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Date:   Mon, 15 Jun 2020 11:08:33 -0700
From:   Kees Cook <keescook@chromium.org>
To:     "Reshetova, Elena" <elena.reshetova@intel.com>
Cc:     Xiaoming Ni <nixiaoming@huawei.com>,
        Peter Zijlstra <peterz@infradead.org>,
        David Windsor <dwindsor@gmail.com>,
        Hans Liljestrand <ishkamiel@gmail.com>,
        Paul Moore <paul@paul-moore.com>,
        "edumazet@google.com" <edumazet@google.com>,
        "paulmck@kernel.org" <paulmck@kernel.org>,
        David Howells <dhowells@redhat.com>,
        "shakeelb@google.com" <shakeelb@google.com>,
        James Morris <jamorris@linux.microsoft.com>,
        "alex.huangjianhui@huawei.com" <alex.huangjianhui@huawei.com>,
        "dylix.dailei@huawei.com" <dylix.dailei@huawei.com>,
        "chenzefeng2@huawei.com" <chenzefeng2@huawei.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/3] Convert nsproxy, groups, and creds to refcount_t
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On Mon, Jun 15, 2020 at 05:35:58AM +0000, Reshetova, Elena wrote:
> > On Mon, Jun 15, 2020 at 10:10:08AM +0800, Xiaoming Ni wrote:
> > > On 2020/6/13 2:34, Kees Cook wrote:
> > > > This series was never applied[1], and was recently pointed out as
> > > > missing[2]. If someone has a tree for this, please take it. Otherwise,
> > > > please Ack and I'll send it to Linus.
> > > >
> > > > Thanks!
> > > >
> > > > -Kees
> > > >
> > > > [1] https://lore.kernel.org/lkml/20190306110549.7628-1-
> > elena.reshetova@intel.com/
> > > > [2] https://lore.kernel.org/lkml/1591957695-118312-1-git-send-email-
> > nixiaoming@huawei.com/
> > > >
> > > > Elena Reshetova (3):
> > > >    nsproxy: convert nsproxy.count to refcount_t
> > > >    groups: convert group_info.usage to refcount_t
> > > >    creds: convert cred.usage to refcount_t
> > > >
> > > >   include/linux/cred.h    | 15 +++++++-------
> > > >   include/linux/nsproxy.h |  7 +++----
> > > >   kernel/cred.c           | 44 ++++++++++++++++++++---------------------
> > > >   kernel/groups.c         |  2 +-
> > > >   kernel/nsproxy.c        |  6 +++---
> > > >   net/sunrpc/auth.c       |  2 +-
> > > >   6 files changed, 38 insertions(+), 38 deletions(-)
> > > >
> > >
> > > Should mm->mm_users also be replaced by refcount_t?
> > 
> > I'll say "yes". :)
> > https://lore.kernel.org/lkml/1487671124-11188-1-git-send-email-
> > elena.reshetova@intel.com/
> > 
> > > In addition, is it better to change all variables that use
> > > atomic_dec_and_test to control the release process to refconut_t?
> > 
> > For the most part, yes. The following may find a lot of them:
> > scripts/coccinelle/api/atomic_as_refcounter.cocci
> > 
> > If you can go through that and double check for prior series from Elena,
> > we can get through all the rest of them.
> 
> I have these ones also here in case anyone is interested:
> https://github.com/ereshetova/linux-stable/commits/refcount_t_fs
> https://github.com/ereshetova/linux-stable/commits/refcount_t_block
> 
> They haven't been rebased for a while, but if there is an interest, 
> I can certainly do it.

That would be great; yes!

-- 
Kees Cook