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

[Thomas Hellström (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: stable@xxxxxxxxxxxxxxx

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.hellstrom@xxxxxxxxxxxxxxx>


> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> ---
>   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;
>   		}
>   	}