[ANNOUNCEMENT] Updated for 32-bit, new for 64-bit: libsigsegv-2.10-2

Eric Blake eblake@redhat.com
Mon Jul 20 18:19:00 GMT 2015

On 07/18/2015 02:11 PM, Corinna Vinschen wrote:

>> m4 was
>> originally creating an alternate stack of 16k in size, based on a pure
>> guess that it would be large enough (since the headers didn't declare
>> any constant otherwise); but cygwin's sigaltstack() requires an
>> alternate stack of 64k or larger.
> No, 32K (MINSIGSTKSZ) is sufficient.
>> I see a couple of options:
>> 1. see if we can relax cygwin.dll to live with a 16k alternate stack

> So, what about MINSIGSTKSZ == 8192 and SIGSTKSZ == 32768?
> Or MINSIGSTKSZ == 16384 and SIGSTKSZ == 65536?
> That could go into Cygwin 2.2.0 which I could release next week.

I just tested: m4-1.4.17-1 (which uses the 16k alt-stack, compared to
1.4.17-2 using 64k) coupled with the test cygwin 2.2.0-0.1 is once again
able to make use of libsigsegv-2.10-2.  And if I recompile m4 against
cygwin 2.2.0-0.1 headers, I end up with a 32k stack which also works.

That means that so far, I have not found any problems with your new
smaller stack sizing requirements.

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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