Re: [PATCH v7 1/2] drm/gem: Properly annotate WW context on drm_gem_lock_reservations() error
From: Daniel Vetter <hidden>
Date: 2022-08-09 16:41:20
Also in:
dri-devel, linux-tegra, lkml
On Thu, Jun 30, 2022 at 11:04:04PM +0300, Dmitry Osipenko wrote:
Use ww_acquire_fini() in the error code paths. Otherwise lockdep
thinks that lock is held when lock's memory is freed after the
drm_gem_lock_reservations() error. The ww_acquire_context needs to be
annotated as "released", which fixes the noisy "WARNING: held lock freed!"
splat of VirtIO-GPU driver with CONFIG_DEBUG_MUTEXES=y and enabled lockdep.
Cc: stable@vger.kernel.org
Fixes: 7edc3e3b975b5 ("drm: Add helpers for locking an array of BO reservations.")
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>I merged this one to drm-misc-next-fixes. The other one looks like there's still opens pending, pls resubmit appropriately (and maybe with some analysis in the commit message of how exactly this impacts other drivers). -Daniel
quoted hunk
--- drivers/gpu/drm/drm_gem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index eb0c2d041f13..86d670c71286 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c@@ -1226,7 +1226,7 @@ drm_gem_lock_reservations(struct drm_gem_object **objs, int count, ret = dma_resv_lock_slow_interruptible(obj->resv, acquire_ctx); if (ret) { - ww_acquire_done(acquire_ctx); + ww_acquire_fini(acquire_ctx); return ret; } }@@ -1251,7 +1251,7 @@ drm_gem_lock_reservations(struct drm_gem_object **objs, int count, goto retry; } - ww_acquire_done(acquire_ctx); + ww_acquire_fini(acquire_ctx); return ret; } }-- 2.36.1
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization