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

* Alexey Dobriyan:

On Wed, Dec 06, 2023 at 12:47:27PM -0800, Kees Cook wrote:

quoted

On Tue, Dec 05, 2023 at 07:01:34PM +0300, Alexey Dobriyan wrote:

quoted

Report available page shifts in arch independent manner, so that
userspace developers won't have to parse /proc/cpuinfo hunting
for arch specific strings:

Note!

This is strictly for userspace, if some page size is shutdown due
to kernel command line option or CPU bug workaround, than is must not
be reported in aux vector!

Given Florian in CC, I assume this is something glibc would like to be
using? Please mention this in the commit log.

glibc can use it. Main user is libhugetlbfs, I guess:

	https://github.com/libhugetlbfs/libhugetlbfs/blob/master/hugeutils.c#L915

Loop inside getauxval() can run faster than opendir().

Is libhugetlbfs still maintained?  Last commit was three years ago?

Thanks,
Florian