[PATCH] drm/nouveau: Fixup gk20a instobj hierarchy

Jon Hunter jonathanh at nvidia.com
Thu Dec 14 09:25:00 UTC 2023



On 08/12/2023 10:46, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> Commit 12c9b05da918 ("drm/nouveau/imem: support allocations not
> preserved across suspend") uses container_of() to cast from struct
> nvkm_memory to struct nvkm_instobj, assuming that all instance objects
> are derived from struct nvkm_instobj. For the gk20a family that's not
> the case and they are derived from struct nvkm_memory instead. This
> causes some subtle data corruption (nvkm_instobj.preserve ends up
> mapping to gk20a_instobj.vaddr) that causes a NULL pointer dereference
> in gk20a_instobj_acquire_iommu() (and possibly elsewhere) and also
> prevents suspend/resume from working.
> 
> Fix this by making struct gk20a_instobj derive from struct nvkm_instobj
> instead.
> 
> Fixes: 12c9b05da918 ("drm/nouveau/imem: support allocations not preserved across suspend")
> Reported-by: Jonathan Hunter <jonathanh at nvidia.com>
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
> Note that this was probably subtly wrong before the above-mentioned
> commit already, but I don't think we've seen any reports that would
> indicate any actual failures related to this before. So I think it's
> good enough to apply this fix for v6.7. The next closest thing would
> be commit d8e83994aaf6 ("drm/nouveau/imem: improve management of
> instance memory"), but that's 8 years old (Linux v4.3)...
> ---
>   .../drm/nouveau/nvkm/subdev/instmem/gk20a.c    | 18 +++++++++---------
>   1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> index 1b811d6972a1..201022ae9214 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> @@ -49,14 +49,14 @@
>   #include <subdev/mmu.h>
>   
>   struct gk20a_instobj {
> -	struct nvkm_memory memory;
> +	struct nvkm_instobj base;
>   	struct nvkm_mm_node *mn;
>   	struct gk20a_instmem *imem;
>   
>   	/* CPU mapping */
>   	u32 *vaddr;
>   };
> -#define gk20a_instobj(p) container_of((p), struct gk20a_instobj, memory)
> +#define gk20a_instobj(p) container_of((p), struct gk20a_instobj, base.memory)
>   
>   /*
>    * Used for objects allocated using the DMA API
> @@ -148,7 +148,7 @@ gk20a_instobj_iommu_recycle_vaddr(struct gk20a_instobj_iommu *obj)
>   	list_del(&obj->vaddr_node);
>   	vunmap(obj->base.vaddr);
>   	obj->base.vaddr = NULL;
> -	imem->vaddr_use -= nvkm_memory_size(&obj->base.memory);
> +	imem->vaddr_use -= nvkm_memory_size(&obj->base.base.memory);
>   	nvkm_debug(&imem->base.subdev, "vaddr used: %x/%x\n", imem->vaddr_use,
>   		   imem->vaddr_max);
>   }
> @@ -283,7 +283,7 @@ gk20a_instobj_map(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *vmm,
>   {
>   	struct gk20a_instobj *node = gk20a_instobj(memory);
>   	struct nvkm_vmm_map map = {
> -		.memory = &node->memory,
> +		.memory = &node->base.memory,
>   		.offset = offset,
>   		.mem = node->mn,
>   	};
> @@ -391,8 +391,8 @@ gk20a_instobj_ctor_dma(struct gk20a_instmem *imem, u32 npages, u32 align,
>   		return -ENOMEM;
>   	*_node = &node->base;
>   
> -	nvkm_memory_ctor(&gk20a_instobj_func_dma, &node->base.memory);
> -	node->base.memory.ptrs = &gk20a_instobj_ptrs;
> +	nvkm_memory_ctor(&gk20a_instobj_func_dma, &node->base.base.memory);
> +	node->base.base.memory.ptrs = &gk20a_instobj_ptrs;
>   
>   	node->base.vaddr = dma_alloc_attrs(dev, npages << PAGE_SHIFT,
>   					   &node->handle, GFP_KERNEL,
> @@ -438,8 +438,8 @@ gk20a_instobj_ctor_iommu(struct gk20a_instmem *imem, u32 npages, u32 align,
>   	*_node = &node->base;
>   	node->dma_addrs = (void *)(node->pages + npages);
>   
> -	nvkm_memory_ctor(&gk20a_instobj_func_iommu, &node->base.memory);
> -	node->base.memory.ptrs = &gk20a_instobj_ptrs;
> +	nvkm_memory_ctor(&gk20a_instobj_func_iommu, &node->base.base.memory);
> +	node->base.base.memory.ptrs = &gk20a_instobj_ptrs;
>   
>   	/* Allocate backing memory */
>   	for (i = 0; i < npages; i++) {
> @@ -533,7 +533,7 @@ gk20a_instobj_new(struct nvkm_instmem *base, u32 size, u32 align, bool zero,
>   	else
>   		ret = gk20a_instobj_ctor_dma(imem, size >> PAGE_SHIFT,
>   					     align, &node);
> -	*pmemory = node ? &node->memory : NULL;
> +	*pmemory = node ? &node->base.memory : NULL;
>   	if (ret)
>   		return ret;
>   


Tested-by: Jon Hunter <jonathanh at nvidia.com>

Thanks!
Jon

-- 
nvpublic


More information about the dri-devel mailing list