glibc ifunc

[Florian Weimer]

* 赵爱南:

>>>What kind of documentation are you looking for?
>
>
>  I can learn how to modify glibc code to achieve ifunc functionality
>  in this document. As you said, the elf_machine_rela function can be
>  implemented, but is this function only a part of it, rather than the
>  complete one? Thanks.

Changing elf_machine_rela and implementing elf_ifunc_invoke is
sufficient if the architecture provides means for code to discover
which CPU features are implemented at run time.  If this is not the
case, you need to design some mechanism (perhaps HWCAP, perhaps
something else) and pass the required information to the IFUNC
resolver.