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 "struct file" already caches the credentials of a
process at open-time. So lets just use drm_file->filp->f_cred->euid if
available. The pointer-chasing will not hurt us, since it is only about
debugging, anyway.
Check priv->filp for NULL before deref, to prepare for in-kernel contexts
(if they ever appear). We should not rely on "struct file" contexts to be
around at all times, anyway.
Signed-off-by: David Herrmann <dh.herrmann at gmail.com>
---
drivers/gpu/drm/drm_fops.c | 1 -
drivers/gpu/drm/drm_info.c | 4 +++-
drivers/gpu/drm/drm_ioctl.c | 4 +++-
include/drm/drmP.h | 1 -
4 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 323c238..e9d66f5 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -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;
diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c
index 9ae353f..247ba2b 100644
--- a/drivers/gpu/drm/drm_info.c
+++ b/drivers/gpu/drm/drm_info.c
@@ -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 = priv->filp ? priv->filp->f_cred->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();
}
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 33af4a5..49cd835 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -191,7 +191,9 @@ static int drm_getclient(struct drm_device *dev, void *data,
client->auth = file_priv->authenticated;
client->pid = pid_vnr(file_priv->pid);
client->uid = from_kuid_munged(current_user_ns(),
- file_priv->uid);
+ file_priv->filp ?
+ file_priv->filp->f_cred->euid :
+ GLOBAL_ROOT_UID);
client->magic = 0;
client->iocs = 0;
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index d488a72..0f69f56 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -320,7 +320,6 @@ 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;
--
2.9.2
