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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83F3CC004C0 for ; Mon, 23 Oct 2023 14:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232316AbjJWO6H (ORCPT ); Mon, 23 Oct 2023 10:58:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233807AbjJWOow (ORCPT ); Mon, 23 Oct 2023 10:44:52 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49717269D; Mon, 23 Oct 2023 07:43:33 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 731642188D; Mon, 23 Oct 2023 14:43:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1698072211; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3mWnimA+rB45DdXIO//K0LJL74BS6+rPPoMNkuJC8w4=; b=C6qrs4g0jsDTg/6TjxWrP2fI0tkZUezsEVX5EraDP83B9ZInndNT3opR3YA/aF4lTpEF6N aGY2OpJHJMZmRIZqm1tdh1N+DEk53L7NbXtq5gbPrRMEfDKLYg2euxd8RXJ/Dyn8OFmrMF q5cV+n9DAXfJ455zH4C3YdIs/XEXqkY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1698072211; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3mWnimA+rB45DdXIO//K0LJL74BS6+rPPoMNkuJC8w4=; b=IVdZCgiSzyXjHkb8KY2QiZabkPJ/NYpnPHJVjtkdaw5LEgBoTmgi3WGlOittza//ekkulb CrAHXdpfja+VplDA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3E00A139C2; Mon, 23 Oct 2023 14:43:31 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id OyF7DpOGNmVLdwAAMHmgww (envelope-from ); Mon, 23 Oct 2023 14:43:31 +0000 Date: Mon, 23 Oct 2023 16:36:37 +0200 From: David Sterba To: Aleksandr Nogikh Cc: syzbot , clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Dmitry Vyukov Subject: Re: [syzbot] [btrfs?] BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! (4) Message-ID: <20231023143637.GI26353@suse.cz> Reply-To: dsterba@suse.cz References: <000000000000d005440608450810@google.com> <20231023130830.GG26353@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Authentication-Results: smtp-out1.suse.de; none X-Spamd-Result: default: False [-8.30 / 50.00]; ARC_NA(0.00)[]; HAS_REPLYTO(0.30)[dsterba@suse.cz]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; URI_HIDDEN_PATH(1.00)[https://syzkaller.appspot.com/x/.config?x=f27cd6e68911e026]; TAGGED_RCPT(0.00)[b2869947e0c9467a41b6]; REPLYTO_ADDR_EQ_FROM(0.00)[]; REPLY(-4.00)[]; MIME_GOOD(-0.10)[text/plain]; BAYES_HAM(-3.00)[100.00%]; SUBJECT_HAS_QUESTION(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; SUBJECT_HAS_EXCLAIM(0.00)[]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RCPT_COUNT_SEVEN(0.00)[10]; NEURAL_HAM_LONG(-3.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; SUSPICIOUS_RECIPS(1.50)[] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 23, 2023 at 03:30:16PM +0200, Aleksandr Nogikh wrote: > On Mon, Oct 23, 2023 at 3:15 PM David Sterba wrote: > > > > On Sat, Oct 21, 2023 at 07:40:53PM -0700, syzbot wrote: > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 78124b0c1d10 Merge branch 'for-next/core' into for-kernelci > > > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1557da89680000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=f27cd6e68911e026 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=b2869947e0c9467a41b6 > > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > > userspace arch: arm64 > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=137ac45d680000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16e4640b680000 > > > > > > Downloadable assets: > > > disk image: https://storage.googleapis.com/syzbot-assets/bd512de820ae/disk-78124b0c.raw.xz > > > vmlinux: https://storage.googleapis.com/syzbot-assets/a47a437b1d4f/vmlinux-78124b0c.xz > > > kernel image: https://storage.googleapis.com/syzbot-assets/3ae8b966bcd7/Image-78124b0c.gz.xz > > > mounted in repro: https://storage.googleapis.com/syzbot-assets/d5d514495f15/mount_0.gz > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+b2869947e0c9467a41b6@syzkaller.appspotmail.com > > > > > > BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! > > > > #syz invalid > > > > This is a frequent warning, can be worked around by increasing > > CONFIG_LOCKDEP_CHAINS_BITS in config (18 could be a good value but may > > still not be enough). > > By invalidating a frequently occurring issue we only cause syzbot to > report it once again, so it's better to keep the report open until the > root cause is resolved. There'll likely be a report (5) soon. The root cause is somewhere in lockdep and not easy to fix so we'll have to see the duplicate reports or > We keep CONFIG_LOCKDEP_CHAINS_BITS at 16 for arm64 because (at least > in 2022) the kernel used not to boot on GCE arm64 VMs with > CONFIG_LOCKDEP_CHAINS_BITS=18. Maybe it's time to try it once more. yeah, you can increase the config value.