Hacker News new | ask | show | jobs
by mikepavone 439 days ago
> It's the exception which is why it's talked about the most.

It's definitely not the only exception. libgl is another obvious example since different GPUs need different userland code. I would be surprised if there there had never been compat regressions in those.
1 comments
HexDecOctBin 439 days ago
libgl can be dlopened, glibc can't be. That is the problem. If libgl has some incompatibility, I can try to work around that. If glibc has some incompatibility, my executable won't even launch.

I agree with this article completely.

link
dataflow 439 days ago
> libgl can be dlopened, glibc can't be. That is the problem.

What exactly prevents this for glibc? I assume you'd need a dlopen equivalent from somewhere for bootstrapping, but are there other issues (like TLS or whatnot)?

link
HexDecOctBin 439 days ago
Yeah, TLS is one reason. I don't remember the details, but last time I looked into it, glibc abd the loader have some private interface that they use to load the program correctly, and there are no stability guarantees for this interface. Ideally, the loader and libdl will ship with the kernel, and glibc will have to use the public interface they expose.
link
dataflow 438 days ago
If that's the case then it feels like it proves they just don't care enough about compatibility...
link