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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 A047EC67839 for ; Wed, 12 Dec 2018 00:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43A432084E for ; Wed, 12 Dec 2018 00:24:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43A432084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726242AbeLLAYB (ORCPT ); Tue, 11 Dec 2018 19:24:01 -0500 Received: from ozlabs.org ([203.11.71.1]:43453 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726183AbeLLAYA (ORCPT ); Tue, 11 Dec 2018 19:24:00 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43DyGk3tn1z9s3l; Wed, 12 Dec 2018 11:23:58 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v3] powerpc: implement CONFIG_DEBUG_VIRTUAL In-Reply-To: References: Date: Wed, 12 Dec 2018 11:23:58 +1100 Message-ID: <87va3zwq1t.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy writes: > This patch implements CONFIG_DEBUG_VIRTUAL to warn about > incorrect use of virt_to_phys() and page_to_phys() > > Below is the result of test_debug_virtual: > > [ 1.438746] WARNING: CPU: 0 PID: 1 at ./arch/powerpc/include/asm/io.h:808 test_debug_virtual_init+0x3c/0xd4 > [ 1.448156] CPU: 0 PID: 1 Comm: swapper Not tainted 4.20.0-rc5-00560-g6bfb52e23a00-dirty #532 > [ 1.457259] NIP: c066c550 LR: c0650ccc CTR: c066c514 > [ 1.462257] REGS: c900bdb0 TRAP: 0700 Not tainted (4.20.0-rc5-00560-g6bfb52e23a00-dirty) > [ 1.471184] MSR: 00029032 CR: 48000422 XER: 20000000 > [ 1.477811] > [ 1.477811] GPR00: c0650ccc c900be60 c60d0000 00000000 006000c0 c9000000 00009032 c7fa0020 > [ 1.477811] GPR08: 00002400 00000001 09000000 00000000 c07b5d04 00000000 c00037d8 00000000 > [ 1.477811] GPR16: 00000000 00000000 00000000 00000000 c0760000 c0740000 00000092 c0685bb0 > [ 1.477811] GPR24: c065042c c068a734 c0685b8c 00000006 00000000 c0760000 c075c3c0 ffffffff > [ 1.512711] NIP [c066c550] test_debug_virtual_init+0x3c/0xd4 > [ 1.518315] LR [c0650ccc] do_one_initcall+0x8c/0x1cc > [ 1.523163] Call Trace: > [ 1.525595] [c900be60] [c0567340] 0xc0567340 (unreliable) > [ 1.530954] [c900be90] [c0650ccc] do_one_initcall+0x8c/0x1cc > [ 1.536551] [c900bef0] [c0651000] kernel_init_freeable+0x1f4/0x2cc > [ 1.542658] [c900bf30] [c00037ec] kernel_init+0x14/0x110 > [ 1.547913] [c900bf40] [c000e1d0] ret_from_kernel_thread+0x14/0x1c > [ 1.553971] Instruction dump: > [ 1.556909] 3ca50100 bfa10024 54a5000e 3fa0c076 7c0802a6 3d454000 813dc204 554893be > [ 1.564566] 7d294010 7d294910 90010034 39290001 <0f090000> 7c3e0b78 955e0008 3fe0c062 > [ 1.572425] ---[ end trace 6f6984225b280ad6 ]--- > [ 1.577467] PA: 0x09000000 for VA: 0xc9000000 > [ 1.581799] PA: 0x061e8f50 for VA: 0xc61e8f50 > > Signed-off-by: Christophe Leroy > --- > v3: Added missing linux/mm.h > I realised that a driver may use DMA on stack after checking with virt_addr_valid(), so the new > verification might induce false positives. I remove it for now, will add it again later in a more > controled way. What is this comment referring to? I can't see any difference to v2 except the linux/mm.h include. cheers