Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753472AbbBMSuS (ORCPT ); Fri, 13 Feb 2015 13:50:18 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:3420 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751839AbbBMSuQ (ORCPT ); Fri, 13 Feb 2015 13:50:16 -0500 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Fri, 13 Feb 2015 10:47:15 -0800 From: Alexandre Courbot To: Arnd Bergmann CC: Russell King , Marek Szyprowski , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, gnurou@gmail.com, Alexandre Courbot Subject: [PATCH RESEND v2] ARM: DMA: Fix kzalloc flags in __iommu_alloc_buffer() Date: Fri, 13 Feb 2015 15:35:55 +0900 Message-ID: <1423809355-9429-1-git-send-email-acourbot@nvidia.com> X-Mailer: git-send-email 2.3.0 X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1832 Lines: 53 From: Alexandre Courbot There doesn't seem to be any valid reason to allocate the pages array with the same flags as the buffer itself. Doing so can eventually lead to the following safeguard in mm/slab.c's cache_grow() to be hit: if (unlikely(flags & GFP_SLAB_BUG_MASK)) { pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); BUG(); } This happens when buffers are allocated with __GFP_DMA32 or __GFP_HIGHMEM. Fix this by allocating the pages array with GFP_KERNEL to follow what is done elsewhere in this file. Using GFP_KERNEL in __iommu_alloc_buffer() is safe because atomic allocations are handled by __iommu_alloc_atomic(). Signed-off-by: Alexandre Courbot Cc: Arnd Bergmann Cc: Marek Szyprowski Cc: Russell King Acked-by: Marek Szyprowski Acked-by: Will Deacon --- Changes since v1: - Updated commit message to better point the assert that fails - Added Will's ack arch/arm/mm/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 903dba064a03..170a116d1b29 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1106,7 +1106,7 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, int i = 0; if (array_size <= PAGE_SIZE) - pages = kzalloc(array_size, gfp); + pages = kzalloc(array_size, GFP_KERNEL); else pages = vzalloc(array_size); if (!pages) -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/