Public bug reported: I was looking to debug postfix on Bionic today due to a FIPS OpenSSL issue, but failed. ~sergiodj on #ubuntu-devel came to the realization that the debug symbols shipped in postfix-dbgsym (and likely the other postfix-*-dbgsym packages) lacked DWARF information.
This means gdb & friends won't load debug symbols when debugging postfix. When following http://www.postfix.org/DEBUG_README.html: GNU gdb (Ubuntu 8.1.1-0ubuntu1) 8.1.1 Copyright (C) 2018 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/lib/postfix/sbin/smtpd...Reading symbols from /usr/lib/debug/.build-id/9b/c4e924c12d39a5f8577f7bf3432ccafc11bed9.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. Attaching to program: /usr/lib/postfix/sbin/smtpd, process 14989 Reading symbols from /usr/lib/postfix/libpostfix-master.so...Reading symbols from /usr/lib/debug/.build-id/a0/30c76af3133e70f6c5e83b1e8706fe4488d327.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. Reading symbols from /usr/lib/postfix/libpostfix-tls.so...Reading symbols from /usr/lib/debug/.build-id/3f/aa67e6a05ec7c431510aa282e437d189a93558.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. Reading symbols from /usr/lib/postfix/libpostfix-dns.so...Reading symbols from /usr/lib/debug/.build-id/c7/fbba4a5d9f5799be077de3bcb5c4a0af98ea41.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. Reading symbols from /usr/lib/postfix/libpostfix-global.so...Reading symbols from /usr/lib/debug/.build-id/7c/01ebd867e112fcc7c36cffda34d5b41625456d.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. Reading symbols from /usr/lib/postfix/libpostfix-util.so...Reading symbols from /usr/lib/debug/.build-id/3a/6656b78d2fbd615d9204b39ea4b75cad264f97.debug...(no debugging symbols found)...done. (no debugging symbols found)...done. ... snip ... Breakpoint 1, rand_drbg_restart (drbg=0x5603edebd000, buffer=0x7f5664352cb0 <randseed> "\215:", len=24, entropy=192) at ../crypto/rand/drbg_lib.c:478 478 { (gdb) backtrace #0 rand_drbg_restart (drbg=0x5603edebd000, buffer=0x7f5664352cb0 <randseed> "\215:", len=24, entropy=192) at ../crypto/rand/drbg_lib.c:478 #1 0x00007f5662cbff55 in drbg_add (buf=0x7f5664352cb0 <randseed>, num=24, randomness=<optimized out>) at ../crypto/rand/drbg_lib.c:982 #2 0x00007f566414ab77 in tls_server_start () from /usr/lib/postfix/libpostfix-tls.so #3 0x00005603ecb66eed in smtpd_start_tls () #4 0x00005603ecb676b8 in starttls_cmd () #6 0x0000558df1c52a32 in smtpd_service () #7 0x00007fd3ae0c47aa in single_server_wakeup () from /usr/lib/postfix/libpostfix-master.so #8 0x00007fd3ad832d28 in event_loop () from /usr/lib/postfix/libpostfix-util.so #9 0x00007fd3ae0c56a8 in single_server_main () from /usr/lib/postfix/libpostfix-master.so #10 0x0000558df1c4bb50 in main () Notice the warnings from gdb and missing mapping information on the Postfix functions. This remains even though OpenSSL debug information is present and loads properly. Packages: [root@ubuntu-1804-base-fips openssl-1.1.1]# dpkg --list | grep -i postfix ii postfix 3.3.0-1ubuntu0.3 amd64 High-performance mail transport agent ii postfix-cdb 3.3.0-1ubuntu0.3 amd64 CDB map support for Postfix ii postfix-cdb-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-cdb ii postfix-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix ii postfix-ldap 3.3.0-1ubuntu0.3 amd64 LDAP map support for Postfix ii postfix-ldap-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-ldap ii postfix-lmdb 3.3.0-1ubuntu0.3 amd64 LMDB map support for Postfix ii postfix-lmdb-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-lmdb ii postfix-mysql 3.3.0-1ubuntu0.3 amd64 MySQL map support for Postfix ii postfix-mysql-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-mysql ii postfix-pcre 3.3.0-1ubuntu0.3 amd64 PCRE map support for Postfix ii postfix-pcre-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-pcre ii postfix-pgsql 3.3.0-1ubuntu0.3 amd64 PostgreSQL map support for Postfix ii postfix-pgsql-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-pgsql ii postfix-sqlite 3.3.0-1ubuntu0.3 amd64 SQLite map support for Postfix ii postfix-sqlite-dbgsym 3.3.0-1ubuntu0.3 amd64 debug symbols for postfix-sqlite This is confirmed by eu-readelf -w on one of the debug files: $ eu-readelf -w /usr/lib/debug/.build- id/3f/aa67e6a05ec7c431510aa282e437d189a93558.debug Thus this is a bug in postfix packaging. I have not tested this on later versions of the postfix from later Ubuntu releases. ** Affects: postfix (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1931306 Title: bionic: postfix-dbgsym package lacks DWARF information To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/1931306/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs