[PATCH 5.18 0075/1095] drm/gem: Properly annotate WW context on drm_gem_lock_reservations() error

Greg Kroah-Hartman
2022-08-15T20:17:36Z

From: Dmitry Osipenko <dmitry.osipenko@collabora.com>

commit 2939deac1fa220bc82b89235f146df1d9b52e876 upstream.

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>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220630200405.1883897-2-dmitry.osipenko@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/drm_gem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1225,7 +1225,7 @@ retry:
ret = dma_resv_lock_slow_interruptible(obj->resv,
acquire_ctx);
if (ret) {
- ww_acquire_done(acquire_ctx);
+ ww_acquire_fini(acquire_ctx);
return ret;
}
}
@@ -1250,7 +1250,7 @@ retry:
goto retry;
}

- ww_acquire_done(acquire_ctx);
+ ww_acquire_fini(acquire_ctx);
return ret;
}
}