Re: [PATCH glibc] nptl_db: different libpthread/ld.so load orders (bug 27744)

[Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>]

* Pedro Alves:

> IIRC, the order which libraries are loaded by GDB hasn't changed.  The
> issue is that until recently (before glibc 1daccf403b1b), the stacks
> lists lived in libpthread (stack_used/__stack_user), so the fact that
> GDB loaded libthread_db.so before ld.so's symbols were loaded didn't
> make a difference.  Now they were moved to ld.so, so libthread_db.so
> can't find them until GDB reads the ld.so symbols.  Is this assessment
> correct?

Yes, I believe this is what happens.

I assume that ldd shows objects in link map order, the it looks like
this:

$ ldd /usr/bin/python3
	linux-vdso.so.1 (0x00007fff1f8d5000)
	libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f3fd7782000)
	libc.so.6 => /lib64/libc.so.6 (0x00007f3fd75b7000)
	libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3fd7595000)
	libdl.so.2 => /lib64/libdl.so.2 (0x00007f3fd758e000)
	libutil.so.1 => /lib64/libutil.so.1 (0x00007f3fd7589000)
	libm.so.6 => /lib64/libm.so.6 (0x00007f3fd7443000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f3fd7af7000)

Thanks,
Florian