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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: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: kcgzjca86ntxussdwrw7kapbtgqwpsf7 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: A0AA5140019 X-Rspam-User: X-HE-Tag: 1693011290-439640 X-HE-Meta: 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 B4Snh66F 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 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: 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