From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:36785 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756685AbcAPAG0 (ORCPT ); Fri, 15 Jan 2016 19:06:26 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Mentz , Dan Williams , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 221/305] dma-debug: Fix dma_debug_entry offset calculation Date: Fri, 15 Jan 2016 16:00:35 -0800 Message-Id: <1452902519-2754-222-git-send-email-kamal@canonical.com> In-Reply-To: <1452902519-2754-1-git-send-email-kamal@canonical.com> References: <1452902519-2754-1-git-send-email-kamal@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: 4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Daniel Mentz commit 0354aec19ce3d355c6213b0434064efc25c9b22c upstream. dma-debug uses struct dma_debug_entry to keep track of dma coherent memory allocation requests. The virtual address is converted into a pfn and an offset. Previously, the offset was calculated using an incorrect bit mask. As a result, we saw incorrect error messages from dma-debug like the following: "DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000" Cacheline 0x03e00000 does not exist on our platform. Fixes: 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()") Signed-off-by: Daniel Mentz Signed-off-by: Dan Williams Signed-off-by: Kamal Mostafa --- lib/dma-debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index dace71f..c5fddeb 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1456,7 +1456,7 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size, entry->type = dma_debug_coherent; entry->dev = dev; entry->pfn = page_to_pfn(virt_to_page(virt)); - entry->offset = (size_t) virt & PAGE_MASK; + entry->offset = (size_t) virt & ~PAGE_MASK; entry->size = size; entry->dev_addr = dma_addr; entry->direction = DMA_BIDIRECTIONAL; @@ -1472,7 +1472,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size, .type = dma_debug_coherent, .dev = dev, .pfn = page_to_pfn(virt_to_page(virt)), - .offset = (size_t) virt & PAGE_MASK, + .offset = (size_t) virt & ~PAGE_MASK, .dev_addr = addr, .size = size, .direction = DMA_BIDIRECTIONAL, -- 1.9.1