From nobody Tue Dec 16 07:08:44 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C6902D530 for ; Fri, 17 Jan 2025 01:31:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737077468; cv=none; b=su7Pzrq0r9EgNvVU+3YwyocqHItXBB1Gbn/7t3s6cSlT1++G4SxgW6ye/ER4TdcqxyrXEORVDwuMosb7SLIacjXId/0UEnGSvmNKgIUbp3ePipfTAvmuMqQsevDRlvUKD3v3ATVRAWlI+Sc0J6xji7fpIBBfFCavXU7TZijWH+U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737077468; c=relaxed/simple; bh=DjxKujI4JGXMt2ixtDL0O5/UiHpIa+TfTVLg8eL2qoo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=m52/zvHfyq5qkpqxibZ7qjhNOT7H9wsEnftxhOeQPbNYC4fO1pdA1Uc9RmYcjI3Io6ZFUoGfdPusuUFcQLVCHnYglk7qHyodYWZi14TUfJ3IjWpURLxekikJ9O0C1HRZIfcc+siq3JxwPLntRmNE50aitvsbIwDYnusI1EqLFmg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qN8HbqYN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qN8HbqYN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 287E3C4CEE1; Fri, 17 Jan 2025 01:31:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737077468; bh=DjxKujI4JGXMt2ixtDL0O5/UiHpIa+TfTVLg8eL2qoo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qN8HbqYNv+0BPFVp7MR/Cln6d72dSLPk4HTE+KFIH1uUdIH632Yk5mBAOWx6ZC3o2 hBlyt4o+gP3uJHBnhLeCvC+GxEOgdlwWaB8a44jYRBCgaMgT3l3ElZ1iszVtpY00gz jrwBxDxUNo9160DThKvjn3nrldDSGMf5Bzpw/N2cciwv7ohZCdCvV9Vn8V6TYPQOpv FsEkq4FDBdLzpJfq40a1+h0KJ4qoXzxXZBFDBG1vnhKtKPKfIM/tW+rxgMwNl0SuZj 7Qac9aAKUD/p3mV6mOu2HJNOezPm7HSBIr3f1HQmoDUuhIkQgswLsS8PNeXiwgErF6 VT1m8GqIhSSyQ== From: SeongJae Park To: Cc: SeongJae Park , "Liam R. Howlett" , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v2 2/4] mm/madvise: split out madvise input validity check Date: Thu, 16 Jan 2025 17:30:56 -0800 Message-Id: <20250117013058.1843-3-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250117013058.1843-1-sj@kernel.org> References: <20250117013058.1843-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Split out the madvise parameters validation logic from do_madvise(), for easy reuse of the logic from a future change. Signed-off-by: SeongJae Park Reviewed-by: Davidlohr Bueso Reviewed-by: Lorenzo Stoakes Reviewed-by: Shakeel Butt --- mm/madvise.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index ae0964bc4d88..9cc31efe875a 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1592,6 +1592,27 @@ static void madvise_unlock(struct mm_struct *mm, int= behavior) mmap_read_unlock(mm); } =20 +static bool is_valid_madvise(unsigned long start, size_t len_in, int behav= ior) +{ + size_t len; + + if (!madvise_behavior_valid(behavior)) + return false; + + if (!PAGE_ALIGNED(start)) + return false; + len =3D PAGE_ALIGN(len_in); + + /* Check to see whether len was rounded up from small -ve to zero */ + if (len_in && !len) + return false; + + if (start + len < start) + return false; + + return true; +} + /* * The madvise(2) system call. * @@ -1671,20 +1692,11 @@ int do_madvise(struct mm_struct *mm, unsigned long = start, size_t len_in, int beh size_t len; struct blk_plug plug; =20 - if (!madvise_behavior_valid(behavior)) + if (!is_valid_madvise(start, len_in, behavior)) return -EINVAL; =20 - if (!PAGE_ALIGNED(start)) - return -EINVAL; len =3D PAGE_ALIGN(len_in); - - /* Check to see whether len was rounded up from small -ve to zero */ - if (len_in && !len) - return -EINVAL; - end =3D start + len; - if (end < start) - return -EINVAL; =20 if (end =3D=3D start) return 0; --=20 2.39.5