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=-23.2 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, URIBL_BLOCKED,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 A13FDC4338F for ; Thu, 12 Aug 2021 08:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8205760C3F for ; Thu, 12 Aug 2021 08:56:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235320AbhHLI5L (ORCPT ); Thu, 12 Aug 2021 04:57:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231470AbhHLI5J (ORCPT ); Thu, 12 Aug 2021 04:57:09 -0400 Received: from mail-ot1-x333.google.com (mail-ot1-x333.google.com [IPv6:2607:f8b0:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92338C061765 for ; Thu, 12 Aug 2021 01:56:44 -0700 (PDT) Received: by mail-ot1-x333.google.com with SMTP id a7-20020a9d5c870000b029050333abe08aso6825727oti.13 for ; Thu, 12 Aug 2021 01:56:44 -0700 (PDT) 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=I29wkPGgO6NQxXu1JpY/V8GMi3CkTzzZeeIK4bDLNvw=; b=hPI9bp/GgD3uadRZs5kcsIl69srGX7pVP0jPT7j4+7TjdukraPt/2fC5KjSZdUtDK0 GwJ7Rw20XqSDVdVdK4127Esn7GOOo4CE+sF3/YDmj/5SRuplEtudLxg+D9CgUW5X3IlO 71a7suz8Q9qNFRjfauG2yppj9kMrIKV2cMlHCAf4ZPdfjUAF/T5N/OgDueZqHH5/k3/1 yvbYu6vuoUntbI02+V/qZbe+AUZNLNQ4niSrUa/LYj2ZZ7s8J7aiAMGH6EBhuqNa8D2s 2Erk+lofy/R3VUHm9Y0G44/X+Vybl/231VoIiHU+MjGRlTsaoVFUTowHhRidKYvrvcNB 9CsA== 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=I29wkPGgO6NQxXu1JpY/V8GMi3CkTzzZeeIK4bDLNvw=; b=WsQwitabX6i4KxDHJ26tYYQxu1FnPr/bZGWEacY0S1eKgyfVN7ygBUF60Usu/U/v5/ wggXjNWNushbsuu9FLiIJ8RIE0BO1ka4AHT5FnsLM8oJ/4BjvnJNUiuw6+oqnCy/byYT WWZVCDCk8RIh3SD5cyKi4jwr6R0YryHjswsslss2Vh30KSsDCBCUVY5M5qr7kBkqNHyC VeRHEN/47Ey0vtqo3SIcQ3P0q6g+4X5I4Nd4n768DHm6t7OzidaCX14iBPqAAGjLySje 0aawulOy6z8cnXoWJP2WrTDkErRJ52OyfDDXkSYMtoaFh3aTVLLZZ3jZdB3ZBRPXgk7h SIRQ== X-Gm-Message-State: AOAM531emt6qpczYq3EjJQCicJfu3fjH6oip2yt9iH22IDSXRo0QGEOr lTy94d8agYaF5p+IVMQA4GQh8aaYKivMuGBJWF+8JA== X-Google-Smtp-Source: ABdhPJy8FvklqUSYdwBSErFoY2cJHDYfrxOpkSc5UNUD8X1LYr4yBN3B1qyJT2tNPqPct+1wdHhbKvh4i3PrtBTNtug= X-Received: by 2002:a05:6830:1490:: with SMTP id s16mr2632529otq.233.1628758603786; Thu, 12 Aug 2021 01:56:43 -0700 (PDT) MIME-Version: 1.0 References: <3773f984cbd64f008af9b03e82fc1b317cda9fda.1628709663.git.andreyknvl@gmail.com> In-Reply-To: <3773f984cbd64f008af9b03e82fc1b317cda9fda.1628709663.git.andreyknvl@gmail.com> From: Marco Elver Date: Thu, 12 Aug 2021 10:56:32 +0200 Message-ID: Subject: Re: [PATCH 6/8] kasan: test: clean up ksize_uaf To: andrey.konovalov@linux.dev Cc: Andrew Morton , Andrey Konovalov , Andrey Ryabinin , 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 Wed, 11 Aug 2021 at 21:23, wrote: > > From: Andrey Konovalov > > Some KASAN tests use global variables to store function returns values > so that the compiler doesn't optimize away these functions. > > ksize_uaf() doesn't call any functions, so it doesn't need to use > kasan_int_result. Use volatile accesses instead, to be consistent with > other similar tests. > > Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Although I do wonder if the compiler might one day mess with the volatile reads. At least this way we might also catch if the compiler messes up volatile reads. ;-) > --- > lib/test_kasan.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > index efd0da5c750f..e159d24b3b49 100644 > --- a/lib/test_kasan.c > +++ b/lib/test_kasan.c > @@ -731,8 +731,8 @@ static void ksize_uaf(struct kunit *test) > kfree(ptr); > > KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr)); > - KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *ptr); > - KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *(ptr + size)); > + KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]); > + KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]); > } > > static void kasan_stack_oob(struct kunit *test) > -- > 2.25.1 >