Comment 26 for bug 1885403

I realized that gdb and maps (that I both had already) give me all that I need.
When stopping at a function from libpostfix-tls.so I can print where I am and check which file is mapped there:

Breakpoint 1, tls_log_mask (log_param=0x55555555c6f8 "-L option", log_level=0x5555555728c0 "routine,certmatch") at /build/postfix-9Thbkc/postfix-3.5.6/src/tls/tls_misc.c:545
(gdb) info regs
...
rip 0x7ffff7fa43f8 0x7ffff7fa43f8 <tls_log_mask+20>
$ cat /proc/$(pidof posttls-finger)/maps | grep -e 'xp.*tls.so' -e 'xp.*posttls-finger'
555555557000-55555555c000 r-xp 00003000 00:ba 87205 /usr/sbin/posttls-finger
7ffff7fa0000-7ffff7fb8000 r-xp 00009000 00:ba 86770 /usr/lib/postfix/libpostfix-tls.so

So whatever detail I miss from my ltrace incantaton, the code of tls_log_mask really is from the shared library. And while that makes tracing the calls slightly harder it is relieving as it eliminates at least one kind of craziness :-)