Showing who is the current master is useful for trying to decypher
errors when trying to acquire master (e.g. a race with X taking over
from plymouth). By including the process name as well as the pid
simplifies the task of grabbing enough information remotely at the point
of error.
v2: Add the command column header and flesh out a couple of comments.
(David Herrmann)
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: David Herrmann <dh.herrmann at gmail.com>
Reviewed-by: David Herrmann <dh.herrmann at gmail.com>
---
drivers/gpu/drm/drm_info.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c
index 15ec9f471ece..36aba980ea8b 100644
--- a/drivers/gpu/drm/drm_info.c
+++ b/drivers/gpu/drm/drm_info.c
@@ -183,15 +183,32 @@ int drm_clients_info(struct seq_file *m, void *data)
struct drm_device *dev = node->minor->dev;
struct drm_file *priv;
+ seq_printf(m,
+ "%20s %5s %3s master a %5s %10s\n",
+ "command",
+ "pid",
+ "dev",
+ "uid",
+ "magic");
+
+ /* dev->filelist is sorted youngest first, but we want to present
+ * oldest first (i.e. kernel, servers, clients), so walk backwardss.
+ */
mutex_lock(&dev->struct_mutex);
- seq_printf(m, "a dev pid uid magic\n\n");
- list_for_each_entry(priv, &dev->filelist, lhead) {
- seq_printf(m, "%c %3d %5d %5d %10u\n",
- priv->authenticated ? 'y' : 'n',
- priv->minor->index,
+ list_for_each_entry_reverse(priv, &dev->filelist, lhead) {
+ struct task_struct *task;
+
+ rcu_read_lock(); /* locks pid_task()->comm */
+ task = pid_task(priv->pid, PIDTYPE_PID);
+ seq_printf(m, "%20s %5d %3d %c %c %5d %10u\n",
+ task ? task->comm : "<unknown>",
pid_vnr(priv->pid),
+ priv->minor->index,
+ priv->is_master ? 'y' : 'n',
+ priv->authenticated ? 'y' : 'n',
from_kuid_munged(seq_user_ns(m), priv->uid),
priv->magic);
+ rcu_read_unlock();
}
mutex_unlock(&dev->struct_mutex);
return 0;
--
2.1.0
