From mboxrd@z Thu Jan 1 00:00:00 1970 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 B13A137F for ; Sat, 26 Aug 2023 00:54:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 761E1C433C8; Sat, 26 Aug 2023 00:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693011289; bh=KunlMoFaeB09wWpK/chJYbgKS5tfp+/UPw8r6E8VtDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FSgNX7cYWf2qXdMFCXD0W7Ors9olo5dw9e/ubec5mBKB8+DJR3PCWeflqAWBrUYb0 X2o1UjfBWV5qTqbf0R8Lyfjk7WbHr6/e9tZbXrkfFpeHMJIEbFRzSPg/1k6AtNDdPQ sZjVeIQtT4GkUioINsligfhNom5WIP9u9+YfPIfsmYXUjEyvo2EUYYVv3xuLnNyk21 hgqTssuXFfgYZNLh61C4bGjExZxsLv6euZ2K/V3DTMdq5nJlvnxrW1MfQtt3V59Tf6 k+j1ErQANSDNyg6LyJNEEX4Nd5fsU4uYXW/KhjIVrr6PExmaSUoyfC1xPXi15w2pPR P/ZFZ5u2L4xiQ== From: SeongJae Park To: Kees Cook Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qing Zhao , linux-hardening@vger.kernel.org Subject: Re: [RFC PATCH] mm/damon/sysfs: add __counted_by() annotation Date: Sat, 26 Aug 2023 00:54:47 +0000 Message-Id: <20230826005447.109776-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <202308251426.94092475C3@keescook> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Kees, On Fri, 25 Aug 2023 14:32:34 -0700 Kees Cook wrote: > On Fri, Aug 25, 2023 at 02:04:41AM +0000, SeongJae Park wrote: > > Commit dd06e72e68bc ("Compiler Attributes: Add __counted_by macro") > > added __counted_by() annotation. The underlying attribute for the > > feature is still under development, but adopting it can improve the > > readability of the code. Apply it to four dynamic arrays in DAMON sysfs > > code. > > > > Signed-off-by: SeongJae Park > > --- > > mm/damon/sysfs.c | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c > > index 808a8efe0523..36a176f38726 100644 > > --- a/mm/damon/sysfs.c > > +++ b/mm/damon/sysfs.c > > @@ -93,7 +93,7 @@ static const struct kobj_type damon_sysfs_region_ktype = { > > > > struct damon_sysfs_regions { > > struct kobject kobj; > > - struct damon_sysfs_region **regions_arr; > > + struct damon_sysfs_region **regions_arr __counted_by(nr); > > int nr; > > }; > > Unfortunately this isn't supported yet for non-flexible-array-members: > > mm/damon/sysfs.c:96:14: error: 'counted_by' attribute may not be specified for a non-array field > 96 | struct damon_sysfs_region **regions_arr __counted_by(nr); > | ^~~~~ > > We'll have to wait a bit before we can add this patch. Thank you for checking this and let me know. Ok, I will wait. > Thank you for > getting it ready, though! Owing to your previous contributions. Thank you for helping me make DAMON code better to read :) > This support is next in line. :) > > The FAM support is likely ready to land, though[1]. I just tested it > today. > > -Kees > > [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/628459.html > > -- > Kees Cook > Thanks, SJ