*/
/**
- * unlazy_walk - try to switch to ref-walk mode.
+ * try_to_unlazy - try to switch to ref-walk mode.
* @nd: nameidata pathwalk data
- * Returns: 0 on success, -ECHILD on failure
+ * Returns: true on success, false on failure
*
- * unlazy_walk attempts to legitimize the current nd->path and nd->root
+ * try_to_unlazy attempts to legitimize the current nd->path and nd->root
* for ref-walk mode.
* Must be called from rcu-walk context.
- * Nothing should touch nameidata between unlazy_walk() failure and
+ * Nothing should touch nameidata between try_to_unlazy() failure and
* terminate_walk().
*/
-static int unlazy_walk(struct nameidata *nd)
+static bool try_to_unlazy(struct nameidata *nd)
{
struct dentry *parent = nd->path.dentry;
goto out;
rcu_read_unlock();
BUG_ON(nd->inode != parent->d_inode);
- return 0;
+ return true;
out1:
nd->path.mnt = NULL;
nd->path.dentry = NULL;
out:
rcu_read_unlock();
- return -ECHILD;
+ return false;
}
/**
*/
if (!(nd->flags & (LOOKUP_ROOT | LOOKUP_IS_SCOPED)))
nd->root.mnt = NULL;
- if (unlikely(unlazy_walk(nd)))
+ if (!try_to_unlazy(nd))
return -ECHILD;
}
path_put(&last->link);
}
-int sysctl_protected_symlinks __read_mostly = 0;
-int sysctl_protected_hardlinks __read_mostly = 0;
+int sysctl_protected_symlinks __read_mostly = 1;
+int sysctl_protected_hardlinks __read_mostly = 1;
int sysctl_protected_fifos __read_mostly;
int sysctl_protected_regular __read_mostly;
unsigned seq;
dentry = __d_lookup_rcu(parent, &nd->last, &seq);
if (unlikely(!dentry)) {
- if (unlazy_walk(nd))
+ if (!try_to_unlazy(nd))
return ERR_PTR(-ECHILD);
return NULL;
}
{
if (nd->flags & LOOKUP_RCU) {
int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
- if (err != -ECHILD)
+ if (err != -ECHILD || !try_to_unlazy(nd))
return err;
- if (unlazy_walk(nd))
- return -ECHILD;
}
return inode_permission(nd->inode, MAY_EXEC);
}
// unlazy even if we fail to grab the link - cleanup needs it
bool grabbed_link = legitimize_path(nd, link, seq);
- if (unlazy_walk(nd) != 0 || !grabbed_link)
+ if (!try_to_unlazy(nd) != 0 || !grabbed_link)
return -ECHILD;
if (nd_alloc_stack(nd))
touch_atime(&last->link);
cond_resched();
} else if (atime_needs_update(&last->link, inode)) {
- if (unlikely(unlazy_walk(nd)))
+ if (!try_to_unlazy(nd))
return ERR_PTR(-ECHILD);
touch_atime(&last->link);
}
get = inode->i_op->get_link;
if (nd->flags & LOOKUP_RCU) {
res = get(NULL, inode, &last->done);
- if (res == ERR_PTR(-ECHILD)) {
- if (unlikely(unlazy_walk(nd)))
- return ERR_PTR(-ECHILD);
+ if (res == ERR_PTR(-ECHILD) && try_to_unlazy(nd))
res = get(link->dentry, inode, &last->done);
- }
} else {
res = get(link->dentry, inode, &last->done);
}
return PTR_ERR(name);
while (*name=='/')
name++;
- if (!*name)
+ if (!*name) {
+ nd->dir_mode = 0; // short-circuit the 'hardening' idiocy
return 0;
+ }
/* At this point we know we have a real path component. */
for(;;) {
}
if (unlikely(!d_can_lookup(nd->path.dentry))) {
if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd))
+ if (!try_to_unlazy(nd))
return -ECHILD;
}
return -ENOTDIR;
while (!(err = link_path_walk(s, nd)) &&
(s = lookup_last(nd)) != NULL)
;
+ if (!err && unlikely(nd->flags & LOOKUP_MOUNTPOINT)) {
+ err = handle_lookup_down(nd);
+ nd->flags &= ~LOOKUP_JUMPED; // no d_weak_revalidate(), please...
+ }
if (!err)
err = complete_walk(nd);
if (!err && nd->flags & LOOKUP_DIRECTORY)
if (!d_can_lookup(nd->path.dentry))
err = -ENOTDIR;
- if (!err && unlikely(nd->flags & LOOKUP_MOUNTPOINT)) {
- err = handle_lookup_down(nd);
- nd->flags &= ~LOOKUP_JUMPED; // no d_weak_revalidate(), please...
- }
if (!err) {
*path = nd->path;
nd->path.mnt = NULL;
struct inode *inode;
struct dentry *dentry;
const char *res;
- int error;
nd->flags |= op->intent;
} else {
/* create side of things */
if (nd->flags & LOOKUP_RCU) {
- error = unlazy_walk(nd);
- if (unlikely(error))
- return ERR_PTR(error);
+ if (!try_to_unlazy(nd))
+ return ERR_PTR(-ECHILD);
}
audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
/* trailing slashes? */
}
if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
- error = mnt_want_write(nd->path.mnt);
- if (!error)
- got_write = true;
+ got_write = !mnt_want_write(nd->path.mnt);
/*
* do _not_ fail yet - we might not need that or fail with
* a different error; let lookup_open() decide; we'll be