From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: [PATCH 1/2] uapi: split openat2(2) definitions from fcntl.h Date: Thu, 19 Dec 2019 12:07:13 +0100 Message-ID: <87a77oy3oe.fsf@oldenburg2.str.redhat.com> References: <20191219105533.12508-1-cyphar@cyphar.com> <20191219105533.12508-2-cyphar@cyphar.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20191219105533.12508-2-cyphar@cyphar.com> (Aleksa Sarai's message of "Thu, 19 Dec 2019 21:55:29 +1100") Sender: linux-kernel-owner@vger.kernel.org To: Aleksa Sarai Cc: Alexander Viro , Jeff Layton , "J. Bruce Fields" , Shuah Khan , David Laight , Christian Brauner , dev@opencontainers.org, containers@lists.linux-foundation.org, libc-alpha@sourceware.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org List-Id: linux-api@vger.kernel.org * Aleksa Sarai: > diff --git a/include/uapi/linux/openat2.h b/include/uapi/linux/openat2.h > new file mode 100644 > index 000000000000..19ef775e8e5e > --- /dev/null > +++ b/include/uapi/linux/openat2.h > @@ -0,0 +1,41 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +#ifndef _UAPI_LINUX_OPENAT2_H > +#define _UAPI_LINUX_OPENAT2_H I think you should include the relevant header for __align_u64 etc. here. [=E2=80=A6] > + * Arguments for how openat2(2) should open the target path. If @resolve= is > + * zero, then openat2(2) operates very similarly to openat(2). > + * > + * However, unlike openat(2), unknown bits in @flags result in -EINVAL r= ather > + * than being silently ignored. @mode must be zero unless one of {O_CREA= T, > + * O_TMPFILE} are set. > + * > + * @flags: O_* flags. > + * @mode: O_CREAT/O_TMPFILE file mode. > + * @resolve: RESOLVE_* flags. > + */ > +struct open_how { > + __aligned_u64 flags; > + __u16 mode; > + __u16 __padding[3]; /* must be zeroed */ > + __aligned_u64 resolve; > +}; > + > +#define OPEN_HOW_SIZE_VER0 24 /* sizeof first published struct */ > +#define OPEN_HOW_SIZE_LATEST OPEN_HOW_SIZE_VER0 Are these really useful for the UAPI header? Is there a situation where OPEN_HOW_SIZE_LATEST would be different from sizeof (struct open_how)? The header is not compatible with the assembler anyway, so the numeric constant does not seem useful. Thanks, Florian