librt symbol versioning breakage (was Re: Build failure, undefined reference to __mq_oshandle)

On Fri, 27 Nov 2015, Daniel Eischen wrote:

> Damn, please use deischen_at_freebsd.org for replies.
>
> On Fri, 27 Nov 2015, Daniel Eischen wrote:
>
>> On Fri, 27 Nov 2015, Daniel Eischen wrote:
>> 
>>> $ uname -a
>>> FreeBSD vega 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r277320: Mon Jan 19 
>>> 09:02:50 EST 2015 
>>> deischen_at_vega:/usr/FreeBSD/svn/obj/usr/FreeBSD/svn/src/sys/vega  amd64
>>> 
>>> Upgrading to today's current, 'rm -rf /usr/obj/*; make -j8 buildworld'
>>> fails here:
>>> 
>>> ===> lib/libc/tests/gen/execve (buildconfig)
>>> --- all_subdir_tests ---
>>> --- all_subdir_mqueue ---
>>> mqtest3.o: In function `main':
>>> /usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x139): undefined 
>>> reference to `__mq_oshandle'
>>> /usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x14c): undefined 
>>> reference to `__mq_oshandle'
>>> /usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x16c): undefined 
>>> reference to `__mq_oshandle'
>>> /usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x3e6): undefined 
>>> reference to `__mq_oshandle'
>>> /usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x3f9): undefined 
>>> reference to `__mq_oshandle'
>>> mqtest3.o:/usr/FreeBSD/svn/src/tests/sys/mqueue/mqtest3.c:(.text+0x40f): 
>>> more undefined references to `__mq_oshandle' follow
>>> cc: error: linker command failed with exit code 1 (use -v to see 
>>> invocation)
>>> 
>>> Going to try make [-j1], next, but anyone come across this?
>> 
>> Still fails.
>> 
>> Why do the tests in tests/sys/mqueue/ try to use non-public APIs?

So I found out that sometime in the last year or so, symbol versioning
for librt was broken and leaking symbols that shouldn't have been
leaked.  I've just committed a fix for this.

Do a 'readelf -sw /usr/lib/librt.so.1 | grep GLOBAL | grep -v UND'
and see the non FBSD_foo symbols that shouldn't be there.

-- 
DE