {
putname(s);
return ERR_PTR(error);
*/
static int do_last(struct nameidata *nd, struct path *path,
struct file *file, const struct open_flags *op,
- int *opened, const char *pathname)
+ int *opened, struct filename *name)
{
struct dentry *dir = nd->path.dentry;
int open_flag = op->open_flag;
error = complete_walk(nd);
if (error)
return error;
- audit_inode(pathname, nd->path.dentry, 0);
+ audit_inode(name, nd->path.dentry, 0);
if (open_flag & O_CREAT) {
error = -EISDIR;
goto out;
error = complete_walk(nd);
if (error)
return error;
- audit_inode(pathname, dir, 0);
+ audit_inode(name, dir, 0);
goto finish_open;
}
if (error)
return error;
- audit_inode(pathname, dir, 0);
+ audit_inode(name, dir, 0);
error = -EISDIR;
/* trailing slashes? */
if (nd->last.name[nd->last.len])
!S_ISREG(file->f_path.dentry->d_inode->i_mode))
will_truncate = false;
- audit_inode(pathname, file->f_path.dentry, 0);
+ audit_inode(name, file->f_path.dentry, 0);
goto opened;
}
* create/update audit record if it already exists.
*/
if (path->dentry->d_inode)
- audit_inode(pathname, path->dentry, 0);
+ audit_inode(name, path->dentry, 0);
/*
* If atomic_open() acquired write access it is dropped now due to
error = -ENOTDIR;
if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
goto out;
- audit_inode(pathname, nd->path.dentry, 0);
+ audit_inode(name, nd->path.dentry, 0);
finish_open:
if (!S_ISREG(nd->inode->i_mode))
will_truncate = false;
goto retry_lookup;
}
-static struct file *path_openat(int dfd, const char *pathname,
+static struct file *path_openat(int dfd, struct filename *pathname,
struct nameidata *nd, const struct open_flags *op, int flags)
{
struct file *base = NULL;
file->f_flags = op->open_flag;
- error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base);
+ error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base);
if (unlikely(error))
goto out;
current->total_link_count = 0;
- error = link_path_walk(pathname, nd);
+ error = link_path_walk(pathname->name, nd);
if (unlikely(error))
goto out;
return file;
}
-struct file *do_filp_open(int dfd, const char *pathname,
+struct file *do_filp_open(int dfd, struct filename *pathname,
const struct open_flags *op, int flags)
{
struct nameidata nd;
{
struct nameidata nd;
struct file *file;
+ struct filename filename = { .name = name };
nd.root.mnt = mnt;
nd.root.dentry = dentry;
if (dentry->d_inode->i_op->follow_link && op->intent & LOOKUP_OPEN)
return ERR_PTR(-ELOOP);
- file = path_openat(-1, name, &nd, op, flags | LOOKUP_RCU);
+ file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_RCU);
if (unlikely(file == ERR_PTR(-ECHILD)))
- file = path_openat(-1, name, &nd, op, flags);
+ file = path_openat(-1, &filename, &nd, op, flags);
if (unlikely(file == ERR_PTR(-ESTALE)))
- file = path_openat(-1, name, &nd, op, flags | LOOKUP_REVAL);
+ file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_REVAL);
return file;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff