From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulrich Drepper Subject: Re: 64-syscall args on 32-bit vs syscall() Date: Wed, 17 Mar 2010 02:14:05 -0700 Message-ID: <4BA09D5D.5090602@redhat.com> References: <20100315134449.GB1653@linux-mips.org> <4B9E4EB1.9010800@zytor.com> <4B9E59B7.6060405@redhat.com> <20100315.120004.209998642.davem@davemloft.net> <4B9E8D67.8040209@zytor.com> <1268685311.2335.38.camel@pasglop> <1268776570.19726.98.camel@spokane1.rchland.ibm.com> <1268785874.2335.137.camel@pasglop> <4BA06E1B.2040706@redhat.com> <1268816179.2335.187.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx1.redhat.com ([209.132.183.28]:14283 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753539Ab0CQJOa (ORCPT ); Wed, 17 Mar 2010 05:14:30 -0400 In-Reply-To: <1268816179.2335.187.camel@pasglop> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt Cc: munroesj@us.ibm.com, "H. Peter Anvin" , David Miller , ralf@linux-mips.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@teksavvy.com, torvalds@linux-foundation.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 03/17/2010 01:56 AM, Benjamin Herrenschmidt wrote: >> - You keep the existing syscall() exported by glibc for binary >> compatibility >=20 >> - You add a new __syscall() (or whatever you want to name it) that = adds >> a dummy argument at the beginning, and whose implementation shifts >> everything by 2 instead of 1 argument before calling into the kernel >=20 >> - You define in unistd.h or whatever is relevant, a macro that does= : >=20 >> #define syscall(__sysno, __args..) __syscall(0, _sysno, __args) >=20 >> I believe that should cover it, at least for powerpc, possibly for o= ther >> archs too though as I said, I may have missed something there. How can this possibly be the case? This will screw people who currentl= y work around the ppc limitations of the existing syscall. Just leave it alone. - --=20 =E2=9E=A7 Ulrich Drepper =E2=9E=A7 Red Hat, Inc. =E2=9E=A7 444 Castro S= t =E2=9E=A7 Mountain View, CA =E2=9D=96 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/ iEYEARECAAYFAkugnV0ACgkQ2ijCOnn/RHRL4gCeIY0SLDCgLqtVvuMw+pvCzkwE 3MIAoJQRK5Mc+WtC/Wz9tPFPy4X+EALe =3Dlexw -----END PGP SIGNATURE-----