6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
commit 9d824c7fce58f59982228aa85b0376b113cdfa35 upstream.
We forgot to disable preemption around the write_seqcount_begin/end() pair
while updating GPU stats:
[ ] WARNING: CPU: 2 PID: 12 at include/linux/seqlock.h:221 __seqprop_assert.isra.0+0x128/0x150 [v3d]
[ ] Workqueue: v3d_bin drm_sched_run_job_work [gpu_sched]
<...snip...>
[ ] Call trace:
[ ] __seqprop_assert.isra.0+0x128/0x150 [v3d]
[ ] v3d_job_start_stats.isra.0+0x90/0x218 [v3d]
[ ] v3d_bin_job_run+0x23c/0x388 [v3d]
[ ] drm_sched_run_job_work+0x520/0x6d0 [gpu_sched]
[ ] process_one_work+0x62c/0xb48
[ ] worker_thread+0x468/0x5b0
[ ] kthread+0x1c4/0x1e0
[ ] ret_from_fork+0x10/0x20
Fix it.
Cc: Maíra Canal <mcanal@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v6.10+
Fixes: 6abe93b621ab ("drm/v3d: Fix race-condition between sysfs/fdinfo and interrupt handler")
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
Acked-by: Maíra Canal <mcanal@xxxxxxxxxx>
Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240813102505.80512-1-tursulin@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/v3d/v3d_sched.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index b8682818bafa..ad1e6236ff6f 100644
--- a/drivers/gpu/drm/v3d/v3d_sched.c
+++ b/drivers/gpu/drm/v3d/v3d_sched.c
@@ -134,6 +134,8 @@ v3d_job_start_stats(struct v3d_job *job, enum v3d_queue queue)
struct v3d_stats *local_stats = &file->stats[queue];
u64 now = local_clock();
+ preempt_disable();
+
write_seqcount_begin(&local_stats->lock);
local_stats->start_ns = now;
write_seqcount_end(&local_stats->lock);
@@ -141,6 +143,8 @@ v3d_job_start_stats(struct v3d_job *job, enum v3d_queue queue)
write_seqcount_begin(&global_stats->lock);
global_stats->start_ns = now;
write_seqcount_end(&global_stats->lock);
+
+ preempt_enable();
}
static void
@@ -162,8 +166,10 @@ v3d_job_update_stats(struct v3d_job *job, enum v3d_queue queue)
struct v3d_stats *local_stats = &file->stats[queue];
u64 now = local_clock();
+ preempt_disable();
v3d_stats_update(local_stats, now);
v3d_stats_update(global_stats, now);
+ preempt_enable();
}
static struct dma_fence *v3d_bin_job_run(struct drm_sched_job *sched_job)
--
2.46.0
