On 3/6/24 06:01, 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().
Finally, as there is no need to have physically contiguous memory,
this patch switches kcalloc() to kvcalloc() in order to avoid
failing allocations.
Fixes: 249881232e14 ("nouveau/dmem: evict device private memory during release")
Suggested-by: Danilo Krummrich <dakr@xxxxxxxxxx>
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
Applied to drm-misc-fixes, thanks!
--- Changes in v3: - Switch kcalloc() to kvcalloc(). drivers/gpu/drm/nouveau/nouveau_dmem.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 12feecf71e7..6fb65b01d77 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 = kvcalloc(npages, sizeof(*src_pfns), GFP_KERNEL | __GFP_NOFAIL); + dst_pfns = kvcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL | __GFP_NOFAIL); + dma_addrs = kvcalloc(npages, sizeof(*dma_addrs), GFP_KERNEL | __GFP_NOFAIL);migrate_device_range(src_pfns, chunk->pagemap.range.start >> PAGE_SHIFT,npages); @@ -406,11 +406,11 @@ nouveau_dmem_evict_chunk(struct nouveau_dmem_chunk *chunk) migrate_device_pages(src_pfns, dst_pfns, npages); nouveau_dmem_fence_done(&fence); migrate_device_finalize(src_pfns, dst_pfns, npages); - kfree(src_pfns); - kfree(dst_pfns); + kvfree(src_pfns); + kvfree(dst_pfns); for (i = 0; i < npages; i++) dma_unmap_page(chunk->drm->dev->dev, dma_addrs[i], PAGE_SIZE, DMA_BIDIRECTIONAL); - kfree(dma_addrs); + kvfree(dma_addrs); }void
