On Sun, Apr 12, 2020 at 11:27 AM Nicolas Iooss <nicolas.iooss@xxxxxxx> wrote: > > Hello, > Since recent changes in libsemanage.so's linker script, I have been > experiencing issues. As I encountered these issues only when I was > using a build configuration which is slightly different from what is > in the repository, I wanted to spend time to investigate what was > going on before eventually submitting a proper bug report. > The issue I see is the following: when I compile with the gold linker > and a custom set of build options, linking libsemanage.so fails with > [1]: > > /usr/bin/ld.gold: warning: using 'LIBSEMANAGE_1.0' as version for > 'semanage_get_hll_compiler_path' which is also named in version > 'LIBSEMANAGE_1.1' in script > /usr/bin/ld.gold: warning: using 'LIBSEMANAGE_1.0' as version for > 'semanage_get_ignore_module_cache' which is also named in version > 'LIBSEMANAGE_1.1' in script > /usr/bin/ld.gold: warning: using 'LIBSEMANAGE_1.0' as version for > 'semanage_set_ignore_module_cache' which is also named in version > 'LIBSEMANAGE_1.1' in script > ... Does it actually fail or just print these warnings? IIRC, @sds replied with some superfluous linking warnings, but we ignored them. I tried looking through my mail and the archive but I couldn't find it. > > Looking back at a normal build of current git master (that succeeded), > I indeed have: > > $ objdump -T libsemanage/src/libsemanage.so | grep > semanage_get_hll_compiler_path > 000000000001b9b0 g DF .text 000000000000021c LIBSEMANAGE_1.0 > semanage_get_hll_compiler_path > > The same command on libsemanage 3.0 (last release) gives: > > $ objdump -T /usr/lib/libsemanage.so | grep semanage_get_hll_compiler_path > 000000000001a3c0 g DF .text 0000000000000224 LIBSEMANAGE_1.1 > semanage_get_hll_compiler_path > > In short, semanage_get_hll_compiler_path is defined twice in > libsemanage/src/libsemanage.map [2] and the linker only provides the > first one. In fact, libsemanage.so built from git master has currently > only 2 functions in LIBSEMANAGE_1.1: > > $ objdump -T libsemanage/src/libsemanage.so | grep LIBSEMANAGE_1.1 > 000000000001e1f0 g DF .text 000000000000010d LIBSEMANAGE_1.1 > semanage_module_install > 000000000001eea0 g DF .text 000000000000011f LIBSEMANAGE_1.1 > semanage_module_get_enabled > > These functions changed their API between versions 1.0 and 1.1, so > this is normal (there are .symver macros in the code and they work > properly). The issue is that all the other symbols went into > LIBSEMANAGE_1.0 instead of LIBSEMANAGE_1.1. Is this a bug or did I > misunderstand something? Should the duplicated functions be removed > from LIBSEMANAGE_1.0 in libsemanage.map? objdump -T is probably a better way to do this than what I had with readelf, as it shows the version. Let me roll a patch, I probably have to go through the others as well. > > Thanks, > Nicolas > > [1] https://travis-ci.org/github/fishilico/selinux/jobs/674002033#L2471 > [2] https://github.com/SELinuxProject/selinux/blob/aa40067b7b86d5e4c951fccae1aa98baff148613/libsemanage/src/libsemanage.map >
