From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out4-smtp.messagingengine.com ([66.111.4.28]:39458 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750994AbbEIRNP (ORCPT ); Sat, 9 May 2015 13:13:15 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id 8A4BF207F6 for ; Sat, 9 May 2015 13:13:14 -0400 (EDT) Subject: FAILED: patch "[PATCH] arm64: dma-mapping: always clear allocated buffers" failed to apply to 3.14-stable tree To: m.szyprowski@samsung.com, stable@vger.kernel.org, will.deacon@arm.com Cc: From: Date: Sat, 09 May 2015 19:12:49 +0200 Message-ID: <1431191569244180@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 3.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From 6829e274a623187c24f7cfc0e3d35f25d087fcc5 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Thu, 23 Apr 2015 12:46:16 +0100 Subject: [PATCH] arm64: dma-mapping: always clear allocated buffers Buffers allocated by dma_alloc_coherent() are always zeroed on Alpha, ARM (32bit), MIPS, PowerPC, x86/x86_64 and probably other architectures. It turned out that some drivers rely on this 'feature'. Allocated buffer might be also exposed to userspace with dma_mmap() call, so clearing it is desired from security point of view to avoid exposing random memory to userspace. This patch unifies dma_alloc_coherent() behavior on ARM64 architecture with other implementations by unconditionally zeroing allocated buffer. Cc: # v3.14+ Signed-off-by: Marek Szyprowski Signed-off-by: Will Deacon diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index ef7d112f5ce0..e0f14ee26b68 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -67,8 +67,7 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) *ret_page = phys_to_page(phys); ptr = (void *)val; - if (flags & __GFP_ZERO) - memset(ptr, 0, size); + memset(ptr, 0, size); } return ptr; @@ -113,8 +112,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, *dma_handle = phys_to_dma(dev, page_to_phys(page)); addr = page_address(page); - if (flags & __GFP_ZERO) - memset(addr, 0, size); + memset(addr, 0, size); return addr; } else { return swiotlb_alloc_coherent(dev, size, dma_handle, flags);