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Re: RELEASE BLOCKER: Linux doesn't follow x86/x86-64 ABI wrt direction flag
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: "H. Peter Anvin" <hpa at zytor dot com>
- Cc: "Jakub Jelinek" <jakub at redhat dot com>, NightStrike <nightstrike at gmail dot com>, "Olivier Galibert" <galibert at pobox dot com>, "Chris Lattner" <clattner at apple dot com>, "Michael Matz" <matz at suse dot de>, "Richard Guenther" <richard dot guenther at gmail dot com>, "Joe Buck" <Joe dot Buck at synopsys dot com>, "Jan Hubicka" <hubicka at ucw dot cz>, "Aurelien Jarno" <aurelien at aurel32 dot net>, linux-kernel at vger dot kernel dot org, gcc at gcc dot gnu dot org
- Date: Thu, 6 Mar 2008 09:34:35 -0800
- Subject: Re: RELEASE BLOCKER: Linux doesn't follow x86/x86-64 ABI wrt direction flag
- References: <738B72DB-A1D6-43F8-813A-E49688D05771@apple.com> <20080306135139.GA5236@dspnet.fr.eu.org> <b609cb3b0803060737xa0c3c0byb51d51af797eb81f@mail.gmail.com> <6dc9ffc80803060743h502fc96bj6117ef87a8555c3a@mail.gmail.com> <47D012B4.3020104@zytor.com> <20080306162353.GF24887@devserv.devel.redhat.com> <6dc9ffc80803060858i7d4e8b56o99ff8ad301a5cc1a@mail.gmail.com> <47D024AA.9010300@zytor.com> <6dc9ffc80803060914x187049a2hb24ef501baf55601@mail.gmail.com> <47D0271F.4070705@zytor.com>
On Thu, Mar 6, 2008 at 9:17 AM, H. Peter Anvin <hpa@zytor.com> wrote:
> H.J. Lu wrote:
> >>
> >> Not a fix, an (optional) workaround for a system bug.
> >
> > So that is the bug in the Linux kernel. Since fixing kernel is much easier
> > than providing a workaround in compilers, I think kernel should be fixed
> > and no need for icc/gcc fix.
> >
>
> The problem is, you're going to have to be able to produce binaries
> compatible with old kernels for a *long* time for come. Are you
> honestly saying you'll tell those people "use gcc 4.2 or earlier"? If
> so, I think most distros will have to freeze gcc for the next several years.
>
Icc has been following psABI for years on Linux and it doesn't stop people
using icc on Linux. On the other hand, it may be a good idea to provide a
workaround in gcc and enables it by default. OSVs can fix thekernel and
disable it by default.
We can even issue a message whenever the workaround is used.
H.J.