Re: PR lib/59751: dlclose is not MT-safe depending on the libraries unloaded

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Mon, 20 Jul 2026 21:38:42 +0200
> From: Anthony Mallet <anthony.mallet%laas.fr@localhost>
> 
> To test, I only disabled DEBUG in the Makefile (the build was failing
> with undefined symbols like xassert etc., as I only built ld.elf_so).

Sorry -- requires `make cleandir' in src/libexec/ld.elf_so, since the
makefile dependencies don't capture changes to CPPFLAGS.

> Also, I removed the lo, hi variables in tls.c as, without debug, -Werror
> was complaining about set but unsued vars.

Oops -- should be fixed now in tls.c 1.31.

> Are you confident with your changes ? (I mean should I revert
> ld.elf_so to ~16/07/2026 to avoid any regression or do you prefer me
> continuing to test this a bit?)

Please test!  I have fixed all the ld.elf_so issues I am aware of now
except for one low-probability crash in multithreaded recursive
dlopen/dlclose under pathological abuse of the functions.