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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B687FC433EF for ; Wed, 16 Mar 2022 22:11:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 278DE6B0071; Wed, 16 Mar 2022 18:11:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 228A48D0002; Wed, 16 Mar 2022 18:11:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F09A8D0001; Wed, 16 Mar 2022 18:11:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id F40176B0071 for ; Wed, 16 Mar 2022 18:11:11 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 9AA3A60520 for ; Wed, 16 Mar 2022 22:11:11 +0000 (UTC) X-FDA: 79251645942.13.F98118A Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf24.hostedemail.com (Postfix) with ESMTP id CFCD318002B for ; Wed, 16 Mar 2022 22:11:10 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6D91A21110; Wed, 16 Mar 2022 22:11:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1647468669; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=119nUFksKlBDXAU4ZUaELQAYa7682rr7tXjGl/HOxJQ=; b=MmaX13/53I8dtNZoHeP27Mf2o0fapozIxb3rs1C2uJcUhYQARrKFSR7tse3uiWnJMZ3wpP sbs4tCVmwX0b9H0TqncE2CNjdom4ApZ1ed/NwtJVbVYxg/YBDNUb8ddLd4Fq2szUe0IWnb Dbz3URna0h5DEYnMSIMCNLx2a1PPD4g= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1647468669; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=119nUFksKlBDXAU4ZUaELQAYa7682rr7tXjGl/HOxJQ=; b=VeSZj1cpPyD/00JUVANHHFPWlv413UdY6qRzbGklNabrw/QXP2E/ilBkbqbIaWEzg4sqSq 5ou8rLvmRAktyaCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 355F213B5E; Wed, 16 Mar 2022 22:11:09 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WYyWC31gMmJYOwAAMHmgww (envelope-from ); Wed, 16 Mar 2022 22:11:09 +0000 Message-ID: <46456d7a-fd35-5052-f3c0-a97d25345e79@suse.cz> Date: Wed, 16 Mar 2022 23:11:08 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH] mm/slub, kunit: Make slub_kunit pass even when SLAB_RED_ZONE flag is set Content-Language: en-US To: Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Oliver Glitta References: <20220316143841.160373-1-42.hyeyoo@gmail.com> From: Vlastimil Babka In-Reply-To: <20220316143841.160373-1-42.hyeyoo@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: CFCD318002B X-Stat-Signature: aiipeznnbbmedg9hqpnyi74jnsercg5m X-Rspam-User: Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b="MmaX13/5"; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=VeSZj1cp; dmarc=none; spf=pass (imf24.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz X-Rspamd-Server: rspam02 X-HE-Tag: 1647468670-314970 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 3/16/22 15:38, Hyeonggon Yoo wrote: > Testcase test_next_pointer in slub_kunit fails when SLAB_RED_ZONE flag > is globally set. This is because on_freelist() cuts corrupted freelist > chain and does not update cut objects' redzone to SLUB_RED_ACTIVE. > > When the test validates a slab that whose freelist is cut, it expects > redzone of objects unreachable by freelist is set to SLUB_RED_ACTIVE. > And it reports "Left Redzone overritten" error because the expectation > failed. > > This patch makes slub_kunit expect two more errors for reporting and > fixing red overwritten error when SLAB_RED_ZONE flag is set. > > The test passes on slub_debug and slub_debug=Z after this patch. Hmm I think it's not optimal strategy for unit tests to adapt like this to external influence. It seems rather fragile. The test cases should be designed to test a specific condition and that's it. So maybe we could e.g. introduce a new SLAB_ flag passed to kmem_cache_create that tells it to ignore any globally specified slub debug flags? > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > --- > lib/slub_kunit.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c > index 8662dc6cb509..7cf1fb5a7fde 100644 > --- a/lib/slub_kunit.c > +++ b/lib/slub_kunit.c > @@ -45,21 +45,36 @@ static void test_next_pointer(struct kunit *test) > * Expecting three errors. > * One for the corrupted freechain and the other one for the wrong > * count of objects in use. The third error is fixing broken cache. > + * > + * When flag SLUB_RED_ZONE is set, we expect two more errors for reporting > + * and fixing overwritten redzone error. This two errors are detected > + * because SLUB cuts corrupted freelist in on_freelist(), but does not > + * update its redzone to SLUB_RED_ACTIVE. > */ > validate_slab_cache(s); > - KUNIT_EXPECT_EQ(test, 3, slab_errors); > + > + if (s->flags & SLAB_RED_ZONE) > + KUNIT_EXPECT_EQ(test, 5, slab_errors); > + else > + KUNIT_EXPECT_EQ(test, 3, slab_errors); > > /* > * Try to repair corrupted freepointer. > * Still expecting two errors. The first for the wrong count > * of objects in use. > * The second error is for fixing broken cache. > + * > + * When SLUB_RED_ZONE flag is set, we expect two more errors > + * for same reason as above. > */ > *ptr_addr = tmp; > slab_errors = 0; > > validate_slab_cache(s); > - KUNIT_EXPECT_EQ(test, 2, slab_errors); > + if (s->flags & SLAB_RED_ZONE) > + KUNIT_EXPECT_EQ(test, 4, slab_errors); > + else > + KUNIT_EXPECT_EQ(test, 2, slab_errors); > > /* > * Previous validation repaired the count of objects in use.