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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37A25C4332F for ; Sun, 8 Sep 2019 16:25:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ED62F214DB for ; Sun, 8 Sep 2019 16:25:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uyaNxu8R" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED62F214DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cyphar.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=TmTiMPxOoFQs0OpIjkmJBHa/CJsI4X5Z+SbINgap2bA=; b=uyaNxu8RTLXb5FGRksRP3NrY/ rr6noZg4njlbRVR47qZRT+7SGSpceJfgm9JSz6qIGgJ4Z2ZjRyDtwg8NDv1cuh7FqZajal0tUSYdV 5ySgQbM3S4oTlNs/0OUECZxczCCEDAbpVUtSdWUhQ+VYoVDk3spTOZHIUOUUEasC7KLT9BxXgjBTj NgSu6ByzG+c/lw3X5dcqJ6el/Mzz40tF0knU9Cki6dOOy3Lo8VNwc5usfbSy2OyR6IU0bxfUI6VRP 2lBIo1mzcJK4Z6erEmKXeBJOWuiJb3IX+Y5rITQFIFHmFaaPwoD6Og80SagR3L/iCdAB2bGn9FyFs eN+7JainQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i6zzm-0004Tw-Sy; Sun, 08 Sep 2019 16:24:58 +0000 Received: from mx2a.mailbox.org ([2001:67c:2050:104:0:2:25:2] helo=mx2.mailbox.org) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i6zzj-0004S9-8b for linux-arm-kernel@lists.infradead.org; Sun, 08 Sep 2019 16:24:57 +0000 Received: from smtp1.mailbox.org (smtp1.mailbox.org [80.241.60.240]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by mx2.mailbox.org (Postfix) with ESMTPS id F270BA10CE; Sun, 8 Sep 2019 18:24:39 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp1.mailbox.org ([80.241.60.240]) by spamfilter04.heinlein-hosting.de (spamfilter04.heinlein-hosting.de [80.241.56.122]) (amavisd-new, port 10030) with ESMTP id RaAVojXx0viX; Sun, 8 Sep 2019 18:24:32 +0200 (CEST) Date: Mon, 9 Sep 2019 02:24:19 +1000 From: Aleksa Sarai To: Jeff Layton Subject: Re: [PATCH v12 11/12] open: openat2(2) syscall Message-ID: <20190908162419.yrzm2s7rflqgdxig@yavin> References: <20190904201933.10736-1-cyphar@cyphar.com> <20190904201933.10736-12-cyphar@cyphar.com> <7236f382d72130f2afbbe8940e72cc67e5c6dce0.camel@kernel.org> MIME-Version: 1.0 In-Reply-To: <7236f382d72130f2afbbe8940e72cc67e5c6dce0.camel@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190908_092455_609750_4238EFDC X-CRM114-Status: GOOD ( 15.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Rasmus Villemoes , Alexei Starovoitov , linux-kernel@vger.kernel.org, David Howells , linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Jiri Olsa , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Tycho Andersen , Aleksa Sarai , Shuah Khan , Alexander Shishkin , Ingo Molnar , linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, Kees Cook , Arnd Bergmann , Jann Horn , linuxppc-dev@lists.ozlabs.org, linux-m68k@lists.linux-m68k.org, Al Viro , Andy Lutomirski , Shuah Khan , Namhyung Kim , David Drysdale , Christian Brauner , "J. Bruce Fields" , linux-parisc@vger.kernel.org, linux-api@vger.kernel.org, Chanho Min , Oleg Nesterov , Eric Biederman , linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds , containers@lists.linux-foundation.org Content-Type: multipart/mixed; boundary="===============4104437893276286960==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============4104437893276286960== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="gzznbyzuni6ynbc5" Content-Disposition: inline --gzznbyzuni6ynbc5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2019-09-07, Jeff Layton wrote: > On Thu, 2019-09-05 at 06:19 +1000, Aleksa Sarai wrote: > > + * @flags: O_* flags. > > + * @mode: O_CREAT/O_TMPFILE file mode. > > + * @upgrade_mask: UPGRADE_* flags (to restrict O_PATH re-opening). > > + * @resolve: RESOLVE_* flags. > > + */ > > +struct open_how { > > + __u32 flags; > > + union { > > + __u16 mode; > > + __u16 upgrade_mask; > > + }; > > + __u16 resolve; > > +}; > > + > > +#define OPEN_HOW_SIZE_VER0 8 /* sizeof first published struct */ > > + >=20 > Hmm, there is no version field. When you want to expand this in the > future, what is the plan? Add a new flag to indicate that it's some > length? The "version number" is the size of the struct. Any extensions we make are appended to the struct (openat2 now takes a size_t argument), and the new copy_struct_{to,from}_user() helpers handle all of the permutations of {old,new} kernel and {old,new} user space. This is how clone3(), sched_[gs]etattr() and perf_event_open() all operate (all of the sigset syscalls operate similarly but don't gracefully handle different kernel vintages -- you just get -EINVAL). --=20 Aleksa Sarai Senior Software Engineer (Containers) SUSE Linux GmbH --gzznbyzuni6ynbc5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQSxZm6dtfE8gxLLfYqdlLljIbnQEgUCXXUrMAAKCRCdlLljIbnQ EgC+AQCVKXVqUiPLaSjLjt+ByWrSsopM/OM3NwCHHZ5oD+CB1gD/cSuQohVmXskg v8dQLpd9K1QW//8GG3Aa/FRHhqPAfAU= =G4Hw -----END PGP SIGNATURE----- --gzznbyzuni6ynbc5-- --===============4104437893276286960== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============4104437893276286960==--