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54 lines
2.1 KiB
Diff
54 lines
2.1 KiB
Diff
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From 6e2c437a2d0a85d90d3db85a7471f99764f7bbf8 Mon Sep 17 00:00:00 2001
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From: Marek Szyprowski <m.szyprowski@samsung.com>
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Date: Thu, 23 Apr 2015 12:46:16 +0100
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Subject: arm64: dma-mapping: always clear allocated buffers
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[ Upstream commit 6829e274a623187c24f7cfc0e3d35f25d087fcc5 ]
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Buffers allocated by dma_alloc_coherent() are always zeroed on Alpha,
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ARM (32bit), MIPS, PowerPC, x86/x86_64 and probably other architectures.
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It turned out that some drivers rely on this 'feature'. Allocated buffer
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might be also exposed to userspace with dma_mmap() call, so clearing it
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is desired from security point of view to avoid exposing random memory
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to userspace. This patch unifies dma_alloc_coherent() behavior on ARM64
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architecture with other implementations by unconditionally zeroing
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allocated buffer.
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CRs-Fixed: 1041735
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Change-Id: I74bf024e0f603ca8c0b05430dc2ee154d579cfb2
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Cc: <stable@vger.kernel.org> # v3.14+
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Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
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Signed-off-by: Will Deacon <will.deacon@arm.com>
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Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
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Git-commit: a142e9641dcbead2c8845c949ad518acac96ed28
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Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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[lmark@codeaurora.org: resolve merge conflicts]
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Signed-off-by: Liam Mark <lmark@codeaurora.org>
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---
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arch/arm64/mm/dma-mapping.c | 2 ++
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1 file changed, 2 insertions(+)
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diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
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index 9b4716e..2678f6e 100644
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--- a/arch/arm64/mm/dma-mapping.c
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+++ b/arch/arm64/mm/dma-mapping.c
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@@ -88,6 +88,7 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
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if (pageno < pool->nr_pages) {
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bitmap_set(pool->bitmap, pageno, count);
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ptr = pool->vaddr + PAGE_SIZE * pageno;
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+ memset(ptr, 0, size);
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*ret_page = pool->pages[pageno];
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} else {
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pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n"
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@@ -208,6 +209,7 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
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page = pfn_to_page(pfn);
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addr = page_address(page);
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+ memset(addr, 0, size);
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if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs) ||
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dma_get_attr(DMA_ATTR_STRONGLY_ORDERED, attrs)) {
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--
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cgit v1.1
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