7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shixiong Ou commit 28cc4d5a75bb07d0eb2fa178db355b04483f5aca upstream. The DRM scheduler KUnit tests pass NULL for the dev field in drm_sched_init_args, which NULL-pointer dereferences in the drm_sched_job trace event via dev_name() on sched->dev. Give the mock scheduler a device with kunit_device_register(), which is also cleaned up at test exit. A per-function counter keeps the device names unique, since some tests create several mock schedulers. Fixes: 5a99350794fe ("drm/sched: Add scheduler unit testing infrastructure and some basic tests") Cc: stable@vger.kernel.org Signed-off-by: Shixiong Ou Acked-by: Maxime Ripard [phasta: removed static variable init to 0 again] Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20260908055941.351486-1-oushixiong1025@163.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/scheduler/tests/mock_scheduler.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c +++ b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2025 Valve Corporation */ +#include + #include "sched_tests.h" /* @@ -288,6 +290,7 @@ static const struct drm_sched_backend_op */ struct drm_mock_scheduler *drm_mock_sched_new(struct kunit *test, long timeout) { + static unsigned int instance; struct drm_sched_init_args args = { .ops = &drm_mock_scheduler_ops, .num_rqs = DRM_SCHED_PRIORITY_COUNT, @@ -297,11 +300,19 @@ struct drm_mock_scheduler *drm_mock_sche .name = "drm-mock-scheduler", }; struct drm_mock_scheduler *sched; + struct device *dev; + char name[64]; int ret; sched = kunit_kzalloc(test, sizeof(*sched), GFP_KERNEL); KUNIT_ASSERT_NOT_NULL(test, sched); + snprintf(name, sizeof(name), "%s-%u", args.name, instance++); + dev = kunit_device_register(test, name); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev); + + args.dev = dev; + ret = drm_sched_init(&sched->base, &args); KUNIT_ASSERT_EQ(test, ret, 0);