[Debian-science-sagemath] cypari2 hangs on ppc64el when pari stack overflows

Jerome BENOIT calculus at rezozer.net
Sat Oct 6 11:30:22 BST 2018



On 06/10/18 14:17, Jerome BENOIT wrote:
> Hello,
> 
> On 06/10/18 13:36, Tobias Hansen wrote:
>> Hi,
>>
>> sagemath 8.3 currently fails to build on ppc64el due to a test that triggers a pari stack overflow sometimes hanging indefinitely. The bug can be triggered by the following Python code:
>>
>> import cypari2
>> pari = cypari2.Pari()
>> pari.allocatemem(200000)
>> pari('x^2 + 10^100 + 1').nfinit()
>>
>> The last line sometimes hangs indefinitely on ppc64el instead of throwing an error. When running the equivalent code directly in gp (here one needs a smaller stack size to trigger the overflow)
>>
>> allocatemem(50000)
>> p = x^2 + 10^100 + 1
>> nfinit(p)
>>
>> it throws the error as on other architectures. So I think the bug should be in cysignals or cypari2. Before reporting this (which will maybe not help much since people usually don't have access to this architecture) it would be good to test with the latest version of cysignals (we still have 1.6.7). What's the status of getting that packaged?
> 
> I am working on cysignals:
> the a upstream set-up machinery was changed (and badly). I have my idea on how to fix it.
> But I need time before me. I may have time at the hand of the month to  focus on it.

Is the issue the one reported here: https://launchpad.net/ubuntu/+source/cysignals/1.6.7+ds-4ubuntu1

Jerome

> 
> Sorry for that.
> 
> Jerome
> 
>>
>> Best,
>>
>> Tobias
>>
>>
>>
>> _______________________________________________
>> Debian-science-sagemath mailing list
>> Debian-science-sagemath at alioth-lists.debian.net
>> https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/debian-science-sagemath
>>
> 
> 
> 
> _______________________________________________
> Debian-science-sagemath mailing list
> Debian-science-sagemath at alioth-lists.debian.net
> https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/debian-science-sagemath
> 

-- 
Jerome BENOIT | calculus+at-rezozer^dot*net
https://qa.debian.org/developer.php?login=calculus@rezozer.net
AE28 AE15 710D FF1D 87E5  A762 3F92 19A6 7F36 C68B

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 1528 bytes
Desc: OpenPGP digital signature
URL: <http://alioth-lists.debian.net/pipermail/debian-science-sagemath/attachments/20181006/e561d908/attachment.sig>


More information about the Debian-science-sagemath mailing list