linux-kernel - Re: [RFC] make kmemleak scan __ro_after_init section (was: Re: [PATCH 0/5] genetlink improvements)

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Date:   Wed, 2 Nov 2016 22:40:17 -0700
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Jakub Kicinski <kubakici@...pl>
Cc:     Johannes Berg <johannes@...solutions.net>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Catalin Marinas <catalin.marinas@....com>, linux-mm@...ck.org
Subject: Re: [RFC] make kmemleak scan __ro_after_init section (was: Re: [PATCH
 0/5] genetlink improvements)

On Wed, Nov 2, 2016 at 4:47 PM, Jakub Kicinski <kubakici@...pl> wrote:
>
> Thanks for looking into this!  Bisect led me to the following commit:
>
> commit 56989f6d8568c21257dcec0f5e644d5570ba3281
> Author: Johannes Berg <johannes.berg@...el.com>
> Date:   Mon Oct 24 14:40:05 2016 +0200
>
>     genetlink: mark families as __ro_after_init
>
>     Now genl_register_family() is the only thing (other than the
>     users themselves, perhaps, but I didn't find any doing that)
>     writing to the family struct.
>
>     In all families that I found, genl_register_family() is only
>     called from __init functions (some indirectly, in which case
>     I've add __init annotations to clarifly things), so all can
>     actually be marked __ro_after_init.
>
>     This protects the data structure from accidental corruption.
>
>     Signed-off-by: Johannes Berg <johannes.berg@...el.com>
>     Signed-off-by: David S. Miller <davem@...emloft.net>
>
>
> I realized that kmemleak is not scanning the __ro_after_init section...
> Following patch solves the false positives but I wonder if it's the
> right/acceptable solution.

Nice work! Looks reasonable to me, but I am definitely not familiar
with kmemleak. ;)