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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 C9DE9C43461 for ; Tue, 18 May 2021 10:40:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC18C611CC for ; Tue, 18 May 2021 10:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348585AbhERKmE (ORCPT ); Tue, 18 May 2021 06:42:04 -0400 Received: from foss.arm.com ([217.140.110.172]:48730 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242814AbhERKlz (ORCPT ); Tue, 18 May 2021 06:41:55 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D03F6106F; Tue, 18 May 2021 03:40:36 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.6.226]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CFFB53F719; Tue, 18 May 2021 03:40:32 -0700 (PDT) Date: Tue, 18 May 2021 11:40:29 +0100 From: Mark Rutland To: Peter Zijlstra Cc: syzbot , acme@kernel.org, alexander.shishkin@linux.intel.com, andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, jolsa@redhat.com, kafai@fb.com, kpsingh@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, namhyung@kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, yhs@fb.com Subject: Re: [syzbot] WARNING in __perf_install_in_context Message-ID: <20210518104029.GE82842@C02TD0UTHF1T.local> References: <000000000000b3d89a05c284718f@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, May 17, 2021 at 01:27:49PM +0200, Peter Zijlstra wrote: > On Mon, May 17, 2021 at 03:56:22AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 18a3c5f7 Merge tag 'for_linus' of git://git.kernel.org/pub.. > > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes > > console output: https://syzkaller.appspot.com/x/log.txt?x=1662c153d00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=b8ac1fe5995f69d7 > > dashboard link: https://syzkaller.appspot.com/bug?extid=0fb24f56fa707081e4f2 > > userspace arch: riscv64 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+0fb24f56fa707081e4f2@syzkaller.appspotmail.com > > > > ------------[ cut here ]------------ > > WARNING: CPU: 1 PID: 8643 at kernel/events/core.c:2781 __perf_install_in_context+0x1c0/0x47c kernel/events/core.c:2781 > > Modules linked in: > > CPU: 1 PID: 8643 Comm: syz-executor.0 Not tainted 5.12.0-rc8-syzkaller-00011-g18a3c5f7abfd #0 > > Hardware name: riscv-virtio,qemu (DT) > > How serious should I take this thing? ARM64 and x86_64 don't show these > errors. I think I've seen this in the past on arm64, but very rarely, and never with a consistent reproducer. I'm currently fuyzzing v5.13-rc1, and haven't hit anything like this after ~5 days. Thanks, Mark.