Re: TLS support on NetBSD

[Ludovic Courtès]

Hey,

Ken Raeburn <address@hidden> writes:

> I just took a little bit of a look... on my NetBSD 5.0.1 x86 system,
> the __thread support simply uses the %gs segment register,

That’s weird because it should only do such things with the
‘initial-exec’ or ‘local-exec’ thread models; otherwise, it relies on
support from the C library at run-time, something called
‘__tls_get addr ()’ in glibc.

> but the kernel or library or whatever doesn't seem to have set it up
> properly.  So it compiles and links just fine for me, but crashes when
> running.

Hmm, not good.

> I think the autoconf test is thus going to have to run a test program
> to see if __thread is supported, which means it won't be friendly to
> cross-compilation setups.  (I still don't have all the dependencies
> built for NetBSD, so no working patch.)  Or, we could hard-code
> knowledge about systems where compiling and linking work but execution
> fails; that's generally frowned upon....

Yeah, that doesn’t sound very good.

Thanks,
Ludo’.