From 3eb61d7cb74cea2ea697363669fa256937164758 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Tue, 15 Jul 2025 10:26:22 +0200 Subject: Revert "drm/amdgpu: Use dma_buf from GEM object instance" This reverts commit 515986100d176663d0a03219a3056e4252f729e6. The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref. Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated. Hence, this revert to going back to using .import_attach->dmabuf. Signed-off-by: Thomas Zimmermann Reviewed-by: Simona Vetter Acked-by: Alex Deucher Link: https://lore.kernel.org/r/20250715082635.34974-1-tzimmermann@suse.de --- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c') diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c index ff98c87b2e0b..5743ebb2f1b7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c @@ -514,7 +514,7 @@ bool amdgpu_dmabuf_is_xgmi_accessible(struct amdgpu_device *adev, return false; if (drm_gem_is_imported(obj)) { - struct dma_buf *dma_buf = obj->dma_buf; + struct dma_buf *dma_buf = obj->import_attach->dmabuf; if (dma_buf->ops != &amdgpu_dmabuf_ops) /* No XGMI with non AMD GPUs */ -- cgit v1.2.3