From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED214363C43; Fri, 11 Sep 2026 15:02:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789138947; cv=none; b=JHfHQsh+Jgslrh1dl90RejAhXQC3TnWSteQ/jNFmkuXMEhyHax9DcLjX3vHa0QpTXpRBWA8vKjWxg556XV1o1my21woKj0GASDBnOMklXO/9qBb+FuGidG/LeWXlGadWJnbxs1KieeTIzEh/sU1HpsiReiXkRCzHA833RaPPE5c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789138947; c=relaxed/simple; bh=mvK0XzUvFQt90JZXu3FumK2Xs8BGJgqQg63kn1EarA0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=opwTL/SgoM5ogtG9BW4zzydS1AXGLPCgkTODh/iI/JdE7uDaD+cK/PN9bSH4Vks2wcNq7tV/+FrX+D4+WvvFr+veRU95MAcKSzYwpKDg1i7rVyfecf0vxrVLpLzancf3s+I2s85R8bE7RxTg7Jut5XgMYFIa3PX116PlhLml8sQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VZh6a5er; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VZh6a5er" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 138301F000FF; Fri, 11 Sep 2026 15:02:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789138945; bh=1PTWyg4n3qpD4y/aa8UvIgM/ayJsqmzhh3ejIEE3QXI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=VZh6a5erCAhSab9ROCtz8BS6g7MI1jzhVXl1TxFBYM68Z+fltaZm1xEx6OLItP15Z nZmBVnNP1V+0/DmEZx6SzFV84s9DU1Cqc3gJdZgKEuLrXE8ZBhvx4UTF2zsQJmzQrU 1ESbS6pHuZFLaLsWPyN7kq3K9C94jNU3KLadDp0qGGPb0YqI8SxZOaAh8rd/J0rPK5 N7z3J3PXvkWkYOSJwSDPZrWHYbCcf4HyZ5juLbh027S7qlmCWyKCaa/zsagr+fkbEo rjY7sSzeoe/K7U4vNDmzPmvaXdunSPEXnnKxmE3D1cRrG2OGu0oUCAh5OqIXCJVYCC jemxJj67wfX/Q== Message-ID: <62160d6e-5409-4249-814b-cdc33b7d29df@kernel.org> Date: Fri, 11 Sep 2026 17:02:20 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] kselftest: mm: fix potential failure for merged VMA in guard-regions To: Yeoreum Yun , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com References: <20260911142904.1825452-1-yeoreum.yun@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/11/26 16:29, Yeoreum Yun wrote: > check_vmflag_guard() uses /proc/self/smaps to retrieve the VMA flags, > but this can fail if the mapping is merged with an adjacent VMA. > > To avoid this potential failure, first allocate a temporary region with > extra pages at both ends, unmap it, and then map the test region within > the temporary address range, leaving an unmapped page on each side to > prevent VMA merging. > > Signed-off-by: Yeoreum Yun > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David