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 BDA3FEB64D8 for ; Tue, 20 Jun 2023 17:19:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230041AbjFTRTU (ORCPT ); Tue, 20 Jun 2023 13:19:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229694AbjFTRTT (ORCPT ); Tue, 20 Jun 2023 13:19:19 -0400 Received: from mail-oi1-x233.google.com (mail-oi1-x233.google.com [IPv6:2607:f8b0:4864:20::233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3320511C; Tue, 20 Jun 2023 10:19:18 -0700 (PDT) Received: by mail-oi1-x233.google.com with SMTP id 5614622812f47-394c7ba4cb5so3256667b6e.1; Tue, 20 Jun 2023 10:19:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687281557; x=1689873557; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=WmCprH+idanaTAuo2dvFzhcGXyTLAiyj5xkHxuQVXTU=; b=b9lHqrbagfr1RSGyhYN77p4kcA/eHb4NKgN16tHcbxlk8o72r0HdwtasyTOHARltWD C/E82gKtEmrd4NpGBjaRFuww/h40qL0AfXOHeEvlXReEGa/3ENiah0Gce1po/Hu5MBfH NHqy0OE1EXnomjjuY1iicVoEUf4vyoVYLymygmw2KKkeT8i+ZrPnKE96GdYrgTDyaRIB ZV9hvI/ilx024AGepjkwoOEVvWApcD9JvxTUX52ZVxsF0+6FGcbPM+c4i00rm1N1iv2h dOp4RnvtAyaI5f9WpFdroMUvIvKJd+mcut+phNZHdiuqhx2VDf9Usn7eDjWnp+i/62rX FL0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687281557; x=1689873557; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WmCprH+idanaTAuo2dvFzhcGXyTLAiyj5xkHxuQVXTU=; b=DJgzcBFcTbA3JmKKOWpmhLqZtFz3/KudB7HtcZ5MFNYwU7wP2bw/6ivA8RV5YsOJD3 gMgH6jcd1jYyHN0LI4DaFFmVBu4YlNQGLptj1QevWwZWovCc8cjtweIaPe7siVhh/wms 0C63yvZ0p/KrxXmxKBM8I++G1DpbeTO/29CQXeyMqxkt+ZZP8mjD4k0fkloBx8D6PqTT f4Sgdsq7BhtM8rL+q/B54585odxGpn7PjwA4AZrUdBItaVGv0n78p/X8F52bMqfMLZ9R 1D6/F+mf/mDHJLgC6ZuC0zgeT/8uu00GACoQR4FRhBun9lwrdjlqCSKu8H0zOc3c1KkX fqEw== X-Gm-Message-State: AC+VfDyRpe4WEBUA0OQfooq6JcQQPL6Ga+Fay4G/RYRvm+Y68OEot+t6 jweqyt7Et9cCA3bJv3vnwBigH6NIMrpy70mKS6g= X-Google-Smtp-Source: ACHHUZ48AUCk89CwU1xZqpN0N9tbmO9d1ar83T9TqB8/AUAW9KqhF6B8cLTq3zwM5FrnfvvltVLs7q41z0lnrCLjlyM= X-Received: by 2002:a05:6808:1b0f:b0:39a:aafd:dda7 with SMTP id bx15-20020a0568081b0f00b0039aaafddda7mr15864716oib.35.1687281557150; Tue, 20 Jun 2023 10:19:17 -0700 (PDT) MIME-Version: 1.0 References: <20230614095158.1133673-1-elver@google.com> In-Reply-To: From: Andrey Konovalov Date: Tue, 20 Jun 2023 19:19:06 +0200 Message-ID: Subject: Re: [PATCH] kasan, doc: note kasan.fault=panic_on_write behaviour for async modes To: Marco Elver Cc: Andrew Morton , Alexander Potapenko , Dmitry Vyukov , Taras Madan , Aleksandr Nogikh , Andrey Ryabinin , Vincenzo Frascino , Jonathan Corbet , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Catalin Marinas Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 20, 2023 at 7:17=E2=80=AFPM Marco Elver wrot= e: > > Note the behaviour of kasan.fault=3Dpanic_on_write for async modes, since > all asynchronous faults will result in panic (even if they are reads). > > Fixes: 452c03fdbed0 ("kasan: add support for kasan.fault=3Dpanic_on_write= ") > Signed-off-by: Marco Elver > --- > Documentation/dev-tools/kasan.rst | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/= kasan.rst > index 7f37a46af574..f4acf9c2e90f 100644 > --- a/Documentation/dev-tools/kasan.rst > +++ b/Documentation/dev-tools/kasan.rst > @@ -110,7 +110,9 @@ parameter can be used to control panic and reporting = behaviour: > - ``kasan.fault=3Dreport``, ``=3Dpanic``, or ``=3Dpanic_on_write`` contr= ols whether > to only print a KASAN report, panic the kernel, or panic the kernel on > invalid writes only (default: ``report``). The panic happens even if > - ``kasan_multi_shot`` is enabled. > + ``kasan_multi_shot`` is enabled. Note that when using asynchronous mod= e of > + Hardware Tag-Based KASAN, ``kasan.fault=3Dpanic_on_write`` always pani= cs on > + asynchronously checked accesses (including reads). > > Software and Hardware Tag-Based KASAN modes (see the section about vario= us > modes below) support altering stack trace collection behavior: > -- > 2.41.0.185.g7c58973941-goog > Reviewed-by: Andrey Konovalov