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Date:   Mon, 25 Apr 2022 23:32:49 +0300
From:   "Dmitry V. Levin" <ldv@altlinux.org>
To:     Axel Rasmussen <axelrasmussen@google.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
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Subject: Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine
 grained access control
Message-ID: <20220425203249.GA5814@altlinux.org>
References: <20220422212945.2227722-1-axelrasmussen@google.com>
 <20220422212945.2227722-3-axelrasmussen@google.com>
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On Fri, Apr 22, 2022 at 02:29:41PM -0700, Axel Rasmussen wrote:
[...]
> --- a/include/uapi/linux/userfaultfd.h
> +++ b/include/uapi/linux/userfaultfd.h
> @@ -12,6 +12,10 @@
>  
>  #include <linux/types.h>
>  
> +/* ioctls for /dev/userfaultfd */
> +#define USERFAULTFD_IOC 0xAA
> +#define USERFAULTFD_IOC_NEW _IOWR(USERFAULTFD_IOC, 0x00, int)

Why this new ioctl is defined using _IOWR()?  Since it neither reads from
user memory nor writes into user memory, it should rather be defined using
_IO(), shouldn't it?


-- 
ldv