Provide string functions for use before ifuncs get resolved.

[mjg]

Summary

The change is a no-op for architectures which don't ifunc memset, memcpy nor memmove.

Test Plan

tinderbox, royger's use case

[royger]

Thanks, this allows to fix the Xen boot issue. Would you mind including the following diff into your patch?

http://xenbits.xen.org/people/royger/fix_early_memset.patch

I think it's much better if the patch also fixes the current usages, or else you are introducing a set of functions that are unused.

[kib]

In D17487#373303, @royger wrote:

Thanks, this allows to fix the Xen boot issue. Would you mind including the following diff into your patch?

http://xenbits.xen.org/people/royger/fix_early_memset.patch

I think it's much better if the patch also fixes the current usages, or else you are introducing a set of functions that are unused.

There is also the use in link_elf.c:link_elf_ireloc().

sys/amd64/include/cpufunc.h

1019 ↗

(On Diff #48950)

cpufunc.h is definitely wrong place. I suggested cpu.h.

[mjg]

• move macros to cpu.h
• convert current hand-rolled code to use early, xen bits from royger

[imp]

Is there any way to know you've got them all?