drm: remove redundant drm_file->uid

Each DRM file-context caches the EUID of the process that opened the file.
It is used exclusively for debugging purposes in /proc/dri/ and friends.

Note, however, that we can already fetch the EUID from
priv->pid->task->creds. The pointer-chasing will not hurt us, since it is
only about debugging, anyway.

Since we already are in an rcu-read-side, we can use __task_cred() rather
than task_cred_xxx().

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160901124837.680-2-dh.herrmann@gmail.com
This commit is contained in:
David Herrmann 2016-09-01 14:48:32 +02:00 committed by Daniel Vetter
parent 9f8cf165c6
commit 75ae95a75d
3 changed files with 3 additions and 3 deletions

View File

@ -199,7 +199,6 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
filp->private_data = priv;
priv->filp = filp;
priv->uid = current_euid();
priv->pid = get_pid(task_pid(current));
priv->minor = minor;

View File

@ -80,6 +80,7 @@ int drm_clients_info(struct seq_file *m, void *data)
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct drm_file *priv;
kuid_t uid;
seq_printf(m,
"%20s %5s %3s master a %5s %10s\n",
@ -98,13 +99,14 @@ int drm_clients_info(struct seq_file *m, void *data)
rcu_read_lock(); /* locks pid_task()->comm */
task = pid_task(priv->pid, PIDTYPE_PID);
uid = task ? __task_cred(task)->euid : GLOBAL_ROOT_UID;
seq_printf(m, "%20s %5d %3d %c %c %5d %10u\n",
task ? task->comm : "<unknown>",
pid_vnr(priv->pid),
priv->minor->index,
drm_is_current_master(priv) ? 'y' : 'n',
priv->authenticated ? 'y' : 'n',
from_kuid_munged(seq_user_ns(m), priv->uid),
from_kuid_munged(seq_user_ns(m), uid),
priv->magic);
rcu_read_unlock();
}

View File

@ -379,7 +379,6 @@ struct drm_file {
unsigned is_master:1;
struct pid *pid;
kuid_t uid;
drm_magic_t magic;
struct list_head lhead;
struct drm_minor *minor;