From patchwork Thu Nov 16 22:56:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miles Chen X-Patchwork-Id: 10062169 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EA07B6023A for ; Thu, 16 Nov 2017 22:56:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC17D2AC0A for ; Thu, 16 Nov 2017 22:56:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D07DE2AC40; Thu, 16 Nov 2017 22:56:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6E4B32AC0A for ; Thu, 16 Nov 2017 22:56:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=FVzbIuYrkxuz9USdpPt4CFv1qsDHmSieNoDJm8k13TU=; b=CpvNGkJZZqIHl/ e7ur+ZNaM29e63L/d5gc/Vv5ysHju9IjmshDzxJbUsSH9NI5Twc/20tbRcpvIRHjNkzwD5I0u064f 5Y+aUoz77gg/aXnDq3/5yUjfr0PnBNSoiY5950xvA6GIPdHGAx3ujJX4JWHTCYz4WzW3uHmq3SBKk H2K5NZUh2C6br4oJ8fue4jq1Un/Ry8+W+cClIKqyjkNEGVojcfZbG0r5qppyg+OqzbjdXEuf8YjPp damnsqOV1pYjIdYQwHO8KhggceuURZPHOYu1FqodqT5RDCQ7fvyMmYsJZFPx8iMSlU/n77fltV/iN q4eEnRBr05bggZWRO8DQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1eFT5V-0000a8-FP; Thu, 16 Nov 2017 22:56:49 +0000 Received: from [210.61.82.183] (helo=mailgw01.mediatek.com) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1eFT5S-0000Wg-LW for linux-mediatek@lists.infradead.org; Thu, 16 Nov 2017 22:56:48 +0000 X-UUID: 226678a9aa9b42fc80cf30fd672b7a21-20171117 Received: from mtkexhb02.mediatek.inc [(172.21.101.103)] by mailgw01.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 697916090; Fri, 17 Nov 2017 06:56:15 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs08n2.mediatek.inc (172.21.101.56) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Fri, 17 Nov 2017 06:56:13 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1210.3 via Frontend Transport; Fri, 17 Nov 2017 06:56:13 +0800 From: To: Christoph Hellwig , Robin Murphy , Andrew Morton Subject: [PATCH v4] dma-debug: fix incorrect pfn calculation Date: Fri, 17 Nov 2017 06:56:12 +0800 Message-ID: <1510872972-23919-1-git-send-email-miles.chen@mediatek.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171116_145646_850979_AAD53083 X-CRM114-Status: UNSURE ( 9.74 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Miles Chen , wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Miles Chen dma-debug reports the following warning: [name:panic&]WARNING: CPU: 3 PID: 298 at kernel-4.4/lib/dma-debug.c:604 debug _dma_assert_idle+0x1a8/0x230() DMA-API: cpu touching an active dma mapped cacheline [cln=0x00000882300] CPU: 3 PID: 298 Comm: vold Tainted: G W O 4.4.22+ #1 Hardware name: MT6739 (DT) Call trace: [] dump_backtrace+0x0/0x1d4 [] show_stack+0x14/0x1c [] dump_stack+0xa8/0xe0 [] warn_slowpath_common+0xf4/0x11c [] warn_slowpath_fmt+0x60/0x80 [] debug_dma_assert_idle+0x1a8/0x230 [] wp_page_copy.isra.96+0x118/0x520 [] do_wp_page+0x4fc/0x534 [] handle_mm_fault+0xd4c/0x1310 [] do_page_fault+0x1c8/0x394 [] do_mem_abort+0x50/0xec I found that debug_dma_alloc_coherent() and debug_dma_free_coherent() assume that dma_alloc_coherent() always returns a linear address. However it's possible that dma_alloc_coherent() returns a non-linear address. In this case, page_to_pfn(virt_to_page(virt)) will return an incorrect pfn. If the pfn is valid and mapped as a COW page, we will hit the warning when doing wp_page_copy(). Fix this by calculating pfn for linear and non-linear addresses. Signed-off-by: Miles Chen --- lib/dma-debug.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index ea4cc3d..1b34d21 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1495,14 +1495,22 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size, if (!entry) return; + /* handle vmalloc and linear addresses */ + if (!is_vmalloc_addr(virt) && !virt_to_page(virt)) + return; + entry->type = dma_debug_coherent; entry->dev = dev; - entry->pfn = page_to_pfn(virt_to_page(virt)); entry->offset = offset_in_page(virt); entry->size = size; entry->dev_addr = dma_addr; entry->direction = DMA_BIDIRECTIONAL; + if (is_vmalloc_addr(virt)) + entry->pfn = vmalloc_to_pfn(virt); + else + entry->pfn = page_to_pfn(virt_to_page(virt)); + add_dma_entry(entry); } EXPORT_SYMBOL(debug_dma_alloc_coherent); @@ -1513,13 +1521,21 @@ void debug_dma_free_coherent(struct device *dev, size_t size, struct dma_debug_entry ref = { .type = dma_debug_coherent, .dev = dev, - .pfn = page_to_pfn(virt_to_page(virt)), .offset = offset_in_page(virt), .dev_addr = addr, .size = size, .direction = DMA_BIDIRECTIONAL, }; + /* handle vmalloc and linear addresses */ + if (!is_vmalloc_addr(virt) && !virt_to_page(virt)) + return; + + if (is_vmalloc_addr(virt)) + ref.pfn = vmalloc_to_pfn(virt); + else + ref.pfn = page_to_pfn(virt_to_page(virt)); + if (unlikely(dma_debug_disabled())) return;