Re: [PATCH v6 3/6] fs/procfs: add build ID fetching to PROCMAP_QUERY API

[Andi Kleen]

> Yep, makes sense. I'm currently reworking this whole lib/buildid.c
> implementation to remove all the restrictions on data being in the
> first page only, and making it work in a faultable context more
> reliably. I can audit the code for TOCTOU issues and incorporate your
> feedback. I'll probably post the patch set next week, will cc you as
> well.

Please also add checks that the mapping is executable, to
close the obscure "can check the first 4 bytes of every mapped 
file is ELF\0" hole.

But it will still need the hardening because mappings from
ld.so are not EBUSY for writes.

-Andi