Op 09-10-17 om 08:46 schreef Jeffy Chen:

Kmemleak reported memory leak after suspend and resume: unreferenced object 0xffffffc0e31d8880 (size 128): comm "bash", pid 181, jiffies 4294763583 (age 24.694s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 20 a2 eb c0 ff ff ff ......... ...... 01 00 00 00 00 00 00 00 80 87 1d e3 c0 ff ff ff ................ backtrace: [<ffffffc00034bb64>] __save_stack_trace+0x48/0x6c [<ffffffc00034c244>] create_object+0x138/0x254 [<ffffffc0009dd218>] kmemleak_alloc+0x58/0x8c [<ffffffc000346de4>] kmem_cache_alloc_trace+0x188/0x254 [<ffffffc0005af4c0>] drm_atomic_state_alloc+0x3c/0x88 [<ffffffc000591f0c>] drm_atomic_helper_duplicate_state+0x28/0x158 [<ffffffc000592098>] drm_atomic_helper_suspend+0x5c/0xf0

Problem here is that we are duplicating the drm_atomic_state in drm_atomic_helper_suspend(), but not unreference it in the resume path.

Fixes: 1494276000db ("drm/atomic-helper: Implement subsystem-level suspend/resume") Signed-off-by: Jeffy Chen jeffy.chen@rock-chips.com

---

Changes in v2: Unref duplicated drm_atomic_state in drm_atomic_helper_resume() instead of specific drivers.

drivers/gpu/drm/drm_atomic_helper.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 01c34bc5b5b0..4a262380c631 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -3052,6 +3052,7 @@ int drm_atomic_helper_resume(struct drm_device *dev, drm_modeset_backoff(&ctx); }

• drm_atomic_state_put(state); drm_modeset_drop_locks(&ctx); drm_modeset_acquire_fini(&ctx);

Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state") Cc: stable@vger.kernel.org # v4.10+

and pushed, thanks for finding it. :)

The bug is probably older than that commit, but only happened on failure paths before. If resume fails we probably have bigger issues than leaking some memory.