Re: [PATCH v2] ELF: supply userspace with available page shifts (AT_PAGE_SHIFT_MASK)

Florian Weimer
2023-12-08T18:35:31Z

* Kees Cook:

> I significantly prefer APIs not being arch-specific, so I'd prefer we
> always include AT_PAGE_SHIFT_MASK. For an architecture that doesn't
> define its own ARCH_AT_PAGE_SHIFT_MASK, it's not _inaccurate_ to report
> 1 << PAGE_SHIFT, but it might be incomplete.

The downside is that as an application programmer, I have to go and
chase for the information the legacy way if I encounter
getauxval(AT_PAGE_SHIFT_MASK) == getpagesize() for a longer time
because the interface does not signal the absence of any extended
page sizes.

Thanks,
Florian