From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A69B9C433F5 for ; Tue, 26 Apr 2022 16:01:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 36E7E6B0073; Tue, 26 Apr 2022 12:01:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 31DB36B0074; Tue, 26 Apr 2022 12:01:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1979E6B0075; Tue, 26 Apr 2022 12:01:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 0634E6B0073 for ; Tue, 26 Apr 2022 12:01:04 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id C605126729 for ; Tue, 26 Apr 2022 16:01:03 +0000 (UTC) X-FDA: 79399494006.16.FC5D7A6 Received: from mail-io1-f49.google.com (mail-io1-f49.google.com [209.85.166.49]) by imf18.hostedemail.com (Postfix) with ESMTP id 182401C004B for ; Tue, 26 Apr 2022 16:00:58 +0000 (UTC) Received: by mail-io1-f49.google.com with SMTP id e194so20505983iof.11 for ; Tue, 26 Apr 2022 09:01:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=dyCNcdxP+OP+ZEEDkKpS4dIut/dFXRkxuAQItAbC2hk=; b=kkI2HO5/ZEBb6dwCosEFba8Hqs93phXW7y7LQIwDiDweskbxzWfkhJOxUXgbksafGv Cj9I3+VUsMtqzbQ+FRheYG7Jnp0nCQoqCtylg9A9uVvjFZFE+gYUol4vZnJS8L/D7fcH IXLA9h7oaFPNuHm4FrQjgkuQGxMTT+zn4y0Dc3ZUaMQ6grfstTlV1uURhTu7yZhAB2CR S15Az/6PGwq5RzEtyE76iZSrukPtIepHVy15uTIKCKRfoQGMqwl6nQ2Wcrtywgqq4l9K yrTT7rEccOM0wyFm2LgURZQ9atXRmAewK37yNCUoS/4n8PFFGhjVqFY7J9psP2v3Z2G9 KjGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=dyCNcdxP+OP+ZEEDkKpS4dIut/dFXRkxuAQItAbC2hk=; b=MYJXss2HMcphSSUesDJ17kJ36TYiQDpwETLcnO02znQ+c1vF5F6GfN+mxN3quBAirC XSzfH5ld8gJVo+lmDPdLQxvp6UOclehRdWLWjIN37HFdWPzEwzPu4GkUxqHVEcCqyDtb XrcbR7ZHQ5Uxh9g8rA79IMlV2QLwRSrs8U05fDYwKwMWqTmogrpQDaeUKjfcohn43K72 +ha0GnRnT45WWNRhJxtNqzL8HZKHHY+5WxzkPf4Pf17J2tUAMTOlA4aXFpOmu0OEsBug xvm3j727ekLHCaW3lZ6DIc/+pCq3Lb9vn2jsNTVtwMOoWuNu6Ng7J30MM/PjlSk8M8uR MuSw== X-Gm-Message-State: AOAM532FZwsLuqQkwgORU12Vq2JfaW/KQkQUm06Fs1iQvRvjuPbSUttx 4JOQToyoKoSHDlYdSz1NH5cnYxuHNktob0wueFUlGA== X-Google-Smtp-Source: ABdhPJy2p2YsSAWaLRUyeCx9GIenmVZnYXSr1zBWwbH2S+IZQF4NN6DuvWqwwrbZ5neEqlH8OPqJygq6V4YSc9feqz0= X-Received: by 2002:a05:6638:1695:b0:32a:a178:98bc with SMTP id f21-20020a056638169500b0032aa17898bcmr10205311jat.167.1650988862310; Tue, 26 Apr 2022 09:01:02 -0700 (PDT) MIME-Version: 1.0 References: <20220422212945.2227722-1-axelrasmussen@google.com> <20220422212945.2227722-3-axelrasmussen@google.com> <20220425203249.GA5814@altlinux.org> In-Reply-To: <20220425203249.GA5814@altlinux.org> From: Axel Rasmussen Date: Tue, 26 Apr 2022 09:00:26 -0700 Message-ID: Subject: Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control To: "Dmitry V. Levin" Cc: Alexander Viro , Andrew Morton , Charan Teja Reddy , Dave Hansen , Gleb Fotengauer-Malinovskiy , Hugh Dickins , Jan Kara , Jonathan Corbet , Mel Gorman , Mike Kravetz , Mike Rapoport , Nadav Amit , Peter Xu , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , zhangyi , linux-api@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, LKML , Linux MM , Linuxkselftest Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 182401C004B X-Stat-Signature: sc79rimxjgch89uzoj9mmje3z7yoywpc Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="kkI2HO5/"; spf=pass (imf18.hostedemail.com: domain of axelrasmussen@google.com designates 209.85.166.49 as permitted sender) smtp.mailfrom=axelrasmussen@google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1650988858-576462 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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! https://www.kernel.org/doc/html/latest/driver-api/ioctl.html On Mon, Apr 25, 2022 at 1:32 PM Dmitry V. Levin wrote: > > 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 > > > > +/* 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