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dkim=pass (1024-bit key; unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=a0NLp93G; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=dev.jain@arm.com; receiver=lists.ozlabs.org) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4j7fSx5KSDz2y8W for ; Tue, 20 Oct 2026 02:23:28 +1100 (AEDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7B83E1682; Mon, 19 Oct 2026 08:22:54 -0700 (PDT) Received: from [10.164.19.55] (unknown [10.164.19.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7207A3F7D8; Mon, 19 Oct 2026 08:22:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1792423377; bh=afNyowLBYnd/bJcBytrONkPV+T5KeD/gmV5hsWmX/oI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=a0NLp93G3qNigo9o3p9//UAu6QuGjeI7Wda5F+kjTem5KJy9fD2LHN8hQo3SVJTzp kdsfz0SYrBlst0J3RUOENQkFxluaiflLW4x4rEZeyAje7QbLwdwbuhsMiRvYW8KR9X DaxRC/1RaWLCyOmHY0TvnlublfXFBQ8P31CrE8VM= Message-ID: <3cbb17e3-e201-4138-a070-0c64289a12bb@arm.com> Date: Mon, 19 Oct 2026 20:52:48 +0530 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , Precedence: list X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/5] mm/kmsan: skip vunmap_range_noflush when KMSAN is disabled To: Hao Ge , Suren Baghdasaryan , Uladzislau Rezki , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Sashiko , stable@vger.kernel.org References: <20261019054531.87652-1-hao.ge@linux.dev> <20261019054531.87652-3-hao.ge@linux.dev> Content-Language: en-US From: Dev Jain In-Reply-To: <20261019054531.87652-3-hao.ge@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_ZEN_BLOCKED_OPENDNS,SPF_HELO_PASS, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 19/10/26 11:15 am, Hao Ge wrote: > kmsan_vmap_pages_range_noflush() returns 0 when kmsan_enabled is > false. The unmap side does not, so it still walks the shadow and > origin page tables even though KMSAN never installed any metadata > there. > > Add the matching early return. > > Reported-by: Sashiko > Cc: stable@vger.kernel.org Cc stable without fixes? I guess without the fix nothing is actually wrong, except doing wasteful work? > Signed-off-by: Hao Ge > --- > mm/kmsan/hooks.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c > index a706666db097..107f66841274 100644 > --- a/mm/kmsan/hooks.c > +++ b/mm/kmsan/hooks.c > @@ -138,6 +138,9 @@ static unsigned long vmalloc_origin(unsigned long addr) > > void kmsan_vunmap_range_noflush(unsigned long start, unsigned long end) > { > + if (!kmsan_enabled) > + return; > + > __vunmap_range_noflush(vmalloc_shadow(start), vmalloc_shadow(end)); > __vunmap_range_noflush(vmalloc_origin(start), vmalloc_origin(end)); > flush_cache_vmap(vmalloc_shadow(start), vmalloc_shadow(end));