diff mbox series

[3/8] dma-direct check for highmem pages in dma_direct_alloc_pages

Message ID 20200930160917.1234225-4-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [1/8] dma-mapping: remove the {alloc,free}_noncoherent methods | expand

Commit Message

Christoph Hellwig Sept. 30, 2020, 4:09 p.m. UTC 
Check for highmem pages from CMA, just like in the dma_direct_alloc path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/dma/direct.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 121a9c1969dd3a..b5f20781d3a96f 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -309,6 +309,17 @@  struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
 	page = __dma_direct_alloc_pages(dev, size, gfp);
 	if (!page)
 		return NULL;
+	if (PageHighMem(page)) {
+		/*
+		 * Depending on the cma= arguments and per-arch setup
+		 * dma_alloc_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");
+		goto out_free_pages;
+	}
+
 	ret = page_address(page);
 	if (force_dma_unencrypted(dev)) {
 		if (set_memory_decrypted((unsigned long)ret,