From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA25FCA9EB9 for ; Tue, 22 Oct 2019 09:26:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 913B32064B for ; Tue, 22 Oct 2019 09:26:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="kGaNGEkG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731233AbfJVJ0c (ORCPT ); Tue, 22 Oct 2019 05:26:32 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:40654 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728182AbfJVJ0c (ORCPT ); Tue, 22 Oct 2019 05:26:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=TmHpYQq+1YByS74nVQpkYRgXw+YYJL9xlQu7xl3PVL8=; b=kGaNGEkGUIEjYOH8hF9k59Ymt 6wXz18tm9d79zRTmA5SM2IBIigAfi9rB45LZzWOk2a1tqSLib4ZVhza6RXpKqlzKvRFP/jIZkTsIS lLjPRtqv0KJBxDpJ6yHkbOdLky+U7dBrVODiTEjCKKxzBHMpz4UsvHNAnGAEX0e0XxFp7HeTDGsgs iv/5tHcL7GuQjJM4GdjCivABlirDMkjVbhduF2uQHhXSUoXrskLvSEFTeM2rYKHdXl2UYjRFWjk3G URk5ob7IMeqxCdPiepeudeJoHcXsJf5+hMJeboNZKpn9/eV7oxM3jdQzMTOwIZzP3sBa3fee6uw33 co42HPg1w==; Received: from shell.armlinux.org.uk ([2001:4d48:ad52:3201:5054:ff:fe00:4ec]:45900) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1iMqQn-0006GQ-9o; Tue, 22 Oct 2019 10:26:21 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1iMqQl-0004RU-83; Tue, 22 Oct 2019 10:26:19 +0100 Date: Tue, 22 Oct 2019 10:26:19 +0100 From: Russell King - ARM Linux admin To: Miquel Raynal Cc: Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Tudor Ambarus , Vignesh Raghavendra , stable@vger.kernel.org, Boris Brezillon , linux-mtd@lists.infradead.org, Thomas Petazzoni , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio Message-ID: <20191022092619.GQ25745@shell.armlinux.org.uk> References: <20191018143643.29676-1-miquel.raynal@bootlin.com> <20191022082643.GO25745@shell.armlinux.org.uk> <20191022111707.4b117b99@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191022111707.4b117b99@xps13> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Oct 22, 2019 at 11:17:07AM +0200, Miquel Raynal wrote: > Hi Russell, > > Russell King - ARM Linux admin wrote on Tue, 22 > Oct 2019 09:26:43 +0100: > > > On Fri, Oct 18, 2019 at 04:36:43PM +0200, Miquel Raynal wrote: > > > 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 > > > > I need the full oops if you want me to comment on this. > > FYI, I ran the dd command within a for loop, incrementing the block size > (bs) by one byte, if failed with bs=6. > > Disabling WB_MODE (burst mode) does not change anything. > > Adding a wmb() right after the memcpy_toio() prevents the fault. Thanks. Can you check what the result of the write buffer test earlier in the kernel boot is? CPU: Testing write buffer coherency: ... ? Thanks. > > Here is the full trace when writing 1001 bytes: > > # dd if=/dev/urandom bs=1001 count=1 of=/dev/mtd6 > Unhandled fault: external abort on non-linefetch (0x808) at 0xc90703e8 > pgd = c7be8000 > [c90703e8] *pgd=f8000452(bad) > Internal error: : 808 [#1] ARM > Modules linked in: > CPU: 0 PID: 660 Comm: dd Not tainted 4.14.0-00045-gf5d08192704f-dirty #6 > Hardware name: ST SPEAr600 (Flattened Device Tree) > task: c7a05080 task.stack: c7bd2000 > PC is at memcpy+0xcc/0x330 > LR is at 0x13f0ec28 > pc : [] lr : [<13f0ec28>] psr: 80000013 > sp : c7bd3e44 ip : 00000018 fp : 000003e9 > r10: 00000000 r9 : c7a9959c r8 : c7bd3eac > r7 : c7a99590 r6 : c7afb438 r5 : 00000300 r4 : 5171436c > r3 : 00000058 r2 : 80000000 r1 : c7be4be9 r0 : c90703e8 > Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > Control: 0005317f Table: 07be8000 DAC: 00000051 > Process dd (pid: 660, stack limit = 0xc7bd2190) > Stack: (0xc7bd3e44 to 0xc7bd4000) > 3e40: c9070300 000000e9 c0290d14 c9070300 c7be4b00 0001046f c9070000 > 3e60: c7afb418 00000000 c7bd3e98 000003e9 c7bd3f88 000003e9 00000000 000c0008 > 3e80: 00000051 c7bd2000 c7be4800 c028e57c 000003e9 c7bd3eac c7be4800 00000000 > 3ea0: c7bf73c0 c7addc00 000003e9 00000300 00000000 00000000 00000000 00000000 > 3ec0: 00000000 00000000 00000000 00000000 00000000 000003e9 c028e4bc c7962a80 > 3ee0: c7bd3f88 00000000 c7bd2000 00000000 000bf990 c00bdb0c 000bf990 c00bd878 > 3f00: 00000000 00000000 00000000 c7bd3f10 c7a688c0 c009eedc c7becb58 000c0000 > 3f20: 00000003 c7962460 c7962484 00000000 00000000 c045c2f8 00000003 c00d9e58 > 3f40: 000003e9 000c0008 c7962a80 c7bd3f88 00000000 c7bd2000 00000000 c00bddb4 > 3f60: 000bf990 c00bda6c 00000000 c7962a80 c7962a80 000c0008 000003e9 c000a804 > 3f80: c7bd2000 c00bdfa4 00000000 00000000 00000000 000bfd94 00000001 000c0008 > 3fa0: 00000004 c000a640 000bfd94 00000001 00000001 000c0008 000003e9 be8e8f53 > 3fc0: 000bfd94 00000001 000c0008 00000004 000c0008 000c0008 000003e9 000bf990 > 3fe0: 00000000 be8e8ba4 0000ea3c b6eba7ec 60000010 00000001 00000000 00000000 > [] (memcpy) from [] (spear_mtd_write+0x240/0x294) > [] (spear_mtd_write) from [] (mtdchar_write+0xc0/0x230) > [] (mtdchar_write) from [] (__vfs_write+0x1c/0x128) > [] (__vfs_write) from [] (vfs_write+0xa0/0x168) > [] (vfs_write) from [] (SyS_write+0x3c/0x90) > [] (SyS_write) from [] (ret_fast_syscall+0x0/0x44) > Code: e1b02f82 14d13001 24d14001 24d1c001 (14c03001) > ---[ end trace f9a736cc2841cf14 ]--- > Segmentation fault > > > Thanks, > Miquèl > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up