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=-24.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 5A5D1C11F66 for ; Mon, 12 Jul 2021 16:44:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DAF361186 for ; Mon, 12 Jul 2021 16:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233857AbhGLQrB (ORCPT ); Mon, 12 Jul 2021 12:47:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232369AbhGLQrB (ORCPT ); Mon, 12 Jul 2021 12:47:01 -0400 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9350BC0613E5 for ; Mon, 12 Jul 2021 09:44:12 -0700 (PDT) Received: by mail-wr1-x42c.google.com with SMTP id d2so26582790wrn.0 for ; Mon, 12 Jul 2021 09:44:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=qv3Vo5xsbAOEJgLGiYQjQnACJg9fyGkdPANxzyRJ0u0=; b=YxBBHmI3ihh3rUAZ/HpfxdYI/ND6OwEcRE87eHmz6vpJk0+eabbOKTLzjPAHhaPmZk w32aSCR6KLnikoJXR6BtzDh90JoGuS28RKqIIjENeZZmUYEJbwP8Mrqu2BnPsUkY6leN mlEGsZM2OSF1zTCti5cuAFklbPzZbbkIXnuCMAn4Inb/Yki03iwTSTwuisyOIqeAKTE7 QKASs/Hu4FEREVrYg4reYBvWwaJFvJVrj4KE8PiPEYUzXxveOwK7dY2fS5PtuTd6sNzp aA44ScWsNdRd6mTHuz1xxlWdPTrQHl8oxnscIvCCbhC8KmermcAzaNyALgsZ3A/HUTSi cg/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=qv3Vo5xsbAOEJgLGiYQjQnACJg9fyGkdPANxzyRJ0u0=; b=p0jQiDrrrnostcKYxMlYvgcD/99MvZ8hnvXT+f5likZ4uP9jvoHqkY0tjM5jV+yXcF ys2W4WFpz6KZctgkXuDSYLIfic8uLST615BaFT6y9xuklvOCdgA+loj3YG5geZ/hszNw 8o2TjBsKrx74xKS9QckEil7NXlysdhdItNSm2Zaw19wGPg/t6OkBlgULJJXY7zygTmCa ge3Mnd2TEPYzC55rrpeyl1Nc45HIZx2GfT/s3tmlg5mNSrP2KFSkNBBSW+EMam/rXH6M +OPAVn62rO5f23wRaoOzuetdWn4eFkBiMqBbGFxKGbzgiedhIi7Xznd/Cl3JKCzN+VLs J5jw== X-Gm-Message-State: AOAM531O6b9y3XWHKFHewdxETCYopASvnEzSo6H4w05YTTKGBKdo1Zfb NwXpKYBjyvuf6WkouVr7In8PfQ== X-Google-Smtp-Source: ABdhPJwK3VzhGWa3A0Cjl11xE5bb+9d9dgWz6yHyUkbAZ6XWnHp3BGzBwKSF+UhXsDpR3C0/w/Rt9g== X-Received: by 2002:a5d:530c:: with SMTP id e12mr28211287wrv.130.1626108251006; Mon, 12 Jul 2021 09:44:11 -0700 (PDT) Received: from elver.google.com ([2a00:79e0:15:13:30c:6a5f:a6ae:eba0]) by smtp.gmail.com with ESMTPSA id f2sm14920362wrq.69.2021.07.12.09.44.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Jul 2021 09:44:09 -0700 (PDT) Date: Mon, 12 Jul 2021 18:44:04 +0200 From: Marco Elver To: Woody Lin Cc: Andrey Ryabinin , Dmitry Vyukov , Alexander Potapenko , Andrey Konovalov , Jonathan Corbet , Andrew Morton , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm/kasan: move kasan.fault to mm/kasan/report.c Message-ID: References: <20210712151618.1549371-1-woodylin@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210712151618.1549371-1-woodylin@google.com> User-Agent: Mutt/2.0.5 (2021-01-21) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 12, 2021 at 11:16PM +0800, 'Woody Lin' via kasan-dev wrote: > Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it > can support all KASAN modes - generic, and both tag-based. > > Signed-off-by: Woody Lin > --- > Documentation/dev-tools/kasan.rst | 2 ++ > mm/kasan/hw_tags.c | 43 ------------------------------- > mm/kasan/report.c | 29 ++++++++++++++++++--- > 3 files changed, 28 insertions(+), 46 deletions(-) > > diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst > index 83ec4a556c19..ab8e27d45632 100644 > --- a/Documentation/dev-tools/kasan.rst > +++ b/Documentation/dev-tools/kasan.rst > @@ -203,6 +203,8 @@ boot parameters that allow disabling KASAN or controlling its features. > report or also panic the kernel (default: ``report``). The panic happens even > if ``kasan_multi_shot`` is enabled. > > + Note: The boot parameter 'kasan.fault' is supported by all KASAN modes. This documentation change seems hacked on. Could we change it like this: diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index 83ec4a556c19..21dc03bc10a4 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access. With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This effectively disables ``panic_on_warn`` for KASAN reports. +Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot +parameter can be used to control panic and reporting behaviour: + +- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN + report or also panic the kernel (default: ``report``). The panic happens even + if ``kasan_multi_shot`` is enabled. + Hardware tag-based KASAN mode (see the section about various modes below) is intended for use in production as a security mitigation. Therefore, it supports -boot parameters that allow disabling KASAN or controlling its features. +additional boot parameters that allow disabling KASAN or controlling features: - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``). @@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features. - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack traces collection (default: ``on``). -- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN - report or also panic the kernel (default: ``report``). The panic happens even - if ``kasan_multi_shot`` is enabled. - Implementation details ---------------------- [...] > -/* Whether to panic or print a report and disable tag checking on fault. */ > -bool kasan_flag_panic __ro_after_init; There's also an extern declaration in kasan.h, which should be removed. Thanks, -- Marco