Hi Duoming,
thanks for sending a V2.
On 3/5/24 15:39, Duoming Zhou wrote:
The kcalloc() in nouveau_dmem_evict_chunk() will return null if
the physical memory has run out. As a result, if we dereference
src_pfns, dst_pfns or dma_addrs, the null pointer dereference bugs
will happen.
Moreover, the GPU is going away. If the kcalloc() fails, we could not
evict all pages mapping a chunk. So this patch adds a __GFP_NOFAIL
flag in kcalloc().
Fixes: 249881232e14 ("nouveau/dmem: evict device private memory during release")
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
---
Changes in v2:
- Allocate with __GFP_NOFAIL.
drivers/gpu/drm/nouveau/nouveau_dmem.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 12feecf71e7..f5ae9724ee2 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -378,9 +378,9 @@ nouveau_dmem_evict_chunk(struct nouveau_dmem_chunk *chunk)
dma_addr_t *dma_addrs;
struct nouveau_fence *fence;
- src_pfns = kcalloc(npages, sizeof(*src_pfns), GFP_KERNEL);
- dst_pfns = kcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL);
- dma_addrs = kcalloc(npages, sizeof(*dma_addrs), GFP_KERNEL);
+ src_pfns = kcalloc(npages, sizeof(*src_pfns), GFP_KERNEL | __GFP_NOFAIL);
+ dst_pfns = kcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL | __GFP_NOFAIL);
+ dma_addrs = kcalloc(npages, sizeof(*dma_addrs), GFP_KERNEL | __GFP_NOFAIL);
I think we should also switch to kvcalloc(), AFAICS we don't need
physically contiguous memory.
Sorry I did not mention that in V1 already.
- Danilo
migrate_device_range(src_pfns, chunk->pagemap.range.start >> PAGE_SHIFT,
npages);
