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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 472F0C433F5 for ; Wed, 20 Oct 2021 06:01:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A3DA6113D for ; Wed, 20 Oct 2021 06:01:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229878AbhJTGDu (ORCPT ); Wed, 20 Oct 2021 02:03:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229715AbhJTGDp (ORCPT ); Wed, 20 Oct 2021 02:03:45 -0400 Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B989C06161C for ; Tue, 19 Oct 2021 23:01:32 -0700 (PDT) Received: by mail-oi1-x22d.google.com with SMTP id o83so8362971oif.4 for ; Tue, 19 Oct 2021 23:01:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IIod1o3qhCZvdW0ahsuaYBYhDgjj8nBMGLLNc7+K8Sw=; b=ZssLsRHBs4knpZ/LNOGmB6tMsO7Vf8u3B+7q4N/kKhDJ+qFdXnqnTp1l0TdZ6AGLXg eCEIQMclebzzVTUemUlS2Nr2qEs8vKNOfmBfh+bIdPvdWQpSmAE5IRSnvJ+ZMVo27Mqz 2sWXtztztjlj1Z+Dlt/8yNncFRd6KxlysKCaatYnrSdmdgKjjaa4LZZxRMIjG1BtmDkw LRxLyS+VPGvn6fQhbllcntcVt7j1ZewPEeaaUrvMRrRsv4tpoXa7fw0uqBSBNtWniPXm JriYxB5AwpwqKFEleoGSEZLZWw2KGeNyZBqMGUs4Ea60g3hCAo8bFlW1p3SPzuzTGzRp WCnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=IIod1o3qhCZvdW0ahsuaYBYhDgjj8nBMGLLNc7+K8Sw=; b=UpxyfdYiSYQB8g9lkZWpnSqsitx7hFHfu0Qgi+cdL/wBG+yPDJB2zBwq2C3oOMKuJq fht8ZfDyXvtp6WDJYgjMGrsU3Q9NgeOZgBHDNrun0MTr8hNA6vnDbgVrMdRBBSntoZSu xyrCAA8xYHbgFkFhvzYAZ1Q2zhTOjYY27hRwl0lgFTKgGgTRQ4byZPQqJS1sFRMTXPA/ pnKLLo4SrWVDIKF4DvAyvqWYb7F6hHwofX8DE/Y87a4k9XfG6HN/t1zkHgvZh/pTikxM XmulJK085hDxDzk/aFcMlHwNvfOPui2seV0Mk5Sml2tlUdHUYw2inby6TtsUGDjXdeau Yllw== X-Gm-Message-State: AOAM531PLRTHrRRujwru9kGLs57Lxo7q5R2s+k0+z8HRed10gE4EBvjZ X7YyB8J8jhR6ZwsFhF6EjTCSPvKQXlLrtL0yiH6Lfw== X-Google-Smtp-Source: ABdhPJzd5qvCHYDQgSADJn7obJ/Nig85wI9Xg4OLC0YNlR1f8iwE9Xx9T55lvywUl29R/cQIuk2QANtojG3mUeF0n6s= X-Received: by 2002:a05:6808:191c:: with SMTP id bf28mr7691641oib.7.1634709688231; Tue, 19 Oct 2021 23:01:28 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Wed, 20 Oct 2021 08:00:00 +0200 Message-ID: Subject: Re: BUG: soft lockup in __kmalloc_node() with KFENCE enabled To: Andrea Righi Cc: Dmitry Vyukov , Alexander Potapenko , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 11 Oct 2021 at 16:42, Andrea Righi wrote: > On Mon, Oct 11, 2021 at 12:03:52PM +0200, Marco Elver wrote: > > On Mon, 11 Oct 2021 at 11:53, Andrea Righi wrote: > > > On Mon, Oct 11, 2021 at 11:23:32AM +0200, Andrea Righi wrote: > > > ... > > > > > You seem to use the default 20s stall timeout. FWIW syzbot uses 160 > > > > > secs timeout for TCG emulation to avoid false positive warnings: > > > > > https://github.com/google/syzkaller/blob/838e7e2cd9228583ca33c49a39aea4d863d3e36d/dashboard/config/linux/upstream-arm64-kasan.config#L509 > > > > > There are a number of other timeouts raised as well, some as high as > > > > > 420 seconds. > > > > > > > > I see, I'll try with these settings and see if I can still hit the soft > > > > lockup messages. > > > > > > Still getting soft lockup messages even with the new timeout settings: > > > > > > [ 462.663766] watchdog: BUG: soft lockup - CPU#2 stuck for 430s! [systemd-udevd:168] > > > [ 462.755758] watchdog: BUG: soft lockup - CPU#3 stuck for 430s! [systemd-udevd:171] > > > [ 924.663765] watchdog: BUG: soft lockup - CPU#2 stuck for 861s! [systemd-udevd:168] > > > [ 924.755767] watchdog: BUG: soft lockup - CPU#3 stuck for 861s! [systemd-udevd:171] > > > > The lockups are expected if you're hitting the TCG bug I linked. Try > > to pass '-enable-kvm' to the inner qemu instance (my bad if you > > already have), assuming that's somehow easy to do. > > If I add '-enable-kvm' I can triggering other random panics (almost > immediately), like this one for example: Just FYI: https://lkml.kernel.org/r/20211019102524.2807208-2-elver@google.com But you can already flip that switch in your config (CONFIG_KFENCE_STATIC_KEYS=n), which we recommend as a default now. As a side-effect it'd also make your QEMU TCG tests pass.