[PATCH 3/4] panthor: save task pid and comm in panthor_file

[Chia-I Wu]

We would like to report them on gpu errors.

Signed-off-by: Chia-I Wu <olvaffe@xxxxxxxxx>
---
 drivers/gpu/drm/panthor/panthor_device.h | 6 ++++++
 drivers/gpu/drm/panthor/panthor_drv.c    | 9 +++++++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index 75ae6fd3a5128..8c31c1d4296b6 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -257,6 +257,12 @@ struct panthor_file {
 	/** @stats: cycle and timestamp measures for job execution. */
 	struct panthor_gpu_usage stats;
 
+	/** @pid: pid of the task created this file */
+	pid_t pid;
+
+	/** @comm: comm of the task created this file */
+	char *comm;
+
 	/** @refcount: ref count of this file */
 	struct kref refcount;
 };
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index aea9609684b77..b9d86b86591db 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1400,6 +1400,7 @@ void panthor_file_release(struct kref *kref)
 
 	WARN_ON(pfile->vms || pfile->groups);
 
+	kfree(pfile->comm);
 	kfree(pfile);
 }
 
@@ -1408,6 +1409,7 @@ panthor_open(struct drm_device *ddev, struct drm_file *file)
 {
 	struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
 	struct panthor_file *pfile;
+	struct task_struct *task;
 	int ret;
 
 	pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
@@ -1436,6 +1438,13 @@ panthor_open(struct drm_device *ddev, struct drm_file *file)
 	if (ret)
 		goto err_destroy_vm_pool;
 
+	task = get_pid_task(rcu_access_pointer(file->pid), PIDTYPE_PID);
+	if (task) {
+		pfile->pid = task->pid;
+		pfile->comm = kstrdup(task->comm, GFP_KERNEL);
+		put_task_struct(task);
+	}
+
 	kref_init(&pfile->refcount);
 
 	file->driver_priv = pfile;
-- 
2.50.0.714.g196bf9f422-goog