From: Xiaoming Ni <nixiaoming@huawei.com>
To: Peter Xu <peterx@redhat.com>
Cc: <aarcange@redhat.com>, <akpm@linux-foundation.org>,
<cracauer@cons.org>, <dplotnikov@virtuozzo.com>,
<gokhale2@llnl.gov>, <hannes@cmpxchg.org>, <hughd@google.com>,
<jglisse@redhat.com>, <kirill@shutemov.name>,
<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<maxime.coquelin@redhat.com>, <mcfadden8@llnl.gov>,
<mcgrof@kernel.org>, <mgorman@suse.de>, <mike.kravetz@oracle.com>,
<pbonzini@redhat.com>, <rppt@linux.vnet.ibm.com>,
<xemul@virtuozzo.com>, <keescook@chromium.org>
Subject: Re: [PATCH v2 1/1] userfaultfd/sysctl: add vm.unprivileged_userfaultfd
Date: Thu, 28 May 2020 16:50:49 +0800 [thread overview]
Message-ID: <a5aa7dfd-b4a9-0ab2-9392-d7889897382f@huawei.com> (raw)
In-Reply-To: <20200527142143.GC1194141@xz-x1>
On 2020/5/27 22:21, Peter Xu wrote:
> On Wed, May 27, 2020 at 02:54:13PM +0800, Xiaoming Ni wrote:
>>
>> On Tue, Mar 19, 2019 at 11:07:22AM +0800, Peter Xu wrote:
>>> Add a global sysctl knob "vm.unprivileged_userfaultfd" to control
>>> whether userfaultfd is allowed by unprivileged users. When this is
>>> set to zero, only privileged users (root user, or users with the
>>> CAP_SYS_PTRACE capability) will be able to use the userfaultfd
>>> syscalls.
>>
>> Hello
>
> Hi, Xiaoming,
>
>> I am a bit confused about this patch, can you help to answer it.
>>
>> Why the sysctl interface of fs/userfaultfd.c belongs to vm_table instead of
>> fs_table ?
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cefdca0a86be517bc390fc4541e3674b8e7803b0
>
> Because I think it makes more sense to put the new key into where it suites
> better, irrelevant to which directory the variable is declared. To me,
> unprivileged_userfaultfd is definitely more suitable for vm rather than fs,
> because userfaultfd is really about memory management rather than file system.
>
> Thanks,
>
Thank you for your answer
Since userfaultfd and vm are more closely related, will there be
consideration to move fs/userfaultfd.c to the mm directory in the future?
Thanks
Xiaoming Ni
next prev parent reply other threads:[~2020-05-28 8:50 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 6:54 [PATCH v2 1/1] userfaultfd/sysctl: add vm.unprivileged_userfaultfd Xiaoming Ni
2020-05-27 14:21 ` Peter Xu
2020-05-28 8:50 ` Xiaoming Ni [this message]
2020-05-28 12:49 ` Peter Xu
-- strict thread matches above, loose matches on Subject: below --
2019-03-19 3:07 [PATCH v2 0/1] userfaultfd: allow to forbid unprivileged users Peter Xu
2019-03-19 3:07 ` [PATCH v2 1/1] userfaultfd/sysctl: add vm.unprivileged_userfaultfd Peter Xu
2019-03-19 7:11 ` Mike Rapoport
2019-03-19 18:07 ` Andrea Arcangeli
2019-03-19 18:02 ` Andrew Morton
2019-03-19 18:28 ` Dr. David Alan Gilbert
2019-03-20 0:20 ` Peter Xu
2019-03-20 19:01 ` Andrea Arcangeli
2019-03-21 13:43 ` Luis Chamberlain
2019-03-21 21:06 ` Andrea Arcangeli
2019-04-23 22:19 ` Kees Cook
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