lkml.org 
[lkml]   [2009]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [TOMOYO #14 (mmotm 2008-12-30-16-05) 03/10] Introduce d_realpath().
From
Date
James Morris wrote:
> > (3) /proc/PID/ is represented as /proc/self/ if PID equals current->tgid.
>
> This needs an ack from Al and/or Christoph.
>
It is a sad thing that I cannot use /proc/self/ (which is the only part where
a pathname based access control can prevent current process from accessing
other process's information), but I purged d_realpath() for now.

Next posting (#15) will embed AppArmor's d_namespace_path()-like function
into TOMOYO's code.

/* d_namespace_path() in OpenSUSE 11.1's 2.6.27.7-9.1 kernel. */
char *d_namespace_path(struct dentry *dentry, struct vfsmount *vfsmnt,
char *buf, int buflen)
{
struct path root, tmp, ns_root = { };
struct path path = { .mnt = vfsmnt, .dentry = dentry };
char *res;

read_lock(&current->fs->lock);
root = current->fs->root;
path_get(&current->fs->root);
read_unlock(&current->fs->lock);
spin_lock(&vfsmount_lock);
if (root.mnt && root.mnt->mnt_ns)
ns_root.mnt = mntget(root.mnt->mnt_ns->root);
if (ns_root.mnt)
ns_root.dentry = dget(ns_root.mnt->mnt_root);
spin_unlock(&vfsmount_lock);
tmp = ns_root;
res = __d_path(&path, &tmp, buf, buflen,
D_PATH_FAIL_DELETED | D_PATH_DISCONNECT);
path_put(&root);
path_put(&ns_root);

/* Prevent empty path for lazily unmounted filesystems. */
if (!IS_ERR(res) && *res == '\0')
*--res = '.';
return res;
}

Thanks.


\
 
 \ /
  Last update: 2009-01-14 10:01    [W:0.194 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site