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

On Sun, 29 Nov 2015, Konstantin Belousov wrote:

> On Sun, Nov 29, 2015 at 01:23:04AM -0500, Daniel Eischen wrote:
>> 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.
>
> I did the following on the librt from the HEAD of about month ago:
>
> pooma% ls -l netboot/sandy/usr/lib/librt.so.1
> -r--r--r--  1 root  wheel  23704 Oct 24 23:35 netboot/sandy/usr/lib/librt.so.1
>
> pooma% readelf -sw netboot/sandy/usr/lib/librt.so.1 | grep GLOBAL | grep -v UND | grep -v FBSDpriv | grep FBSD
>    97: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS FBSD_1.0
>
> But I think that your commit is the good change.


Can you check librt.so.1 in your buildworld temporary build
environment?

   $ readelf -sW /usr/obj/usr/FreeBSD/svn/src/tmp/usr/lib/librt.so.1 \
      grep -v UND | grep GLOBAL

There has to be a reason that tests/sys/mqueue/mqtest[3-4].c build
without error when they reference __mq_oshandle.  That symbol is
not exported from librt.

Hmm, looks like libc and libthr are also the same (leaky) in the
temporary build environment (TBE).  So something broke when building
the TBE libraries.

For r277320 on my system Jan 19, 2015, the TBE libraries must have
been built correctly because mqtests[3-4] failed with unresolved
references to __mq_oshandle.

-- 
DE