Re: [PATCH v6 01/22] drm/gem: Properly annotate WW context on drm_gem_lock_reservations() error

[Intel]

Hi,

On 5/27/22 01:50, 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 needs to be annotated
as "freed"

s /WW/ww_acquire_context/ ?
s /"freed"/"released"/ ?


, which fixes the noisy "WARNING: held lock freed!" splat
of VirtIO-GPU driver with CONFIG_DEBUG_MUTEXES=y and enabled lockdep.

Cc: sta...@vger.kernel.org

Can you dig up the commit in error and add a Fixes: Tag?

Using that and "dim fixes" will also make the Cc: stable tag a bit more 
verbose.

With that fixed,

Reviewed-by: Thomas Hellström <thomas.hellst...@linux.intel.com>


Signed-off-by: Dmitry Osipenko <dmitry.osipe...@collabora.com>
---
  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;
                }
        }