This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: glibc 2.21 - Machine maintainers, please test your machines.
- From: Torvald Riegel <triegel at redhat dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Andreas Schwab <schwab at suse dot de>, Chris Metcalf <cmetcalf at ezchip dot com>, "Carlos O'Donell" <carlos at redhat dot com>, GNU C Library <libc-alpha at sourceware dot org>, David Miller <davem at davemloft dot net>, Richard Henderson <rth at redhat dot com>, Mike Frysinger <vapier at gentoo dot org>, "Joseph S. Myers" <joseph at codesourcery dot com>, Kaz Kojima <kkojima at rr dot iij4u dot or dot jp>, Thomas Schwinge <thomas at codesourcery dot com>, Marcus Shawcroft <marcus dot shawcroft at linaro dot org>, Chung-Lin Tang <chunglin_tang at mentor dot com>, Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>, Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- Date: Mon, 26 Jan 2015 14:51:54 +0100
- Subject: Re: glibc 2.21 - Machine maintainers, please test your machines.
- Authentication-results: sourceware.org; auth=none
- References: <54C2BDD7 dot 7000304 at redhat dot com> <54C3B6D5 dot 3090308 at ezchip dot com> <1422119595 dot 29655 dot 42 dot camel at triegel dot csb> <54C5094A dot 8060300 at ezchip dot com> <54C51D94 dot 6030007 at ezchip dot com> <CAMe9rOpOuuC_Bf1eHs9iaiUY6V-fVMHUCKZPAwje_NemBy84wA at mail dot gmail dot com> <20150125215150 dot GA15033 at gmail dot com> <54C569E5 dot 9050305 at ezchip dot com> <CAMe9rOrundPWENuw-Ne=pW6706Rc9RLpkw7Zx859M9G1JRFk0A at mail dot gmail dot com> <mvmd261rj1p dot fsf at hawking dot suse dot de> <CAMe9rOotZWCHsp4Wizrk4_i+-CWVVxjrRy9n_9_sF7yuW9TyiQ at mail dot gmail dot com> <mvmlhkpps9f dot fsf at hawking dot suse dot de> <CAMe9rOoKMiLm1sUmQYFEkkO=SRTPqZkmHuBh7_4jLqFADTcZbA at mail dot gmail dot com>
On Mon, 2015-01-26 at 05:50 -0800, H.J. Lu wrote:
> On Mon, Jan 26, 2015 at 5:48 AM, Andreas Schwab <schwab@suse.de> wrote:
> > "H.J. Lu" <hjl.tools@gmail.com> writes:
> >
> >> On Mon, Jan 26, 2015 at 1:24 AM, Andreas Schwab <schwab@suse.de> wrote:
> >>> "H.J. Lu" <hjl.tools@gmail.com> writes:
> >>>
> >>>> It doesn't change the size, only increases alignment from 4 bytes to 8 bytes.
> >>>
> >>> Alignment is part of the ABI.
> >>>
> >>
> >> For x32, we can increase alignment from 4 bytes to 8 bytes without breaking
> >> existing binaries.
> >
> > The compiler may generate code to take advantage of the bigger
> > alignment, which will fail if not fulfilled (this is not just about
> > unaligned accesses).
> >
>
> Failure shouldn't happen on x32 in this case.
>
Then please provide a *detailed* comment why this is the case along with
the alignment change in x86 semaphore.h. Given that we're discussing
whether this is safe or not, I think we should have detailed
documentation. And this will also help conclude the discussion.
- References:
- glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.
- Re: glibc 2.21 - Machine maintainers, please test your machines.