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Re: Fix hppa/ia64/microblaze executable stack default (bug 22156)


On Tue, 19 Sep 2017, Jeff Law wrote:

> > I thought that PF_X was required for hppa because there was still code
> > generated by gcc for hppa that needed it? Otherwise *I* would have
> > removed it when I did the PT_GNU_STACK cleanups for all the arches.
> > 
> > Dave is the best positioned to answer this question.
> I don't think the PA was ever converted to the new bits from the Adacore
> guys -- meaning I think it still generates executable stack trampolines
> for nested functions.
> 
> Dave would know for sure :-)

If Andreas's description of the kernel default is correct, I'd expect that 
to mean that any attempt to call a pointer to a nested function would 
already fail because the kernel had in fact mapped the stack 
non-executable (so the glibc patch would accurately reflect what the 
kernel does - a GCC patch would *also* be needed for pointers to nested 
functions to work, but it would only need to output stack markers in the 
case where trampolines had been generated, to request an executable stack 
in that case).

-- 
Joseph S. Myers
joseph@codesourcery.com


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