From patchwork Fri Oct 18 14:36:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 11198595 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B1664112C for ; Fri, 18 Oct 2019 14:36:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8F710222BD for ; Fri, 18 Oct 2019 14:36:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FCZnRllL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F710222BD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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=xK+ZjkEzV9WcqN2lthjCUJ8SWsK2OdF3hYJY0jQ2a9M=; b=FCZnRllLsqXKGA NGKYbzZDbEvJQ/gNCxkaDeI/4N/kTMJ2+fVeWSEWCsJR/6/oPAxfE3m/6RI3/zQ5UaYYqAM18Tg3C UuRk5ONAXSho4PttJiRpQUHQzJY82MG2F8PWzO4UUQVUP/OThqIb3GejkmLNrxXH0rxW/G+Mmf9vm WYMQ9pdmA6MFIMEF+YS29IzMVR+69UYH5T0znl93WXsplQ+jDQVJumx1vKAhIwaVZDMtQTnjeUAlY tj01YHAM4rO2eGwOwEhMpmG3HxDDR4Ta0RTWxgwcPRCOrDRcUJ8/rKXfbweNitk7Hp10gPrp5mHkr +oPEPxMdJGq+ISkC4/fg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLTN7-0006FQ-3T; Fri, 18 Oct 2019 14:36:53 +0000 Received: from relay4-d.mail.gandi.net ([217.70.183.196]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLTN3-0006EI-SK; Fri, 18 Oct 2019 14:36:51 +0000 X-Originating-IP: 86.250.200.211 Received: from localhost.localdomain (lfbn-1-17395-211.w86-250.abo.wanadoo.fr [86.250.200.211]) (Authenticated sender: miquel.raynal@bootlin.com) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 31813E0014; Fri, 18 Oct 2019 14:36:45 +0000 (UTC) From: Miquel Raynal To: Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Tudor Ambarus , Vignesh Raghavendra Subject: [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio Date: Fri, 18 Oct 2019 16:36:43 +0200 Message-Id: <20191018143643.29676-1-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191018_073650_046786_EB784C6A X-CRM114-Status: GOOD ( 15.11 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.183.196 listed in list.dnswl.org] 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [217.70.183.196 listed in wl.mailspike.net] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable@vger.kernel.org, Boris Brezillon , linux-mtd@lists.infradead.org, Thomas Petazzoni , Miquel Raynal , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Any write with either dd or flashcp to a device driven by the spear_smi.c driver will pass through the spear_smi_cpy_toio() function. This function will get called for chunks of up to 256 bytes. If the amount of data is smaller, we may have a problem if the data length is not 4-byte aligned. In this situation, the kernel panics during the memcpy: # dd if=/dev/urandom bs=1001 count=1 of=/dev/mtd6 spear_smi_cpy_toio [620] dest c9070000, src c7be8800, len 256 spear_smi_cpy_toio [620] dest c9070100, src c7be8900, len 256 spear_smi_cpy_toio [620] dest c9070200, src c7be8a00, len 256 spear_smi_cpy_toio [620] dest c9070300, src c7be8b00, len 233 Unhandled fault: external abort on non-linefetch (0x808) at 0xc90703e8 [...] PC is at memcpy+0xcc/0x330 Workaround this issue by using the alternate _memcpy_toio() method which at least does not present the same problem. Fixes: f18dbbb1bfe0 ("mtd: ST SPEAr: Add SMI driver for serial NOR flash") Cc: stable@vger.kernel.org Suggested-by: Boris Brezillon Signed-off-by: Miquel Raynal --- Hello, This patch could not be tested with a mainline kernel (only compiled) but was tested with a stable 4.14.x kernel. I have really no idea why memcpy fails in this situation that's why I propose this workaround but I bet there is something deeper not working. Thanks, Miquèl drivers/mtd/devices/spear_smi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/devices/spear_smi.c b/drivers/mtd/devices/spear_smi.c index 986f81d2f93e..d888625a3244 100644 --- a/drivers/mtd/devices/spear_smi.c +++ b/drivers/mtd/devices/spear_smi.c @@ -614,7 +614,7 @@ static inline int spear_smi_cpy_toio(struct spear_smi *dev, u32 bank, ctrlreg1 = readl(dev->io_base + SMI_CR1); writel((ctrlreg1 | WB_MODE) & ~SW_MODE, dev->io_base + SMI_CR1); - memcpy_toio(dest, src, len); + _memcpy_toio(dest, src, len); writel(ctrlreg1, dev->io_base + SMI_CR1);