Re: [RFC] powerpc: restore TOC when static longjmp to shared object

[Rogerio Alves <rcardoso@linux.vnet.ibm.com>]

Em 23-05-2018 11:24, Alexander Monakov escreveu:
> On Wed, 23 May 2018, Rogerio Alves wrote:
>> I don't think that alloca/memset should destroy the caller stack like is
>> happening but, also I think we have to restore TOC to the caller frame after
>> the longjmp in that case also. I don't know if there's any other more direct
>> and robust ways to checking if TOC is correctly restored. I can't think in
>> anything easier than always restore.
> 
> I'm not challenging the idea that "always restoring" is an appropriate fix.
> My question was about *verifying* that TOC register is restored as it ought
> to, i.e. how the testcase needs to work. Right now, the test uses my code
> from Bugzilla that worked okay for demonstration purposes, but has issues as
> a long-term testsuite addition:
>
> * it demonstrates the issue in a very intransparent fashion, relying on
>    non-obvious interaction with alloca-memset part of the test;
> 
> * when GCC manages to optimize out the alloca-memset part, the test
>    will cease to work for the intended purpose.
> 
> Alexander
> 

Ok. I understand your concern. Let me see if I can change this test to 
check if the TOC was been restored.

Rogerio