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 EB4DBC433EF for ; Sat, 27 Nov 2021 19:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239143AbhK0T4f (ORCPT ); Sat, 27 Nov 2021 14:56:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243672AbhK0Tye (ORCPT ); Sat, 27 Nov 2021 14:54:34 -0500 Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D005C0613D7 for ; Sat, 27 Nov 2021 11:48:37 -0800 (PST) Received: by mail-ed1-x530.google.com with SMTP id r11so53522533edd.9 for ; Sat, 27 Nov 2021 11:48:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=k+WD13DnrXMzqv5sT4ElYQPrredLdicNs7FcvpypMvw=; b=ggD12LSgQGpOuKA978T0sePFYeQGzUd++Kya77nHEr8H2Y5U3s7Zev6jYWlM8g15zO 5Nx2G7t6c+rf7GGAFSCpQZHxkt5OsQEtBXocSqZLsTflKlP069Y6vTvdom+R8sqCaKUw raWaWu426UTiqy4O9nfelPn8PFHOxakZIgTU2W7kcNGQpO0/++2YRvyDr2I3SrXmDQDu 1WXMLGMEZkRCaF0fcMj7B97yK/UvWka83ZyeYu2k+zh5GsHFtnmwVVhil+n7bNYTEFKF X7uNLZtrn4UGiqMgjSrR41qUhKmTbXBfSPwcJban6ogspnPTMJr2I3EqiFsJEdHq0nAW GO1w== 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=k+WD13DnrXMzqv5sT4ElYQPrredLdicNs7FcvpypMvw=; b=4BrdhYpMk7qhIw8SOugXJkSWzrM6Lsq9J/Esm7C9GfqZS9DpLYOojYlD/xe/1N5WNc UNj7knFagRpXJ85nw0osYBZgpfsxMVVWX6WynkIOf6B1nO/8kALO7XtLxgsKah4YuNr3 JLnsRKDx5UMqKNScsDdSM8TOFEGq7/1bZ3j4X2H1Jaa7390/RZYlEZw2do7v65CcOLV/ eGfCzAeL1I3kVhg1VXX5BIezrsrozA8F3Y28qUTsehm6VobcOKnhC2GZjFNpvC9g5zbM ZTCDJkVluLSRhiiViwdDX57T7GLw55AqzcaWdw9dsv8cN70NY/4w5pS9l8dk4t/TefKI vpAA== X-Gm-Message-State: AOAM5310Ca1SFs8pwNEF1gKRT+rPfDsvrPd6gCa8p5wibmsa3OYkd+2L x9qUogytlmQBsrLT1uHSK2JirRmrgq8qZtuXJ3aGBg== X-Google-Smtp-Source: ABdhPJw0is2PzWlMWDR3TZyj9QAnUHxP4u+3yMhqpCEGNgRGps4GUpD1lk/8f8bPRqTYXYiiKhXliWlL2FAx25XiMY4= X-Received: by 2002:a17:906:58ce:: with SMTP id e14mr46457043ejs.525.1638042515857; Sat, 27 Nov 2021 11:48:35 -0800 (PST) MIME-Version: 1.0 References: <20211123214814.3756047-1-pasha.tatashin@soleen.com> <20211123214814.3756047-3-pasha.tatashin@soleen.com> <6d82e674-76dc-f3b0-2e53-a92eeb249eff@gmail.com> In-Reply-To: <6d82e674-76dc-f3b0-2e53-a92eeb249eff@gmail.com> From: Pasha Tatashin Date: Sat, 27 Nov 2021 14:48:00 -0500 Message-ID: Subject: Re: [PATCH 2/3] mm: page table check To: Fusion Future Cc: LKML , linux-mm , Linux Doc Mailing List , Andrew Morton , David Rientjes , Paul Turner , weixugc@google.com, Greg Thelen , Ingo Molnar , Jonathan Corbet , Will Deacon , Mike Rapoport , Kees Cook , Thomas Gleixner , Peter Zijlstra , masahiroy@kernel.org, Sami Tolvanen , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , frederic@kernel.org, "H. Peter Anvin" , "Aneesh Kumar K.V" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 27, 2021 at 3:41 AM Fusion Future wrote: > > It seems after updating to linux-next-20211125, my system is crashing > frequently due to "kernel BUG at mm/page_table_check.c:101". Thank you for reporting this issue: 99 if (anon) { 100 BUG_ON(atomic_read(&ptc->file_map_count)); 101 BUG_ON(atomic_dec_return(&ptc->anon_map_count) < 0); This BUG_ON checks that during unmap anon map counter (cleared in ptep_clear_flush()) does not become negative. If it becomes negative it means that we missed accounting for this anon mapping during set_pte(). Is there a config and environment that I could use to repro this problem? Thank you, Pasha