diff options
| author | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2023-03-07 15:46:15 +0100 |
|---|---|---|
| committer | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2023-03-07 18:26:38 +0100 |
| commit | 9a9a8fe26751334b7739193a94eba741073b8a55 (patch) | |
| tree | a11152e5e156ba71a50c9614f6311260267f2d09 /drivers/gpu/drm/ttm | |
| parent | c22f2ff8724b49dce2ae797e9fbf4bc0fa91112f (diff) | |
drm/ttm: Fix a NULL pointer dereference
The LRU mechanism may look up a resource in the process of being removed
from an object. The locking rules here are a bit unclear but it looks
currently like res->bo assignment is protected by the LRU lock, whereas
bo->resource is protected by the object lock, while *clearing* of
bo->resource is also protected by the LRU lock. This means that if
we check that bo->resource points to the LRU resource under the LRU
lock we should be safe.
So perform that check before deciding to swap out a bo. That avoids
dereferencing a NULL bo->resource in ttm_bo_swapout().
Fixes: 6a9b02899402 ("drm/ttm: move the LRU into resource handling v4")
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Philip Yang <Philip.Yang@amd.com>
Cc: Qiang Yu <qiang.yu@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.19+
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230307144621.10748-2-thomas.hellstrom@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/ttm')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_device.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index e7147e304637..b84f74807ca1 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -158,7 +158,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo = res->bo; uint32_t num_pages; - if (!bo) + if (!bo || bo->resource != res) continue; num_pages = PFN_UP(bo->base.size); |