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=-23.3 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_IN_DEF_DKIM_WL autolearn=ham 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 0B384C433B4 for ; Wed, 31 Mar 2021 16:59:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8D27360FEF for ; Wed, 31 Mar 2021 16:59:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D27360FEF Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 033606B0082; Wed, 31 Mar 2021 12:59:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00A136B0085; Wed, 31 Mar 2021 12:59:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E13866B0087; Wed, 31 Mar 2021 12:59:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0044.hostedemail.com [216.40.44.44]) by kanga.kvack.org (Postfix) with ESMTP id C1A146B0082 for ; Wed, 31 Mar 2021 12:59:05 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7DB3E824999B for ; Wed, 31 Mar 2021 16:59:05 +0000 (UTC) X-FDA: 77980779450.18.84A007F Received: from mail-oi1-f180.google.com (mail-oi1-f180.google.com [209.85.167.180]) by imf07.hostedemail.com (Postfix) with ESMTP id C0D04A000390 for ; Wed, 31 Mar 2021 16:59:04 +0000 (UTC) Received: by mail-oi1-f180.google.com with SMTP id i81so20639252oif.6 for ; Wed, 31 Mar 2021 09:59:04 -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=FZftGjdCUXY+05ORZ/0TVog0hvFmuHoMzmlE5jZV4Tc=; b=lPsNsAflRfDN9BHED2vwwFOhw6hY9W+aG2jWeG92q3sTTD0vmhelOEiJ37ORNAjO4o cgN9/6Z2jFRZ4WnsPLjTjuMR0RdkzgFp0XboTwL0Coefeg40oPx15GrNbNI9yn69E7pp arVK1k5JOmR5MgUmdtnh/+rZhNiPjSp196y6w4XsjBqH9DaTIup3A+sSi/7j3D/jHKyD fnkm7XqhBMlWJTExdkAIUdJl99hBWBvB3LKKiIGksSuNjl/iwUkDzmIY6Lw95v3ER5gl E+TygSzkCxcNGlWLBRCjaD6vI7ITcfvSmXTltqn7qBpwi6Af8cfnU2Z569Yd3YXo4RjO FCWA== 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=FZftGjdCUXY+05ORZ/0TVog0hvFmuHoMzmlE5jZV4Tc=; b=rlV4vXO8iSuEpL1atW6ksKHZw4zSkiognq/6LNp+tDHCYuI4W11mwCKxahAvlHGYSJ E4sWB8RTgzsDn6wOG4wz8q99CH88+741/XNG3NGbyAf9GLLwTszQrNK/gkC/VChr3naz iVLAXWlVAqF2UBI4boUdOCoZ/sqvUTsQhyZ04clAdNZfEkE7JXYB8vLJ6vlmxMQiAzNA nlDBWfnk6Ol8EMq4OoxzML37ol067qdGN12+N9rUQDLfEErK/aJGXkzVLgUvHmHn1/V7 xx45XRPhDnTrvLXMf5qEosFAABv4hctNPCRFdVV/cCmTGDDcZcTClTZ0ATuxxYR7un7d dy8A== X-Gm-Message-State: AOAM530WvpzO7ni5UcPIscokwsJO5Bna8QxgiCd02dWNakoe5JhVod0/ hbJnbi3TYccwihm5g4/J36rKNu14uCPIvWooxh8bYA== X-Google-Smtp-Source: ABdhPJwCjLKSSi1/qdcV75GsJNcLlMA0Fv+O5DpIf5jWkUTXDpgz4chaMVhWYqj39CXKRF8meV4oldegxoKwO6Jr3VU= X-Received: by 2002:aca:bb06:: with SMTP id l6mr2893534oif.121.1617209944150; Wed, 31 Mar 2021 09:59:04 -0700 (PDT) MIME-Version: 1.0 References: <48079c52cc329fbc52f4386996598d58022fb872.1617207873.git.andreyknvl@google.com> In-Reply-To: <48079c52cc329fbc52f4386996598d58022fb872.1617207873.git.andreyknvl@google.com> From: Marco Elver Date: Wed, 31 Mar 2021 18:58:52 +0200 Message-ID: Subject: Re: [PATCH] kasan: detect false-positives in tests To: Andrey Konovalov Cc: Andrew Morton , Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , Andrey Konovalov , kasan-dev , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C0D04A000390 X-Stat-Signature: fxbb5fawczofwwqu7nbfxnjsnhd8wrfo Received-SPF: none (google.com>: No applicable sender policy available) receiver=imf07; identity=mailfrom; envelope-from=""; helo=mail-oi1-f180.google.com; client-ip=209.85.167.180 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617209944-770196 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 31 Mar 2021 at 18:25, Andrey Konovalov wrote: > > Currently, KASAN-KUnit tests can check that a particular annotated part > of code causes a KASAN report. However, they do not check that no unwanted > reports happen between the annotated parts. > > This patch implements these checks. > > It is done by setting report_data.report_found to false in > kasan_test_init() and at the end of KUNIT_EXPECT_KASAN_FAIL() and then > checking that it remains false at the beginning of > KUNIT_EXPECT_KASAN_FAIL() and in kasan_test_exit(). > > kunit_add_named_resource() call is moved to kasan_test_init(), and the > value of fail_data.report_expected is kept as false in between > KUNIT_EXPECT_KASAN_FAIL() annotations for consistency. > > Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Thank you! > --- > lib/test_kasan.c | 49 +++++++++++++++++++++++++++--------------------- > 1 file changed, 28 insertions(+), 21 deletions(-) > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > index d77c45edc7cd..bf9225002a7e 100644 > --- a/lib/test_kasan.c > +++ b/lib/test_kasan.c > @@ -54,6 +54,10 @@ static int kasan_test_init(struct kunit *test) > > multishot = kasan_save_enable_multi_shot(); > kasan_set_tagging_report_once(false); > + fail_data.report_found = false; > + fail_data.report_expected = false; > + kunit_add_named_resource(test, NULL, NULL, &resource, > + "kasan_data", &fail_data); > return 0; > } > > @@ -61,6 +65,7 @@ static void kasan_test_exit(struct kunit *test) > { > kasan_set_tagging_report_once(true); > kasan_restore_multi_shot(multishot); > + KUNIT_EXPECT_FALSE(test, fail_data.report_found); > } > > /** > @@ -78,28 +83,30 @@ static void kasan_test_exit(struct kunit *test) > * fields, it can reorder or optimize away the accesses to those fields. > * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the > * expression to prevent that. > + * > + * In between KUNIT_EXPECT_KASAN_FAIL checks, fail_data.report_found is kept as > + * false. This allows detecting KASAN reports that happen outside of the checks > + * by asserting !fail_data.report_found at the start of KUNIT_EXPECT_KASAN_FAIL > + * and in kasan_test_exit. > */ > -#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \ > - if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) \ > - migrate_disable(); \ > - WRITE_ONCE(fail_data.report_expected, true); \ > - WRITE_ONCE(fail_data.report_found, false); \ > - kunit_add_named_resource(test, \ > - NULL, \ > - NULL, \ > - &resource, \ > - "kasan_data", &fail_data); \ > - barrier(); \ > - expression; \ > - barrier(); \ > - KUNIT_EXPECT_EQ(test, \ > - READ_ONCE(fail_data.report_expected), \ > - READ_ONCE(fail_data.report_found)); \ > - if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \ > - if (READ_ONCE(fail_data.report_found)) \ > - kasan_enable_tagging(); \ > - migrate_enable(); \ > - } \ > +#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \ > + if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) \ > + migrate_disable(); \ > + KUNIT_EXPECT_FALSE(test, READ_ONCE(fail_data.report_found)); \ > + WRITE_ONCE(fail_data.report_expected, true); \ > + barrier(); \ > + expression; \ > + barrier(); \ > + KUNIT_EXPECT_EQ(test, \ > + READ_ONCE(fail_data.report_expected), \ > + READ_ONCE(fail_data.report_found)); \ > + if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \ > + if (READ_ONCE(fail_data.report_found)) \ > + kasan_enable_tagging(); \ > + migrate_enable(); \ > + } \ > + WRITE_ONCE(fail_data.report_found, false); \ > + WRITE_ONCE(fail_data.report_expected, false); \ > } while (0) > > #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \ > -- > 2.31.0.291.g576ba9dcdaf-goog >