From nobody Tue Dec 16 05:46:58 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 4ED36224B04 for ; Thu, 6 Feb 2025 06:15:23 +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=1738822524; cv=none; b=ITL9nRHKZ7auf4xAApAJgghyFc2yhISUWktIw/DAF2JRs2IM/ujdll5JEaeCM3fEKCy8CikNbwistWgXBjx35oYnYGKYM1ZPvG83snahVQbFfKc7RMDanvB4+NBMxjQ/YxDzwANsDI10rYA+Ma2KbEUjvu2k55TrYjeXdYT6AJA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738822524; c=relaxed/simple; bh=mfBMQDGwCijsuSEaM5RCGlWQCxDRxNtkNxhQORCqX0Y=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ECys4QKAwbePByAcUfhiBTg5oLK0XTrsriP5EP1AifhpfrYgQyd34HuQEOIM0I+uviXslqmlb95Hp0HFbp7Z9lVtSA+gW6z7jqLQ1Q5NEHesS0Zj9OXenr0ZHam6/GdrE5/ahXzle8ALKyMGB1Bqb6VOJgKFMWesHJvWwvwlNOU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E1xkWOmc; 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="E1xkWOmc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BACD7C4CEE5; Thu, 6 Feb 2025 06:15:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738822523; bh=mfBMQDGwCijsuSEaM5RCGlWQCxDRxNtkNxhQORCqX0Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E1xkWOmctRFfUviRHAuoF/YWqqtLhCLSeVJMBCIZ5GOfqX1Em3z6RE1AsxPdoFvDD DcmtmDzLgBMTvvl9UJA+Jpmt30YKmA5ghNeJS2A6DqzlEe5dDoE7SVFsK1znh2SXXT m8kJckllh6o8rTjHTiWiWPNXY3TwvPqqeRkdlvE+X0eUk1rxbmFdJZ0d7CXqty/uXB 5vk5WFGbcI9uK2h/3oAZu064VNDhZGcd6TYV76rphB8u6smNhIJBi6Npo6PCYlWj02 1vcsPrkLrYI7Gp5UPuIGgBGedOPuWnhC4dxe6EWSGe+Gxxj6S3PhBWLyYVz4sV36CU 2vGrcVjrwY5IA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Davidlohr Bueso , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/4] mm/madvise: split out madvise input validity check Date: Wed, 5 Feb 2025 22:15:15 -0800 Message-Id: <20250206061517.2958-3-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250206061517.2958-1-sj@kernel.org> References: <20250206061517.2958-1-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. Reviewed-by: Shakeel Butt Reviewed-by: Lorenzo Stoakes Reviewed-by: Davidlohr Bueso Signed-off-by: SeongJae Park Reviewed-by: Liam R. Howlett --- mm/madvise.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index df5a87a1846a..efab2878be7c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1594,6 +1594,27 @@ 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. * @@ -1673,20 +1694,11 @@ 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