From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.22 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794468699; b=YYuRn2SUxHGKxNxH7GER62c+BJOn+V5ISXKj+bh8tc+Q86HwCoa7EA/OLRuQNkFh7vN6 uAvkHXr0yJ5a5Ifis+ox36BOeoL76XDDp53tnrjULtr3IKqePx5+fxPtlHAwS6zdMkb0q gHYGGxMNhro9qRBFfueLRp8tYnxmoMDNdyb1+BRcEo1+t60Qm+fLcY5IjIUtrpobFwII2 DuJri6DkmSdY1H2WJB8wxnMvi0wGugXFP0ZXYFo8SuLe73W7RmxGJCDUEZnSo+1Wnxxjz rvTVAKq/K7gaHuEFh1Omhfp/OHAa8OaHTnGMVyCI0bZ4qF2iVov43FH8ym2apfWW0jA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794468699; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=YkSv46yCHtIqoXvtaUlGuoA5bkCcyG3dKOTi+O8s+8o=; b=nhfTqvq9jWYmh3wlEvc1BpwGs+ekjl89p+mOzix3t53H5aPFAwWbO246eF8xDc7SdWx8 FiD5JVSwsf10/TaVu8uApBWZIrDqVQ4NePnPjt2BxzwYe028i4RWz/KdPdBTKUJ55ass2 CnUZUuPvPopBP5G59TG7rkKE/8SCc12jlZPDrkNy5gIrROAQUHfMhN4PUw8clOmG2BVCb LnQF+euJDXTd0COuiuvEEzn4X9LmROV5Osnq/iRPfwipXMUrfAfQbm5OpJSni/xyWUXYV 3N4+bAAxqFcVdFn1uPI0j7VuTeHcRANOJ3Iyr9xpeoKGty2yxzVREYxWvBHpDxpqItA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=NA+Y8Lq+; arc=none smtp.remote-ip=91.218.175.22 Received: from mta0.migadu.com (out-22.mta0.migadu.com [91.218.175.22]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C59EF606A31C for ; Thu, 12 Nov 2026 07:31:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C59EF606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=NA+Y8Lq+ X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=c6rVmPURZ3DT+JjErkgtV1mxI38IznosT0ADdpGxR3o=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794468695; v=1; x=1795073495; b=NA+Y8Lq+cDGqZtzw4xGR7Z+rYhlYc5kEZj9Wf2Hmn89XoCjPbSUTy0bPCgWjC3gyr6BdN93c dC2ocsMaJpeagEvb78VirV/+2BWUhRbdDe7rev1Y9Mb5hCh5YGA1p4FraGwo6qC7NQCIepltXUr MfBgol3hXaLgGn6MND2cWhuQ= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 13c0695ddd446293; Thu, 12 Nov 2026 07:31:35 +0000 X-Mizu-Trace-ID: 13c0695ddd446293 X-Migadu-Flow: FLOW_OUT Message-ID: <7df44933-e92e-4f1c-9b26-22a1a298ca16@linux.dev> Date: Thu, 12 Nov 2026 15:32:58 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/9] mm/kmsan: skip vunmap_range_noflush when KMSAN is disabled To: Suren Baghdasaryan Cc: Uladzislau Rezki , Dev Jain , Andrew Morton , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Dennis Zhou , Tejun Heo , Christoph Lameter , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Sashiko References: <20261110112546.261415-1-hao.ge@linux.dev> <20261110112546.261415-3-hao.ge@linux.dev> Content-Language: en-US From: Hao Ge In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Suren On 2026/11/12 06:10, Suren Baghdasaryan wrote: > On Tue, Nov 10, 2026 at 11:24 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. > > Note that KMSAN_WARN_ON() can reset kmsan_enabled flag, so the fact > that it's false does not mean that metadata was never installed. I > think a proper bailout should depend on CONFIG_KMSAN, not on > kmsan_enabled. Sorry, I did not realize this logic. I will go through the code again and will probably drop this patch in the next version. Thanks Best Regards Hao > >> >> Add the matching early return. >> >> Reported-by: Sashiko >> Reviewed-by: Dev Jain >> 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)); >> -- >> 2.25.1 >>