Re: [PATCH 6/8] drm: use priv->pid to deduce task EUID

On Wed, Aug 03, 2016 at 08:04:30PM +0200, David Herrmann wrote:

Rather than accessing priv->filp->f_cred, use priv->pid->task->creds. We want to get rid of "priv->filp", so lets avoid it if possible.

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

drivers/gpu/drm/drm_info.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c index 247ba2b..1df2d33 100644 --- a/drivers/gpu/drm/drm_info.c +++ b/drivers/gpu/drm/drm_info.c @@ -99,7 +99,7 @@ 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;
  

• uid = task ? __task_cred(task)->euid : GLOBAL_ROOT_UID;
  

Squash this into patch 2, so the poor reader doesn't have to learn about f_cred. -Chris