[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA
From: |
Eric Blake |
Subject: |
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA |
Date: |
Mon, 20 Jun 2011 11:54:16 -0600 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc14 Lightning/1.0b3pre Mnenhy/0.8.3 Thunderbird/3.1.10 |
[adding bug-gnulib]
On 06/19/2011 11:35 PM, Paul Eggert wrote:
> On 06/19/11 12:01, Andy Wingo wrote:
>> No, this program also exhibits the same incorrect behavior, for purposes
>> of stack growth checking.
>
> Thanks, I guess we'll have to turn it up a notch. How about the
> following test program?
>
> int
> find_stack_direction (int *addr, int depth)
> {
> int dir, dummy = 0;
> if (! addr)
> addr = &dummy;
> *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1;
> dir = depth ? find_stack_direction (addr, depth - 1) : 0;
> return dir + dummy;
> }
>
> int
> main (int argc, char **argv)
> {
> return find_stack_direction (0, argc + !argv + 20) < 0;
> }
>
>
> This program is reflected in my most recent patch, here:
>
> http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497
Hmm, we'll need to backport this improved stack-direction testing to
gnulib and libsigsegv, then, since your previous autoconf patch (which
has been defeated by newer gcc optimization) was lifted from gnulib's
c-stack stack-direction probe.
--
Eric Blake address@hidden +1-801-349-2682
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
- Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, (continued)
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Paul Eggert, 2011/06/18
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Andy Wingo, 2011/06/20
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA,
Eric Blake <=
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Paul Eggert, 2011/06/20
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Ralf Wildenhues, 2011/06/21
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Paul Eggert, 2011/06/21
Re: bug in check for stack growth direction in _AC_LIBOBJ_ALLOCA, Eric Blake, 2011/06/20