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 50CC8C433DF for ; Thu, 11 Jun 2020 19:25:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2230C206C3 for ; Thu, 11 Jun 2020 19:25:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="QIDHeZQ/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726285AbgFKTZl (ORCPT ); Thu, 11 Jun 2020 15:25:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725869AbgFKTZl (ORCPT ); Thu, 11 Jun 2020 15:25:41 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41C80C08C5C1 for ; Thu, 11 Jun 2020 12:25:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=koVl8W/ZBRTJJgK/g8lrQxTLHfCfIJ27kfDv+tOpgVE=; b=QIDHeZQ/xKqc7U9s+vRcXVNU5a 7fh0qcCT/L7twhTGgMVTgMbuHY0ZM66gT7q9swOjm9KEOdxozG2uKPk1tsUoIin8vU2jTIi/wBDhd lxmFPYE+4vCiU0Prcmjpxfu5hxHkiFItYwJBSJ2U1baBGx58os/s2qy0bCRiDiDxHb/cNUdwXIMr6 HfESkbm3A8KrdUouXGXnhmP6aGk9bkxp5LzmcIqdnN/xhxnVZ2dz/s+hep8v0alTV/TLVDsQuJUhI PXgpb6Q0UHti89OD2+dnAvHYMXYm/kavAaySc4F6sZ802Akfd78qyWRoNoC3CPCpR8LAYt3DtWyEf t3qdaKTw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjSpF-0003sg-FW; Thu, 11 Jun 2020 19:25:21 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 54FA89841E9; Thu, 11 Jun 2020 21:25:18 +0200 (CEST) Date: Thu, 11 Jun 2020 21:25:18 +0200 From: Peter Zijlstra To: Andy Lutomirski Cc: Naresh Kamboju , open list , X86 ML , cj.chengjian@huawei.com, Arnaldo Carvalho de Melo , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Thomas Gleixner , Minchan Kim , Andrew Morton , Michel Lespinasse , lkft-triage@lists.linaro.org, Dave Hansen Subject: Re: Perf: WARNING: arch/x86/entry/common.c:624 idtentry_exit_cond_rcu+0x92/0xc0 Message-ID: <20200611192518.GA2483@worktop.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 11, 2020 at 12:10:50PM -0700, Andy Lutomirski wrote: > On Thu, Jun 11, 2020 at 11:56 AM Naresh Kamboju > wrote: > > > > While running perf test and selftest x86 single_step_syscall_32 on > > i386 kernel linux > > next 5.7.0-next-20200610 kernel warning noticed. > > > > steps to reproduce: > > -------------------------- > > perf test > > and > > cd /opt/kselftests/default-in-kernel/x86 > > ./single_step_syscall_32 > > > > perf warning log: > > ---------------------- > > [ 57.260865] ------------[ cut here ]------------ > > [ 57.266576] IRQs not disabled as expected > > [ 57.270583] WARNING: CPU: 1 PID: 500 at > > /usr/src/kernel/arch/x86/entry/common.c:624 > > idtentry_exit_cond_rcu+0x92/0xc0 > > [ 57.281092] Modules linked in: x86_pkg_temp_thermal fuse > > [ 57.286406] CPU: 1 PID: 500 Comm: perf Not tainted 5.7.0-next-20200610 #1 > > [ 57.293190] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS > > 2.2 05/23/2018 > > [ 57.300577] EIP: idtentry_exit_cond_rcu+0x92/0xc0 > > [ 57.305280] Code: 8b 89 d8 05 00 00 85 c9 74 ae 80 3d b1 64 2c d4 > > 00 75 a5 68 94 2d fb d3 89 55 f8 89 45 fc c6 05 b1 64 2c d4 01 e8 8e > > f5 2b ff <0f> 0b 58 8b 55 f8 8b 45 fc eb 83 8d 76 00 e8 5b fd ff ff c9 > > c3 89 > > [ 57.324017] EAX: 0000001d EBX: 0d00022a ECX: 00000027 EDX: f5b9e14c > > [ 57.330274] ESI: f2a2ffb4 EDI: ffff0ff4 EBP: f2a2ff8c ESP: f2a2ff80 > > [ 57.336531] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010096 > > [ 57.343345] CR0: 80050033 CR2: 08700a58 CR3: 14ad7000 CR4: 003406d0 > > [ 57.349608] DR0: 080dfb80 DR1: 080dfc00 DR2: 08700a58 DR3: 00000000 > > [ 57.355866] DR6: fffe0ff0 DR7: 0d00062a > > [ 57.359697] Call Trace: > > [ 57.362143] exc_debug+0x84/0x1b0 > > [ 57.365487] ? exc_int3+0x1d0/0x1d0 > > [ 57.368981] handle_exception+0x145/0x145 > > [ 57.372991] EIP: 0x80dfbcd > > [ 57.375694] Code: Bad RIP value. > > [ 57.378918] EAX: 00000000 EBX: 00000005 ECX: 00002400 EDX: 00000000 > > [ 57.385175] ESI: 00000003 EDI: 00000004 EBP: bfd59798 ESP: bfd59770 > > [ 57.391431] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000246 > > [ 57.398215] irq event stamp: 1896 > > A regrettable property of the current entry code structure is that we > lose any real indication of the vector. Presumably this is #DB, hence > exc_debug. I don't know what perf has to do with it. > > I'll bang on this after lunch if no one beats me to it. Puzzling, CR3 seems to suggest this is !user_mode(), but either way #DB has either idtentry_enter_user() or nmi_enter().