From 60e536b0a564eabaeae5fb3ac2f806df95134e78 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Fri, 15 Jul 2022 09:57:22 +0200 Subject: [PATCH] drm/ttm: fix locking in vmap/vunmap TTM GEM helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit dbd0da2453c694f2f74651834d90fb280b57f151 upstream. I've stumbled over this while reviewing patches for DMA-buf and it looks like we completely messed the locking up here. In general most TTM function should only be called while holding the appropriate BO resv lock. Without this we could break the internal buffer object state here. Only compile tested! Signed-off-by: Christian König Fixes: 43676605f890 ("drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/20220715111533.467012-1-christian.koenig@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_gem_ttm_helper.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c index ecf3d2a54a98..759c65bfd284 100644 --- a/drivers/gpu/drm/drm_gem_ttm_helper.c +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c @@ -64,8 +64,13 @@ int drm_gem_ttm_vmap(struct drm_gem_object *gem, struct dma_buf_map *map) { struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); + int ret; - return ttm_bo_vmap(bo, map); + dma_resv_lock(gem->resv, NULL); + ret = ttm_bo_vmap(bo, map); + dma_resv_unlock(gem->resv); + + return ret; } EXPORT_SYMBOL(drm_gem_ttm_vmap); @@ -82,7 +87,9 @@ void drm_gem_ttm_vunmap(struct drm_gem_object *gem, { struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); + dma_resv_lock(gem->resv, NULL); ttm_bo_vunmap(bo, map); + dma_resv_unlock(gem->resv); } EXPORT_SYMBOL(drm_gem_ttm_vunmap);