[SR-Users] segmentation fault in init_mod_child function

[Timo Reimann]

Hey Bruno,


Am 09.11.2011 um 20:31 schrieb Bruno Bresciani:
> Kamailio 3.1.2 terminated with signal 11, segmentation fault, in the init_mod_child function at sr_module.c file. This problem occurs only when I try loading the loadbalance.so module, it was written by me. 
> 
> Someone Can help me to understand why this segmentation fault was generated? There are two other module written by me and this problem doesn't happen.
> 
> Kamailio's trace:
> 
> 9(27616) DEBUG: db_postgres [km_pg_con.c:80]: PQsetdbLogin(0x8db2878)
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): sl
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): auth_db
>  9(27616) DEBUG: <core> [db.c:294]: connection 0x82f4108 found in pool
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): usrloc
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): mi_fifo
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): registrar
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): nathelper
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): permissions
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): loadbalance
>  9(27616) DEBUG: loadbalance [loadbalance_mod.c:271]: loadbalance: child started! (5)
>  9(27616) DEBUG: <core> [sr_module.c:828]: DEBUG: init_mod_child (5): route
>  0(27582) ALERT: <core> [main.c:741]: child process 27585 exited by a signal 11
>  0(27582) ALERT: <core> [main.c:744]: core was generated
>  0(27582) INFO: <core> [main.c:756]: INFO: terminating due to SIGCHLD
>  8(27615) INFO: <core> [main.c:807]: INFO: signal 15 received
>  8(27615) DEBUG: <core> [main.c:818]: Memory status (pkg):
>  8(27615) DEBUG: fm_status: fm_status (0x82aefc0):
>  8(27615) DEBUG: fm_status:  heap size= 4194304
>  8(27615) DEBUG: fm_status:  used= 236720, used+overhead=264064, free=3930240
>  8(27615) DEBUG: fm_status:  max used (+overhead)= 299824
>  8(27615) DEBUG: fm_status: dumping free list:
>  8(27615) DEBUG: fm_status: hash =   1 fragments no.:    27, unused:     0
>                  bucket size:         8 -         8 (first         8)
>  8(27615) DEBUG: fm_status: hash =  44 fragments no.:     1, unused:     0
>                  bucket size:       352 -       352 (first       352)
>  8(27615) DEBUG: fm_status: hash =  74 fragments no.:     1, unused:     0
>                  bucket size:       592 -       592 (first       592)
>  8(27615) DEBUG: fm_status: hash =  77 fragments no.:     1, unused:     0
>                  bucket size:       616 -       616 (first       616)
>  8(27615) DEBUG: fm_status: hash =  81 fragments no.:     1, unused:     0
>                  bucket size:       648 -       648 (first       648)
>  8(27615) DEBUG: fm_status: hash =  84 fragments no.:     1, unused:     0
>                  bucket size:       672 -       672 (first       672)
>  8(27615) DEBUG: fm_status: hash = 113 fragments no.:    51, unused:     0
>                  bucket size:       904 -       904 (first       904)
>  8(27615) DEBUG: fm_status: hash = 2056 fragments no.:     1, unused:     0
> 
> 
> gdb bt full trace:
> 
> 
> Reading symbols from /media/sda1/local/kamailio/lib/kamailio/modules/route.so...done.
> Loaded symbols for /home2/local/kamailio/lib/kamailio/modules/route.so
> Reading symbols from /media/sda1/local/kamailio/lib/kamailio/modules/rtpproxy.so...done.
> Loaded symbols for /home2/local/kamailio/lib/kamailio/modules/rtpproxy.so
> Reading symbols from /media/sda1/local/kamailio/lib/kamailio/modules/tls.so...done.
> Loaded symbols for /home2/local/kamailio/lib/kamailio/modules/tls.so
> Reading symbols from /media/sda1/local/kamailio/lib/kamailio/modules/perms_db.so...done.
> Loaded symbols for /home2/local/kamailio/lib/kamailio/modules/perms_db.so
> Reading symbols from /lib/libnss_files.so.2...done.
> Loaded symbols for /lib/libnss_files.so.2
> Reading symbols from /lib/libnss_dns.so.2...done.
> Loaded symbols for /lib/libnss_dns.so.2
> Core was generated by `/home2/local/kamailio/sbin/kamailio -P /var/run/kamailio.pid'.
> Program terminated with signal 11, Segmentation fault.
> #0  init_mod_child (m=0xa238, rank=2) at sr_module.c:827
> 827     sr_module.c: Arquivo ou diretório não encontrado.
>         in sr_module.c
> (gdb)
> (gdb)
> (gdb)
> (gdb)
> (gdb)
> (gdb)
> (gdb) bt full
> #0  init_mod_child (m=0xa238, rank=2) at sr_module.c:827
> No locals.
> #1  0x00000000 in ?? ()
> No symbol table info available.
> (gdb)

The address of the "m" struct in init_mod_child looks awkward. Although it's non-null, it's probably not within the validity range of the process's address space, thereby causing a segfault. You can verify this by investigating the coredump in gdb and printing m's content with "print m". If my assumption holds, try figuring out why m became messy in the first place.


HTH,

--Timo