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| author |   Christoph Hellwig <hch@lst.de> | 2018-09-22 20:47:26 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2018-12-01 17:56:08 +0100 |
| commit | 704f2c20eaa566f6906e8812b6e2115889bd753d (patch) | |
| tree | 034ad1e559756ddeb333662819a4439a6f817196 /kernel/dma | |
| parent | dma-direct: provide page based alloc/free helpers (diff) | |
| download | linux-dev-704f2c20eaa566f6906e8812b6e2115889bd753d.tar.xz linux-dev-704f2c20eaa566f6906e8812b6e2115889bd753d.zip | |
dma-direct: reject highmem pages from dma_alloc_from_contiguous
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>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 680287779b0a..c49849bcced6 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -162,6 +162,18 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, if (!page) 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); if (force_dma_unencrypted()) { set_memory_decrypted((unsigned long)ret, 1 << get_order(size)); |