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 55038C369DC for ; Tue, 29 Apr 2025 16:54:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A06316B0007; Tue, 29 Apr 2025 12:54:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9B4996B000E; Tue, 29 Apr 2025 12:54:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8A6316B0010; Tue, 29 Apr 2025 12:54:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 6BC5D6B0007 for ; Tue, 29 Apr 2025 12:54:20 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 5785B160B0F for ; Tue, 29 Apr 2025 16:54:21 +0000 (UTC) X-FDA: 83387679522.10.84F16E5 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf06.hostedemail.com (Postfix) with ESMTP id 97D9218000F for ; Tue, 29 Apr 2025 16:54:19 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=JvCxpf1z; spf=pass (imf06.hostedemail.com: domain of kees@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1745945659; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=GG/5m5DQUeYrAJsioguQY6Pld2MWHItCFZRmIAR0eCQ=; b=mRtz2DS8RXVchRnfn2u/fn1EtZa54JpAnA1ayjolBB/6DY+nFc6tsollB4nfq54rwTnyE6 bHt1syW3IP+pUe6eR3b8i5o0MfC9Q+9e9fnN+ulrYYXIU5W6aH5bufU1bvyDEl/ZmOw91Z p7i3z5TAz4ZRtOKw39xAm5SqIe5pH0I= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=JvCxpf1z; spf=pass (imf06.hostedemail.com: domain of kees@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1745945659; a=rsa-sha256; cv=none; b=etp3E1EAhxEolEfxWfu8ZxTPcq0N6ncij1H/l4tlnnUJxZfzim432ZtWwnRWboqfA3OM+L Pht2J7zxDFtQlDlgTTnFXQljl3qWFWCzCnYCBVrm6+jFbNwwAagyIm3p/fXRyT1iR0Q7C3 2h0Qudu8+IPefGkQWNDs4CDLlVRn0aw= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2DF8645131; Tue, 29 Apr 2025 16:54:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 386C9C4CEE9; Tue, 29 Apr 2025 16:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745945658; bh=++dhepfBhRi0erK+LYv8IWVCWaZFGXckt9RPxoukWxs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JvCxpf1zBWxt7kM/bFBgYrYsVwdvEhgx8DFDqgQezureiY3Ayu7GnmqEwIE5Pq7GN L6W2qSGh70igv0zgSYxP++zBPUJ8is4gXDYl8CCPoMHa0/lePsK0tVy09LkxO4iXEd yoi/SHAnRjszqDaHEpKmGxlBlMV/Sx3RyZJhlVGcN5OlglvJost7IbR2QAtUfwJwuA rpD0tRSpBJ2XLnFhYaWgnZbq3NEXo3YaEN29VwQ5UVlJxuhe7+siV06LROBG6l7/qA HTC2eEpHs0tv30aVV6ftZuS/nRhVCLFdbe4hdksymcwQAlurG5YPZCWqzHLKmic3Jt xjjIDtKPb89Dg== Date: Tue, 29 Apr 2025 09:54:14 -0700 From: Kees Cook To: Lorenzo Stoakes Cc: Andrew Morton , "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Alexander Viro , Christian Brauner , Jan Kara , Suren Baghdasaryan , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/4] mm: move dup_mmap() to mm Message-ID: <202504290954.754D25567A@keescook> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 97D9218000F X-Stat-Signature: 57c3epun5h7c9wnkzq1as8zfjbrdnccm X-HE-Tag: 1745945659-663429 X-HE-Meta: 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 rvy0BM3j LkhmM00gisrVeZRhSylGuvld1ePrSMhcKAcpiPYA3rszMxFPaZxfM/5LuUlyWT99kj/1B1Xg+LQoXZKhRUyOhv6a4yPlBlsQbuQug2pQAo1B09sLqUhWaUZpCpMjCbtReHRbzZKOGpT0Z/R1kerSUN2+HHg+d7FSUPnwWlO/jhC5M7wSiS7MbkkOKt8v+GbIsPh1KhtSiJWSEo/CPBUbDGnyu8zxqvdXDcQBakI86ylZKZCxt2y7pvoZjON1JGRwXJCYk6YzIYbukOh9kR+jzqUDKONp9fIMSrNhhrWt708WonWLmGMvOMrQzFD1xG2fJxK771YgobDN/eaw99SfYR5eRyzjYd25DSqbv 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: List-Subscribe: List-Unsubscribe: On Mon, Apr 28, 2025 at 04:28:16PM +0100, Lorenzo Stoakes wrote: > This is a key step in our being able to abstract and isolate VMA allocation > and destruction logic. > > This function is the last one where vm_area_free() and vm_area_dup() are > directly referenced outside of mmap, so having this in mm allows us to > isolate these. > > We do the same for the nommu version which is substantially simpler. > > We place the declaration for dup_mmap() in mm/internal.h and have > kernel/fork.c import this in order to prevent improper use of this > functionality elsewhere in the kernel. > > While we're here, we remove the useless #ifdef CONFIG_MMU check around > mmap_read_lock_maybe_expand() in mmap.c, mmap.c is compiled only if > CONFIG_MMU is set. > > Signed-off-by: Lorenzo Stoakes Reviewed-by: Kees Cook -- Kees Cook