linux-kernel - [PATCH] drm/sched: warn about drm_sched_job

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241023141530.113370-2-pstanner@redhat.com>
Date: Wed, 23 Oct 2024 16:15:31 +0200
From: Philipp Stanner <pstanner@...hat.com>
To: Luben Tuikov <ltuikov89@...il.com>,
	Matthew Brost <matthew.brost@...el.com>,
	Danilo Krummrich <dakr@...nel.org>,
	Philipp Stanner <pstanner@...hat.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Christian König <christian.koenig@....com>,
	Tvrtko Ursulin <tursulin@...lia.com>
Cc: dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] drm/sched: warn about drm_sched_job_init()'s partial init

drm_sched_job_init()'s name suggests that after the function succeeded,
parameter "job" will be fully initialized. This is not the case; some
members are only later set, notably drm_sched_job.sched by
drm_sched_job_arm().

Document that drm_sched_job_init() does not set all struct members.

Document the lifetime of drm_sched_job.sched.

Signed-off-by: Philipp Stanner <pstanner@...hat.com>
---
 drivers/gpu/drm/scheduler/sched_main.c | 4 ++++
 include/drm/gpu_scheduler.h            | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index dab8cca79eb7..8c1c4739f36d 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -771,6 +771,10 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs);
  * Drivers must make sure drm_sched_job_cleanup() if this function returns
  * successfully, even when @job is aborted before drm_sched_job_arm() is called.
  *
+ * Note that this function does not assign a valid value to each struct member
+ * of struct drm_sched_job. Take a look at that struct's documentation to see
+ * who sets which struct member with what lifetime.
+ *
  * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware
  * has died, which can mean that there's no valid runqueue for a @entity.
  * This function returns -ENOENT in this case (which probably should be -EIO as
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index ab161289d1bf..95e17504e46a 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -340,6 +340,14 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
 struct drm_sched_job {
 	struct spsc_node		queue_node;
 	struct list_head		list;
+
+	/**
+	 * @sched:
+	 *
+	 * The scheduler this job is or will be scheduled on. Gets set by
+	 * drm_sched_job_arm(). Valid until drm_sched_backend_ops.free_job()
+	 * has finished.
+	 */
 	struct drm_gpu_scheduler	*sched;
 	struct drm_sched_fence		*s_fence;
 
-- 
2.47.0