From: Shixiong Ou <[email protected]> The DRM scheduler KUnit tests currently pass NULL for the dev field in drm_sched_init_args, which causes a NULL pointer dereference in the drm_sched_job trace event when it calls dev_name() on sched->dev.
Use faux_device_create() to create a fake device for the mock scheduler, so the scheduler always has a valid device pointer. This avoids the trace event crash without requiring the production code to accept a NULL device pointer, which conceptually makes no sense for a scheduler. An atomic counter is used to generate unique device names, since multiple mock schedulers can exist simultaneously across different test suites. Signed-off-by: Shixiong Ou <[email protected]> --- drivers/gpu/drm/scheduler/tests/mock_scheduler.c | 14 ++++++++++++++ drivers/gpu/drm/scheduler/tests/sched_tests.h | 2 ++ 2 files changed, 16 insertions(+) diff --git a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c index 14403a762335..cd87e405bb1e 100644 --- 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 <linux/device/faux.h> + #include "sched_tests.h" /* @@ -10,6 +12,8 @@ * Test cases are implemented in a separate file. */ +static atomic_t drm_mock_sched_instance = ATOMIC_INIT(0); + /** * drm_mock_sched_entity_new - Create a new mock scheduler entity * @@ -296,11 +300,20 @@ struct drm_mock_scheduler *drm_mock_sched_new(struct kunit *test, long timeout) .name = "drm-mock-scheduler", }; struct drm_mock_scheduler *sched; + char name[64]; int ret; sched = kunit_kzalloc(test, sizeof(*sched), GFP_KERNEL); KUNIT_ASSERT_NOT_NULL(test, sched); + snprintf(name, sizeof(name), "drm-mock-scheduler-%d", + atomic_inc_return(&drm_mock_sched_instance)); + + sched->faux_dev = faux_device_create(name, NULL, NULL); + KUNIT_ASSERT_NOT_NULL(test, sched->faux_dev); + + args.dev = &sched->faux_dev->dev; + ret = drm_sched_init(&sched->base, &args); KUNIT_ASSERT_EQ(test, ret, 0); @@ -323,6 +336,7 @@ struct drm_mock_scheduler *drm_mock_sched_new(struct kunit *test, long timeout) void drm_mock_sched_fini(struct drm_mock_scheduler *sched) { drm_sched_fini(&sched->base); + faux_device_destroy(sched->faux_dev); } /** diff --git a/drivers/gpu/drm/scheduler/tests/sched_tests.h b/drivers/gpu/drm/scheduler/tests/sched_tests.h index 553d45abd057..bbf4da585866 100644 --- a/drivers/gpu/drm/scheduler/tests/sched_tests.h +++ b/drivers/gpu/drm/scheduler/tests/sched_tests.h @@ -7,6 +7,7 @@ #include <kunit/test.h> #include <linux/atomic.h> #include <linux/completion.h> +#include <linux/device/faux.h> #include <linux/dma-fence.h> #include <linux/hrtimer.h> #include <linux/ktime.h> @@ -44,6 +45,7 @@ struct drm_mock_scheduler { struct drm_gpu_scheduler base; struct kunit *test; + struct faux_device *faux_dev; spinlock_t lock; struct list_head job_list; -- 2.25.1 No virus found Checked by Hillstone Network AntiVirus
