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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 670E3C43461 for ; Wed, 21 Apr 2021 09:32:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3813C613E6 for ; Wed, 21 Apr 2021 09:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238275AbhDUJdH (ORCPT ); Wed, 21 Apr 2021 05:33:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237041AbhDUJdD (ORCPT ); Wed, 21 Apr 2021 05:33:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64077C06174A; Wed, 21 Apr 2021 02:32:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=YDpKhq3lEyHoaGRnqdn0n1KeXiDGOFgpAVazWEK6jjM=; b=hUTRioDO9yMCVjGjRtZdJIimKD amLrXljQUyiXujO/gW2E/5KfG3hGTS3/F4kpLS++BJSjrSaTN98spYobmufzP5bekJHiGjKwN9wqa P7Fwejqp6uAdUAsZYVsI+zikYWZ/+bI6vR1L1dIJCJXxMjmb8e1Fqatof//5WX0Uw365ZoCSPNpSj ha5Zl1BJwFTKzeO51GXyGmWZf9BTUbilsD+okvhfsT8MaGSdijhIZqLasYWnu0bIVq8lH/kNVKLQN kbIUYF4lSF/5gqsbfaya7Eyhy4yl3VNP21IzgC/PRgbYwcvcs9d19zs5Txx+IhHSMSVlal8LqhBw9 rOF3FDFQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lZ9Ay-00GKSu-6P; Wed, 21 Apr 2021 09:29:59 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 15616300130; Wed, 21 Apr 2021 11:29:38 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C529F20190AC3; Wed, 21 Apr 2021 11:29:38 +0200 (CEST) Date: Wed, 21 Apr 2021 11:29:38 +0200 From: Peter Zijlstra To: syzbot Cc: acme@kernel.org, acme@redhat.com, alexander.shishkin@linux.intel.com, andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, cobranza@ingcoecuador.com, daniel@iogearbox.net, eranian@google.com, john.fastabend@gmail.com, jolsa@redhat.com, kafai@fb.com, kpsingh@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, mingo@kernel.org, mingo@redhat.com, namhyung@kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, torvalds@linux-foundation.org, vincent.weaver@maine.edu, yhs@fb.com Subject: Re: [syzbot] INFO: task hung in perf_event_free_task Message-ID: References: <00000000000057102e058e722bba@google.com> <000000000000dfe1bc05c063d0fa@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000dfe1bc05c063d0fa@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 20, 2021 at 02:10:22AM -0700, syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 7af08140 Revert "gcov: clang: fix clang-11+ build" > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15416871d00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c0a6882014fd3d45 > dashboard link: https://syzkaller.appspot.com/bug?extid=7692cea7450c97fa2a0a > compiler: Debian clang version 11.0.1-2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=145c9ffed00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12de31ded00000 When I build that C file and run it, it completes. AFAICT that's not the expected outcome given we're looking for a hung-task scenario. Hmm?