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=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 14373C63697 for ; Thu, 19 Nov 2020 14:06:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89D94246CA for ; Thu, 19 Nov 2020 14:06:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bsolWNpn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727311AbgKSOFu (ORCPT ); Thu, 19 Nov 2020 09:05:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726860AbgKSOFu (ORCPT ); Thu, 19 Nov 2020 09:05:50 -0500 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1856C0613CF for ; Thu, 19 Nov 2020 06:05:49 -0800 (PST) Received: by mail-qv1-xf42.google.com with SMTP id e14so2867389qve.3 for ; Thu, 19 Nov 2020 06:05:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WwhLnjKmfO1PcOKwdzaacmsqx0wVjbnjomFHjf3z3Tg=; b=bsolWNpnC/pFsB2MhVRbEL4kOuL05TlE0WZO3+bEQaXyw/4UbaDjBM31NbhYhfB+pS tMnjYDqXpRNr4w3tgS09iW7o4lduc7MQqsrYC7Cquh892dqLLHU2/L9K6TUoNXrW+50Q z/yLtLNriJ3Qy47EX7h798dDkssO2KZ8smLd5JHSKwwC7cXyJtqsdH8lk+nuXS88PW0f E/6roR4XJV0NfrHEAhKD+wGnT1Vp+bimxmSfRgUj6JgToFxnAIwSbIb3W/RamXtIO2nB sZqWVEkNCzsen6Ir2//77SlMRUbXmTLqgOdDFm4Gv3L0txNIoyGb8MFxNxtLTKr38t7/ xO0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WwhLnjKmfO1PcOKwdzaacmsqx0wVjbnjomFHjf3z3Tg=; b=bEL9Rx4QgTeR7OsFw9VGRNrZbSqNifNQUQVViZiKVYuuYZzEghKe4AsXlzaUhFsgPm IfsmIIdmru+/D2mogWXb1ISZRtiWdmvU8tU0kPbBxGNx6FEIiUhQ2Yurv1nSmu9De4xI oWoIppP9uXl9YI7lX0hag5JN4x530zLZBnpHhjfUJwjI+Smp6Gpbe+DTDLzbB8vMao2R VTdiCEPYbfWLX1V/UIPLmVX/aI0nlgWZuxSknr0BaiUXQuBWqfISiuu3Ezpg+K1BEfrT Lwk5bqbhwHGXTJTF+jAeOtvDdmEcQ7xeY6IQa3ccSsMwoEa2BOHxYNi7vkPXs4aq9iX2 aaZQ== X-Gm-Message-State: AOAM531D0jSBMRsFLospPb5BbteZH9j/2iUnQpAzqfdfObunoNYNQ6v2 hJGFEsLGPjlvJw26Np/yssMeB5PIM6nv3yGfIv00ug== X-Google-Smtp-Source: ABdhPJwhiueb4S7wo/k5WyWEVz3WPmf0oZ/uGmB9NjIGdbn0kh5S8id46EnwssgGjSPwche/7WG9CC2iNmc2G2RtpQQ= X-Received: by 2002:a05:6214:12ed:: with SMTP id w13mr10766898qvv.23.1605794748624; Thu, 19 Nov 2020 06:05:48 -0800 (PST) MIME-Version: 1.0 References: <1595640639-9310-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <384ce711-25c5-553b-8d22-965847132fbd@i-love.sakura.ne.jp> <0eb519fa-e77b-b655-724a-4e9eecc64626@i-love.sakura.ne.jp> <6933e938-f219-5e13-aee6-fe4de87eb43e@i-love.sakura.ne.jp> <81ab0ffd-6e80-c96c-053a-b1b4fe8694c1@i-love.sakura.ne.jp> <20201118142357.GW3121392@hirez.programming.kicks-ass.net> <1778f2e5-0a0c-2c6e-2c83-fe51d938e8a2@i-love.sakura.ne.jp> <20201118151038.GX3121392@hirez.programming.kicks-ass.net> <9bc4e07d-2a58-077b-b4c7-ab056ba33cf1@i-love.sakura.ne.jp> <5e8342c4-702f-80a9-e669-8a7386ce0da1@i-love.sakura.ne.jp> In-Reply-To: <5e8342c4-702f-80a9-e669-8a7386ce0da1@i-love.sakura.ne.jp> From: Dmitry Vyukov Date: Thu, 19 Nov 2020 15:05:36 +0100 Message-ID: Subject: Re: [PATCH v3] lockdep: Allow tuning tracing capacity constants. To: Tetsuo Handa Cc: syzkaller , Ingo Molnar , Will Deacon , Andrew Morton , LKML , Linus Torvalds , Peter Zijlstra Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 19, 2020 at 2:45 PM Tetsuo Handa wrote: > > On 2020/11/19 22:06, Dmitry Vyukov wrote: > >>>> > >>>> I am trying to reproduce this locally first. syzbot caims it can > >>>> reproduce it with a number of very simpler reproducers (like spawn > >>>> process, unshare, create socket): > >>>> https://syzkaller.appspot.com/bug?id=8a18efe79140782a88dcd098808d6ab20ed740cc > >>>> > >>>> I see a very slow drift, but it's very slow, so get only to: > >>>> direct dependencies: 22072 [max: 32768] > >>>> > >>>> But that's running a very uniform workload. > >>>> > >>>> However when I tried to cat /proc/lockdep to see if there is anything > >>>> fishy already, > >>>> I got this (on c2e7554e1b85935d962127efa3c2a76483b0b3b6). > >>>> > >>>> Some missing locks? > > Not a TOMOYO's bug. Maybe a lockdep's bug. > > > > > But I don't know if it's enough to explain the overflow or not... > > > > Since you can't hit the limit locally, I guess we need to ask syzbot to > run massive testcases. I am trying to test the code that will do this. Otherwise we will get days-long round-trips for stupid bugs. These files are also quite huge, I afraid that may not fit into storage. So far I get to at most: lock-classes: 2901 [max: 8192] direct dependencies: 25574 [max: 32768] dependency chains: 40605 [max: 65536] dependency chain hlocks used: 176814 [max: 327680] stack-trace entries: 258590 [max: 524288] with these worst offenders: # egrep "BD: [0-9]" /proc/lockdep 00000000df5b6792 FD: 2 BD: 1235 -.-.: &obj_hash[i].lock 000000005dfeb73c FD: 1 BD: 1236 ..-.: pool_lock 00000000b86254b1 FD: 14 BD: 1111 -.-.: &rq->lock 00000000866efb75 FD: 1 BD: 1112 ....: &cfs_b->lock 000000006970cf1a FD: 2 BD: 1126 ----: tk_core.seq.seqcount 00000000f49d95b0 FD: 3 BD: 1180 -.-.: &base->lock 00000000ba3f8454 FD: 5 BD: 1115 -.-.: hrtimer_bases.lock 00000000fb340f16 FD: 16 BD: 1030 -.-.: &p->pi_lock 00000000c9f6f58c FD: 1 BD: 1114 -.-.: &per_cpu_ptr(group->pcpu, cpu)->seq 0000000049d3998c FD: 1 BD: 1112 -.-.: &cfs_rq->removed.lock 00000000fdf7f396 FD: 7 BD: 1112 -...: &rt_b->rt_runtime_lock 0000000021aedb8d FD: 1 BD: 1113 -...: &rt_rq->rt_runtime_lock 000000004e34c8d4 FD: 1 BD: 1112 ....: &cp->lock 00000000b2ac5d96 FD: 1 BD: 1127 -.-.: pvclock_gtod_data 00000000c5df4dc3 FD: 1 BD: 1031 ..-.: &tsk->delays->lock 00000000fe623698 FD: 1 BD: 1112 -...: per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu) But the kernel continues to crash on different unrelated bugs...