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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 26 Apr 2022 19:13:47 +0200
Message-ID: <CAK8P3a0th99KbPO_Mt17uztHay6vBMngT-ii2dFW4++BaAQNpw@mail.gmail.com>
Subject: Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained
 access control
To:     Axel Rasmussen <axelrasmussen@google.com>
Cc:     "Dmitry V. Levin" <ldv@altlinux.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Charan Teja Reddy <charante@codeaurora.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>,
        Hugh Dickins <hughd@google.com>, Jan Kara <jack@suse.cz>,
        Jonathan Corbet <corbet@lwn.net>,
        Mel Gorman <mgorman@techsingularity.net>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@kernel.org>, Nadav Amit <namit@vmware.com>,
        Peter Xu <peterx@redhat.com>, Shuah Khan <shuah@kernel.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        zhangyi <yi.zhang@huawei.com>,
        Linux API <linux-api@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
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On Tue, Apr 26, 2022 at 6:00 PM Axel Rasmussen <axelrasmussen@google.com> wrote:
>
> You're right, [1] says _IO is appropriate for ioctls which only take
> an integer argument. I'll send a v3 with this fix, although I might
> wait a bit for any other review comments before doing so. Thanks for
> taking a look!

If there are no other command codes, you could also set .compat_ioctl
to the same function pointer as .unlocked_ioctl, the compat_ptr_ioctl
conversion is only needed when there are commands that take a pointer.

        Armd