About gprofng/30006 - Failure to build binutils-2.40 gprofng using gold

[Vladimir Mezentsev]

  Hello Linux Experts,

The original problem is here:
30006 - Failure to build binutils-2.40 gprofng using gold
https://sourceware.org/bugzilla/show_bug.cgi?id=30006


I prepared a small test that demonstrates the problem:

% cat test.c
void *dlopen (const char *pathname, int mode)
   { return (void *) 0; }

__attribute__ ((__symver__ ("dlopen@GLIBC_2.1")))
void *__collector_dlopen_2_1 (const char *pathname, int mode)
   { return (void *) 0; }

__attribute__ ((__symver__ ("dlopen@GLIBC_2.0")))
void *__collector_dlopen_2_0 (const char *pathname, int mode)
   { return (void *) 0; }

int main()
   { return 0; }


% cat map.txt
GLIBC_2.0 {
     global:
        dlopen;
};

GLIBC_2.1 {
     global:
         dlopen;
};


There are no problems with -fuse-ld=bfd:
% /opt/rh/gcc-toolset-10/root/bin/gcc -m32 test.c -Wl,--version-script 
-Wl,map.txt  -fuse-ld=bfd

The output of `nm` shows exactly what I expected:
% nm a.out | grep dlopen
08049191 T __collector_dlopen_2_0
08049187 T __collector_dlopen_2_1
0804917d t dlopen
08049191 t dlopen@GLIBC_2.0
08049187 t dlopen@GLIBC_2.1


But with -fuse-ld=gold:
% /opt/rh/gcc-toolset-10/root/bin/gcc -m32 test.c -Wl,--version-script 
-Wl,map.txt  -fuse-ld=gold
/bin/ld.gold: warning: /tmp/cc6YCOol.o: unknown program property type 
0xc0010001 in .note.gnu.property section
/bin/ld.gold: warning: using 'GLIBC_2.0' as version for 'dlopen' which 
is also named in version 'GLIBC_2.1' in script
/bin/ld.gold: error: /tmp/cc6YCOol.o: multiple definition of 'dlopen'
/bin/ld.gold: /tmp/cc6YCOol.o: previous definition here
collect2: error: ld returned 1 exit status


My questions:

Is my test correct ?
if not:
   we need to interpose the dlopen functions from libdl.so.
   How can I do it correctly ?

If yes:
Is this a known compiler bug in gold ? If not, do I need to create one ?
   Is there a simple workaround ?

Thank you,
-Vladimir