dma-direct: reject highmem pages from dma_alloc_from_contiguous (704f2c20) · Commits · 戴 / test

dma_alloc_from_contiguous can return highmem pages depending on the setup, which a plain non-remapping DMA allocator can't handle. Detect this case and fail the allocation. Signed-off-by:

Christoph Hellwig <hch@lst.de> Reviewed-by:

Robin Murphy <robin.murphy@arm.com>

kernel/dma/direct.c

+12 −0

Original line number	Original line	Diff line number	Diff line
	@@ -162,6 +162,18 @@ void dma_direct_alloc_pages(struct device dev, size_t size,
	if (!page)		if (!page)
	return NULL;		return NULL;

			if (PageHighMem(page)) {
			/*
			* Depending on the cma= arguments and per-arch setup
			* dma_alloc_from_contiguous could return highmem pages.
			* Without remapping there is no way to return them here,
			* so log an error and fail.
			*/
			dev_info(dev, "Rejecting highmem page from CMA.\n");
			__dma_direct_free_pages(dev, size, page);
			return NULL;
			}

	ret = page_address(page);		ret = page_address(page);
	if (force_dma_unencrypted()) {		if (force_dma_unencrypted()) {
	set_memory_decrypted((unsigned long)ret, 1 << get_order(size));		set_memory_decrypted((unsigned long)ret, 1 << get_order(size));

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