From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792423379; b=4qxgHoTKD0GROBGUuhcIHfq31CHXDbvgQu81JkVw3cvttWuVMo2ACyFFeHznysi/xEDh YMziITHFJNlkIgA8aUFjjVcrQVwiUcS9I3qzfxSnUqpCu/OGM3Ta9X1ZbXfn6n+fIYQ9B WNuxDJo5HLDpJEuByvkEaqWs5xi8qtO/PxSU6L1OiTNnjzhGZIjpS6CHtN4zV2RWuZTrR inzW93SLceyPG5klBg7N1DtjMDDqQ3WI59e7FFcAhGNHts8vDFgrERB5x6gW6sxGzGuw6 WOvISTDnihn3mNJf090IXdvFFffrDrfyMEWA6zo1EWcaYY4tWivlWUlB86fNvuCJKWg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792423379; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=ES6PScTn//8O/kb4uLeXWJf50MrCERiG7IFUfR8gLMA=; b=pc/eBOJ/BmKx/JLKsWFDDpaWf7Br8Zcc7cp2z16HruS+lkKiWfMcgwm4JHdjtcqndgjT Ubcrq/yF7MMyylvGt5rVhIx1P7fycs4LDeOJbY/pVCIhPaA4YLAeaxm+yLpkEYJ2d+GQP tF+wXNfnqfH+jHoCukdIHQ9tk7f0okrMFUrOfUAlUC+XtTgDdoF+Jl0ZSTam54WGv5szI yOfpeWoXDBY6LcxLXjpYPhpbrmTamibKEY/ra80yttQPsrJYEz1p2PlVvJ14qpQU4zRgp lz/CGMHwPMpkNYsNc6ERI80X/Mo9KY0qFlaT5AruwhTF9kD5ZuPU9pZrXALQEj7Hjmg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=a0NLp93G; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 86E9760AB719; Mon, 19 Oct 2026 15:22:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 86E9760AB719 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=a0NLp93G 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: 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 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 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));