[OpenSIPS-Devel] trying to examine presence/timer crash

[Juha Heinanen]

Juha Heinanen writes:

> (gdb) where
> #0  0xb758e3e3 in db_mysql_val2bind (v=0xbfcbdf3c, binds=0x8188190, i=1)
>     at val.c:274
> #1  0xb758993e in db_mysql_do_prepared_query (conn=<value optimized out>, 
>     v=<value optimized out>, n=2, uv=0x0, un=0, query=<value optimized out>)
>     at dbase.c:443
> #2  0xb758b0dd in db_mysql_delete (_h=0x817c1a0, _k=0xbfcbdf70, 
>     _o=0xbfcbdf64, _v=0xbfcbdf28, _n=2) at dbase.c:893
> #3  0xb723dea4 in msg_watchers_clean (ticks=3600, param=0x0)
>     at subscribe.c:484
> #4  0x080b64cf in timer_ticker () at timer.c:325
> #5  run_timer_process () at timer.c:395
> #6  start_timer_processes () at timer.c:475
> #7  0x08069ea3 in main_loop (argc=16, argv=0xbfcbe134) at main.c:867
> #8  main (argc=16, argv=0xbfcbe134) at main.c:1388

a bit more about this.  at frame 2, i can get value of v.  the function
and call of db_mysql_do_prepared_query:

int db_mysql_delete(const db_con_t* _h, const db_key_t* _k, const db_op_t* _o,
	const db_val_t* _v, const int _n)
...
	ret = db_mysql_do_prepared_query(_h, &query_holder, _v, _n, NULL, 0);

(gdb) frame 2
#2  0xb758b0dd in db_mysql_delete (_h=0x817c1a0, _k=0xbfcbdf70, 
    _o=0xbfcbdf64, _v=0xbfcbdf28, _n=2) at dbase.c:893
893			ret = db_mysql_do_prepared_query(_h, &query_holder, _v, _n, NULL, 0);
(gdb) info args
_h = 0x817c1a0
_k = 0xbfcbdf70
_o = 0xbfcbdf64
_v = 0xbfcbdf28
_n = 2
(gdb) print _v->type
$7 = DB_INT

but when in frame 1 (in db_mysql_do_prepared_query):

static int db_mysql_do_prepared_query(const db_con_t* conn, const str *query,
	const db_val_t* v, int n, const db_val_t* uv, int un)
...
	if (db_mysql_val2bind( v+i , mysql_bind, i)<0 ) {

(gdb) info args
conn = <value optimized out>
v = <value optimized out>
n = 2
uv = 0x0
un = 0
query = <value optimized out>
gdb) print v->type
Cannot access memory at address 0x0

perhaps v has changed in db_mysql_do_prepared_query before
db_mysql_val2bind call?

-- juha