Debugging NewsCache - A Short Guide =================================== Author: Herbert Straub e-mail: herbert@linuxhacker.at Date: 2004-06-10 Debugging with newsache -i: --------------------------- The newscache can be started with -i option and read the NNTP Commands from stdin. Here we can start the debugging session and can test the newscache. Example: -------- GNU gdb 6.1-debian Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-linux"...Using host libthread_db library "/lib/libthread_db.so.1". (gdb) set args -i (gdb) run Starting program: /home/stb/products/NewsCache/src/newscache -i 200 NewsCache 1.1.92-1, accepting NNRP commands group at.linux 211 20775 155229 176003 at.linux group selected quit 205 Good bye Program exited normally. (gdb) Debugging with process attachment: ---------------------------------- Attach to the client process (searched from the newscache logfile): gdb GNU gdb 6.1-debian Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-linux". (gdb) attach 26017 Attaching to process 26017 Reading symbols from /usr/sbin/newscache...done. Using host libthread_db library "/lib/libthread_db.so.1". Reading symbols from /usr/lib/libsocket++.so.1...done. Loaded symbols for /usr/lib/libsocket++.so.1 Reading symbols from /lib/libwrap.so.0...done. Loaded symbols for /lib/libwrap.so.0 Reading symbols from /lib/libcrypt.so.1...done. Loaded symbols for /lib/libcrypt.so.1 Reading symbols from /lib/libnsl.so.1...done. Loaded symbols for /lib/libnsl.so.1 Reading symbols from /lib/libdl.so.2...done. Loaded symbols for /lib/libdl.so.2 Reading symbols from /lib/libpam.so.0...done. Loaded symbols for /lib/libpam.so.0 Reading symbols from /usr/lib/libstdc++.so.5...done. Loaded symbols for /usr/lib/libstdc++.so.5 Reading symbols from /lib/libm.so.6...done. Loaded symbols for /lib/libm.so.6 Reading symbols from /lib/libgcc_s.so.1...done. Loaded symbols for /lib/libgcc_s.so.1 Reading symbols from /lib/libc.so.6...done. Loaded symbols for /lib/libc.so.6 Reading symbols from /lib/ld-linux.so.2...done. Loaded symbols for /lib/ld-linux.so.2 Reading symbols from /lib/libnss_files.so.2...done. Loaded symbols for /lib/libnss_files.so.2 Reading symbols from /lib/libnss_compat.so.2...done. Loaded symbols for /lib/libnss_compat.so.2 Reading symbols from /lib/libnss_nis.so.2...done. Loaded symbols for /lib/libnss_nis.so.2 0x40251b08 in read () from /lib/libc.so.6 (gdb) cont Continuing. Program received signal SIGSEGV, Segmentation fault. 0x40124b89 in std::string::length () from /usr/lib/libstdc++.so.5 (gdb) bt #0 0x40124b89 in std::string::length () from /usr/lib/libstdc++.so.5 #1 0x08056b79 in check_auth_pam (clt=0xbffff440) at NewsCache.cc:708 #2 0x08056db3 in check_authentication (clt=0xbffff440) at NewsCache.cc:748 #3 0x080577c7 in ns_authinfo (clt=0xbffff440, argc=3, argv=0xbfffe830) at NewsCache.cc:928 #4 0x0805b86d in nnrpd (fd=1) at NewsCache.cc:2137 #5 0x0805c2b5 in nntpd () at NewsCache.cc:2331 #6 0x0805d862 in main (argc=1, argv=0xbffffe34) at NewsCache.cc:2701 (gdb)
