#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/device_cgroup.h>
-#include <asm/namei.h>
#include <asm/uaccess.h>
#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
{
umode_t mode = inode->i_mode;
+ mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
+
if (current->fsuid == inode->i_uid)
mode >>= 6;
else {
/*
* If the DACs are ok we don't need any capability check.
*/
- if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
+ if ((mask & ~mode) == 0)
return 0;
check_capabilities:
return -EACCES;
}
-int permission(struct inode *inode, int mask, struct nameidata *nd)
+int inode_permission(struct inode *inode, int mask)
{
- int retval, submask;
- struct vfsmount *mnt = NULL;
-
- if (nd)
- mnt = nd->path.mnt;
+ int retval;
if (mask & MAY_WRITE) {
umode_t mode = inode->i_mode;
return -EACCES;
}
- if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
- /*
- * MAY_EXEC on regular files is denied if the fs is mounted
- * with the "noexec" flag.
- */
- if (mnt && (mnt->mnt_flags & MNT_NOEXEC))
- return -EACCES;
- }
-
/* Ordinary permission routines do not understand MAY_APPEND. */
- submask = mask & ~MAY_APPEND;
if (inode->i_op && inode->i_op->permission) {
- retval = inode->i_op->permission(inode, submask, nd);
+ retval = inode->i_op->permission(inode, mask);
if (!retval) {
/*
* Exec permission on a regular file is denied if none
return -EACCES;
}
} else {
- retval = generic_permission(inode, submask, NULL);
+ retval = generic_permission(inode, mask, NULL);
}
if (retval)
return retval;
if (retval)
return retval;
- return security_inode_permission(inode, mask, nd);
+ return security_inode_permission(inode,
+ mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND));
}
/**
*/
int vfs_permission(struct nameidata *nd, int mask)
{
- return permission(nd->path.dentry->d_inode, mask, nd);
+ return inode_permission(nd->path.dentry->d_inode, mask);
}
/**
*/
int file_permission(struct file *file, int mask)
{
- return permission(file->f_path.dentry->d_inode, mask, NULL);
+ return inode_permission(file->f_path.dentry->d_inode, mask);
}
/*
* short-cut DAC fails, then call permission() to do more
* complete permission check.
*/
-static int exec_permission_lite(struct inode *inode,
- struct nameidata *nd)
+static int exec_permission_lite(struct inode *inode)
{
umode_t mode = inode->i_mode;
return -EACCES;
ok:
- return security_inode_permission(inode, MAY_EXEC, nd);
+ return security_inode_permission(inode, MAY_EXEC);
}
/*
*/
result = d_lookup(parent, name);
if (!result) {
- struct dentry * dentry = d_alloc(parent, name);
+ struct dentry *dentry;
+
+ /* Don't create child dentry for a dead directory. */
+ result = ERR_PTR(-ENOENT);
+ if (IS_DEADDIR(dir))
+ goto out_unlock;
+
+ dentry = d_alloc(parent, name);
result = ERR_PTR(-ENOMEM);
if (dentry) {
result = dir->i_op->lookup(dir, dentry, nd);
else
result = dentry;
}
+out_unlock:
mutex_unlock(&dir->i_mutex);
return result;
}
return result;
}
-static int __emul_lookup_dentry(const char *, struct nameidata *);
-
/* SMP-safe */
-static __always_inline int
+static __always_inline void
walk_init_root(const char *name, struct nameidata *nd)
{
struct fs_struct *fs = current->fs;
read_lock(&fs->lock);
- if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
- nd->path = fs->altroot;
- path_get(&fs->altroot);
- read_unlock(&fs->lock);
- if (__emul_lookup_dentry(name,nd))
- return 0;
- read_lock(&fs->lock);
- }
nd->path = fs->root;
path_get(&fs->root);
read_unlock(&fs->lock);
- return 1;
}
/*
int result;
/* make sure the stuff we saved doesn't go away */
- dget(save.dentry);
- mntget(save.mnt);
+ path_get(&save);
result = __link_path_walk(name, nd);
if (result == -ESTALE) {
/* nd->path had been dropped */
nd->path = save;
- dget(nd->path.dentry);
- mntget(nd->path.mnt);
+ path_get(&nd->path);
nd->flags |= LOOKUP_REVAL;
result = __link_path_walk(name, nd);
}
if (*link == '/') {
path_put(&nd->path);
- if (!walk_init_root(link, nd))
- /* weird __emul_prefix() stuff did it */
- goto out;
+ walk_init_root(link, nd);
}
res = link_path_walk(link, nd);
-out:
if (nd->depth || res || nd->last_type!=LAST_NORM)
return res;
/*
unsigned int c;
nd->flags |= LOOKUP_CONTINUE;
- err = exec_permission_lite(inode, nd);
+ err = exec_permission_lite(inode);
if (err == -EAGAIN)
err = vfs_permission(nd, MAY_EXEC);
if (err)
return link_path_walk(name, nd);
}
-/*
- * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if
- * everything is done. Returns 0 and drops input nd, if lookup failed;
- */
-static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
-{
- if (path_walk(name, nd))
- return 0; /* something went wrong... */
-
- if (!nd->path.dentry->d_inode ||
- S_ISDIR(nd->path.dentry->d_inode->i_mode)) {
- struct path old_path = nd->path;
- struct qstr last = nd->last;
- int last_type = nd->last_type;
- struct fs_struct *fs = current->fs;
-
- /*
- * NAME was not found in alternate root or it's a directory.
- * Try to find it in the normal root:
- */
- nd->last_type = LAST_ROOT;
- read_lock(&fs->lock);
- nd->path = fs->root;
- path_get(&fs->root);
- read_unlock(&fs->lock);
- if (path_walk(name, nd) == 0) {
- if (nd->path.dentry->d_inode) {
- path_put(&old_path);
- return 1;
- }
- path_put(&nd->path);
- }
- nd->path = old_path;
- nd->last = last;
- nd->last_type = last_type;
- }
- return 1;
-}
-
-void set_fs_altroot(void)
-{
- char *emul = __emul_prefix();
- struct nameidata nd;
- struct path path = {}, old_path;
- int err;
- struct fs_struct *fs = current->fs;
-
- if (!emul)
- goto set_it;
- err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd);
- if (!err)
- path = nd.path;
-set_it:
- write_lock(&fs->lock);
- old_path = fs->altroot;
- fs->altroot = path;
- write_unlock(&fs->lock);
- if (old_path.dentry)
- path_put(&old_path);
-}
-
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
static int do_path_lookup(int dfd, const char *name,
unsigned int flags, struct nameidata *nd)
if (*name=='/') {
read_lock(&fs->lock);
- if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
- nd->path = fs->altroot;
- path_get(&fs->altroot);
- read_unlock(&fs->lock);
- if (__emul_lookup_dentry(name,nd))
- goto out; /* found in altroot */
- read_lock(&fs->lock);
- }
nd->path = fs->root;
path_get(&fs->root);
read_unlock(&fs->lock);
}
retval = path_walk(name, nd);
-out:
if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
nd->path.dentry->d_inode))
audit_inode(name, nd->path.dentry);
nd->flags = flags;
nd->depth = 0;
- nd->path.mnt = mntget(mnt);
- nd->path.dentry = dget(dentry);
+ nd->path.dentry = dentry;
+ nd->path.mnt = mnt;
+ path_get(&nd->path);
retval = path_walk(name, nd);
if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
nd, open_flags, create_mode);
}
-int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags,
- struct nameidata *nd, int open_flags)
-{
- char *tmp = getname(name);
- int err = PTR_ERR(tmp);
-
- if (!IS_ERR(tmp)) {
- err = __path_lookup_intent_open(AT_FDCWD, tmp, lookup_flags, nd, open_flags, 0);
- putname(tmp);
- }
- return err;
-}
-
static struct dentry *__lookup_hash(struct qstr *name,
struct dentry *base, struct nameidata *nd)
{
dentry = cached_lookup(base, name, nd);
if (!dentry) {
- struct dentry *new = d_alloc(base, name);
+ struct dentry *new;
+
+ /* Don't create child dentry for a dead directory. */
+ dentry = ERR_PTR(-ENOENT);
+ if (IS_DEADDIR(inode))
+ goto out;
+
+ new = d_alloc(base, name);
dentry = ERR_PTR(-ENOMEM);
if (!new)
goto out;
{
int err;
- err = permission(nd->path.dentry->d_inode, MAY_EXEC, nd);
+ err = inode_permission(nd->path.dentry->d_inode, MAY_EXEC);
if (err)
return ERR_PTR(err);
return __lookup_hash(&nd->last, nd->path.dentry, nd);
if (err)
return ERR_PTR(err);
- err = permission(base->d_inode, MAY_EXEC, NULL);
+ err = inode_permission(base->d_inode, MAY_EXEC);
if (err)
return ERR_PTR(err);
return __lookup_hash(&this, base, NULL);
return __lookup_hash(&this, base, NULL);
}
-int __user_walk_fd(int dfd, const char __user *name, unsigned flags,
- struct nameidata *nd)
+int user_path_at(int dfd, const char __user *name, unsigned flags,
+ struct path *path)
{
+ struct nameidata nd;
char *tmp = getname(name);
int err = PTR_ERR(tmp);
-
if (!IS_ERR(tmp)) {
- err = do_path_lookup(dfd, tmp, flags, nd);
+
+ BUG_ON(flags & LOOKUP_PARENT);
+
+ err = do_path_lookup(dfd, tmp, flags, &nd);
putname(tmp);
+ if (!err)
+ *path = nd.path;
}
return err;
}
-int __user_walk(const char __user *name, unsigned flags, struct nameidata *nd)
+static int user_path_parent(int dfd, const char __user *path,
+ struct nameidata *nd, char **name)
{
- return __user_walk_fd(AT_FDCWD, name, flags, nd);
+ char *s = getname(path);
+ int error;
+
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+
+ error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd);
+ if (error)
+ putname(s);
+ else
+ *name = s;
+
+ return error;
}
/*
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(victim->d_name.name, victim, dir);
- error = permission(dir,MAY_WRITE | MAY_EXEC, NULL);
+ error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)
return error;
if (IS_APPEND(dir))
* 3. We should have write and exec permissions on dir
* 4. We can't do it if dir is immutable (done in permission())
*/
-static inline int may_create(struct inode *dir, struct dentry *child,
- struct nameidata *nd)
+static inline int may_create(struct inode *dir, struct dentry *child)
{
if (child->d_inode)
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
- return permission(dir,MAY_WRITE | MAY_EXEC, nd);
+ return inode_permission(dir, MAY_WRITE | MAY_EXEC);
}
/*
int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
- int error = may_create(dir, dentry, nd);
+ int error = may_create(dir, dentry);
if (error)
return error;
int will_write;
int flag = open_to_namei_flags(open_flag);
- acc_mode = ACC_MODE(flag);
+ acc_mode = MAY_OPEN | ACC_MODE(flag);
/* O_TRUNC implies we need access checks for write permissions */
if (flag & O_TRUNC)
if (IS_ERR(dentry))
goto fail;
+ if (dentry->d_inode)
+ goto eexist;
/*
* Special case - lookup gave negative, but... we had foo/bar/
* From the vfs_mknod() POV we just have a negative dentry -
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
- if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
- goto enoent;
+ if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
+ dput(dentry);
+ dentry = ERR_PTR(-ENOENT);
+ }
return dentry;
-enoent:
+eexist:
dput(dentry);
- dentry = ERR_PTR(-ENOENT);
+ dentry = ERR_PTR(-EEXIST);
fail:
return dentry;
}
int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
- int error = may_create(dir, dentry, NULL);
+ int error = may_create(dir, dentry);
if (error)
return error;
asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
unsigned dev)
{
- int error = 0;
- char * tmp;
- struct dentry * dentry;
+ int error;
+ char *tmp;
+ struct dentry *dentry;
struct nameidata nd;
if (S_ISDIR(mode))
return -EPERM;
- tmp = getname(filename);
- if (IS_ERR(tmp))
- return PTR_ERR(tmp);
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, filename, &nd, &tmp);
if (error)
- goto out;
+ return error;
+
dentry = lookup_create(&nd, 0);
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(tmp);
return error;
int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
- int error = may_create(dir, dentry, NULL);
+ int error = may_create(dir, dentry);
if (error)
return error;
struct dentry *dentry;
struct nameidata nd;
- tmp = getname(pathname);
- error = PTR_ERR(tmp);
- if (IS_ERR(tmp))
+ error = user_path_parent(dfd, pathname, &nd, &tmp);
+ if (error)
goto out_err;
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
dentry = lookup_create(&nd, 1);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(tmp);
out_err:
return error;
struct dentry *dentry;
struct nameidata nd;
- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, pathname, &nd, &name);
if (error)
- goto exit;
+ return error;
switch(nd.last_type) {
case LAST_DOTDOT:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
exit1:
path_put(&nd.path);
-exit:
putname(name);
return error;
}
*/
static long do_unlinkat(int dfd, const char __user *pathname)
{
- int error = 0;
- char * name;
+ int error;
+ char *name;
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
- name = getname(pathname);
- if(IS_ERR(name))
- return PTR_ERR(name);
-
- error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
+ error = user_path_parent(dfd, pathname, &nd, &name);
if (error)
- goto exit;
+ return error;
+
error = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
iput(inode); /* truncate the inode here */
exit1:
path_put(&nd.path);
-exit:
putname(name);
return error;
return do_unlinkat(AT_FDCWD, pathname);
}
-int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode)
+int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
{
- int error = may_create(dir, dentry, NULL);
+ int error = may_create(dir, dentry);
if (error)
return error;
asmlinkage long sys_symlinkat(const char __user *oldname,
int newdfd, const char __user *newname)
{
- int error = 0;
- char * from;
- char * to;
+ int error;
+ char *from;
+ char *to;
struct dentry *dentry;
struct nameidata nd;
from = getname(oldname);
- if(IS_ERR(from))
+ if (IS_ERR(from))
return PTR_ERR(from);
- to = getname(newname);
- error = PTR_ERR(to);
- if (IS_ERR(to))
- goto out_putname;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+ error = user_path_parent(newdfd, newname, &nd, &to);
if (error)
- goto out;
+ goto out_putname;
+
dentry = lookup_create(&nd, 0);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
error = mnt_want_write(nd.path.mnt);
if (error)
goto out_dput;
- error = vfs_symlink(nd.path.dentry->d_inode, dentry, from, S_IALLUGO);
+ error = vfs_symlink(nd.path.dentry->d_inode, dentry, from);
mnt_drop_write(nd.path.mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
-out:
putname(to);
out_putname:
putname(from);
if (!inode)
return -ENOENT;
- error = may_create(dir, new_dentry, NULL);
+ error = may_create(dir, new_dentry);
if (error)
return error;
return -EPERM;
if (!dir->i_op || !dir->i_op->link)
return -EPERM;
- if (S_ISDIR(old_dentry->d_inode->i_mode))
+ if (S_ISDIR(inode->i_mode))
return -EPERM;
error = security_inode_link(old_dentry, dir, new_dentry);
if (error)
return error;
- mutex_lock(&old_dentry->d_inode->i_mutex);
+ mutex_lock(&inode->i_mutex);
DQUOT_INIT(dir);
error = dir->i_op->link(old_dentry, dir, new_dentry);
- mutex_unlock(&old_dentry->d_inode->i_mutex);
+ mutex_unlock(&inode->i_mutex);
if (!error)
- fsnotify_link(dir, old_dentry->d_inode, new_dentry);
+ fsnotify_link(dir, inode, new_dentry);
return error;
}
int flags)
{
struct dentry *new_dentry;
- struct nameidata nd, old_nd;
+ struct nameidata nd;
+ struct path old_path;
int error;
- char * to;
+ char *to;
if ((flags & ~AT_SYMLINK_FOLLOW) != 0)
return -EINVAL;
- to = getname(newname);
- if (IS_ERR(to))
- return PTR_ERR(to);
-
- error = __user_walk_fd(olddfd, oldname,
- flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0,
- &old_nd);
+ error = user_path_at(olddfd, oldname,
+ flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0,
+ &old_path);
if (error)
- goto exit;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+ return error;
+
+ error = user_path_parent(newdfd, newname, &nd, &to);
if (error)
goto out;
error = -EXDEV;
- if (old_nd.path.mnt != nd.path.mnt)
+ if (old_path.mnt != nd.path.mnt)
goto out_release;
new_dentry = lookup_create(&nd, 0);
error = PTR_ERR(new_dentry);
error = mnt_want_write(nd.path.mnt);
if (error)
goto out_dput;
- error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry);
+ error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry);
mnt_drop_write(nd.path.mnt);
out_dput:
dput(new_dentry);
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
out_release:
path_put(&nd.path);
-out:
- path_put(&old_nd.path);
-exit:
putname(to);
+out:
+ path_put(&old_path);
return error;
}
* we'll need to flip '..'.
*/
if (new_dir != old_dir) {
- error = permission(old_dentry->d_inode, MAY_WRITE, NULL);
+ error = inode_permission(old_dentry->d_inode, MAY_WRITE);
if (error)
return error;
}
return error;
if (!new_dentry->d_inode)
- error = may_create(new_dir, new_dentry, NULL);
+ error = may_create(new_dir, new_dentry);
else
error = may_delete(new_dir, new_dentry, is_dir);
if (error)
return error;
}
-static int do_rename(int olddfd, const char *oldname,
- int newdfd, const char *newname)
+asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
+ int newdfd, const char __user *newname)
{
- int error = 0;
- struct dentry * old_dir, * new_dir;
- struct dentry * old_dentry, *new_dentry;
- struct dentry * trap;
+ struct dentry *old_dir, *new_dir;
+ struct dentry *old_dentry, *new_dentry;
+ struct dentry *trap;
struct nameidata oldnd, newnd;
+ char *from;
+ char *to;
+ int error;
- error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd);
+ error = user_path_parent(olddfd, oldname, &oldnd, &from);
if (error)
goto exit;
- error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd);
+ error = user_path_parent(newdfd, newname, &newnd, &to);
if (error)
goto exit1;
unlock_rename(new_dir, old_dir);
exit2:
path_put(&newnd.path);
+ putname(to);
exit1:
path_put(&oldnd.path);
-exit:
- return error;
-}
-
-asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
- int newdfd, const char __user *newname)
-{
- int error;
- char * from;
- char * to;
-
- from = getname(oldname);
- if(IS_ERR(from))
- return PTR_ERR(from);
- to = getname(newname);
- error = PTR_ERR(to);
- if (!IS_ERR(to)) {
- error = do_rename(olddfd, from, newdfd, to);
- putname(to);
- }
putname(from);
+exit:
return error;
}
{
struct nameidata nd;
void *cookie;
+ int res;
nd.depth = 0;
cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
- if (!IS_ERR(cookie)) {
- int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
- if (dentry->d_inode->i_op->put_link)
- dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
- cookie = ERR_PTR(res);
- }
- return PTR_ERR(cookie);
+ if (IS_ERR(cookie))
+ return PTR_ERR(cookie);
+
+ res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
+ if (dentry->d_inode->i_op->put_link)
+ dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
+ return res;
}
int vfs_follow_link(struct nameidata *nd, const char *link)
.put_link = page_put_link,
};
-EXPORT_SYMBOL(__user_walk);
-EXPORT_SYMBOL(__user_walk_fd);
+EXPORT_SYMBOL(user_path_at);
EXPORT_SYMBOL(follow_down);
EXPORT_SYMBOL(follow_up);
EXPORT_SYMBOL(get_write_access); /* binfmt_aout */
EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(path_lookup);
EXPORT_SYMBOL(vfs_path_lookup);
-EXPORT_SYMBOL(permission);
+EXPORT_SYMBOL(inode_permission);
EXPORT_SYMBOL(vfs_permission);
EXPORT_SYMBOL(file_permission);
EXPORT_SYMBOL(unlock_rename);