linux uml segfault

[Johannes Berg]

On Thu, 2021-03-04 at 14:38 +0900, Hajime Tazaki wrote:

> > Now, I don't know how to fix it (short of changing your nsswitch
> > configuration) - maybe we could somehow rename sem_init()? Or maybe we
> > can somehow give the kernel binary a lower symbol resolution than the
> > libc/libpthread.
> 
> objcopy (from binutils) can localize symbols (i.e., objcopy -L
> sem_init $orig_file $new_file).  It also does renaming symbols.  But
> not sure this is the ideal solution.

Yes, we started thinking about it but it was too late at night when I
replied ...

I think there's basically a way to have an external list of symbols to
export, for symbol versioning, that we could/should use to basically not
export any of the kernel symbols out to libs.

> How does UML handle symbol conflicts between userspace code and Linux
> kernel (like this case sem_init) ?  AFAIK, libnl has a same symbol as
> Linux kernel (genlmsg_put) and others can possibly do as well.

I fear it doesn't?

johannes