[Intel-gfx] [PATCH i-g-t] tests/drm_import_export: Always loop with mutex held

[Winiarski, Michal]

On Wed, 2015-11-25 at 15:20 +0200, Mika Kuoppala wrote:
> We assume that lock is held on start of the loop scope.
> Some paths continuing inside loop didn't adhere to this
> assumption, causing segfault on unlocking an already
> unlocked mutex. Fix this by re-aquiring lock always.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93013
> Cc: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Thomas Wood <thomas.wood at intel.com>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>

Reviewed-by: Michał Winiarski <michal.winiarski at intel.com>

> ---
>  tests/drm_import_export.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/tests/drm_import_export.c b/tests/drm_import_export.c
> index 49486ab..cfe5f6d 100644
> --- a/tests/drm_import_export.c
> +++ b/tests/drm_import_export.c
> @@ -161,20 +161,20 @@ static void *import_close_thread(void *data)
>  				pthread_mutex_unlock(&t->mutex);
>  			}
>  			else
> -				/* We take the lock right after
> entering the loop */
> +				/* Lock should be held on entering
> the loop */
>  				continue;
>  		}
> +
>  		if (bo == NULL) {
>  			/*
>  			 * If the bo is NULL it means that we've
> unreferenced in other
>  			 * thread - therefore we should expect
> ENOENT
>  			 */
>  			igt_assert_eq(errno, ENOENT);
> -			continue;
> +		} else {
> +			drm_intel_bo_unreference(bo);
>  		}
>  
> -		drm_intel_bo_unreference(bo);
> -
>  		pthread_mutex_lock(&t->mutex);
>  	}
>  	pthread_mutex_unlock(&t->mutex);