serialize segfault

Hi all,

I'm trying to track down a segfault to do with serializing an object.

I can't reproduce it with a small script so I'm not sure where to go from
here. Any suggestions, tips, helpful hints greatly appreciated.

It's part of a largish CMS which uses lots of circular references so
pasting an example isn't easy.

Here's a backtrace:

(gdb) bt
#0 0x4023d67e in php_var_serialize_class_name (buf=0xbffddf20,
struc=0x8bd961c)
at /usr/src/php-4.3.2/ext/standard/var.c:416
#1 0x4023c899 in php_var_serialize_class (buf=0xbffddf20, struc=0x8bd961c,
retval_ptr=0x8b43dec, var_hash=0xbffddf30)
at /usr/src/php-4.3.2/ext/standard/var.c:430
#2 0x4023cdf5 in php_var_serialize_intern (buf=0xbffddf20,
struc=0x8bd961c, var_hash=0xbffddf30)
at /usr/src/php-4.3.2/ext/standard/var.c:549
#3 0x4023d05b in php_var_serialize (buf=0xbffddf20, struc=0x8bd961c,
var_hash=0xbffddf30)
at /usr/src/php-4.3.2/ext/standard/var.c:623
#4 0x4023d108 in zif_serialize (ht=1, return_value=0x88340d4,
this_ptr=0x0, return_value_used=1)
at /usr/src/php-4.3.2/ext/standard/var.c:646
#5 0x402c8947 in execute (op_array=0x8cb5da4) at
/usr/src/php-4.3.2/Zend/zend_execute.c:1606

(gdb) frame 5
#5 0x402c8947 in execute (op_array=0x8cb5da4) at
/usr/src/php-4.3.2/Zend/zend_execute.c:1606
1606
((zend_internal_function *)
EX(function_state).function)->handler(EX(opline)->extended_value,
EX(Ts)[EX(opline)->result.u.var].var.ptr, EX(object).ptr, return_value_used
TSRMLS_CC);

(gdb) print (char
*)(executor_globals.function_state_ptr->function)->common.function_name
$1 = 0x4030831b "serialize"

$ gcc -v
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs
gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-113)

Can anyone give me a hand with tracking down the problem?

Thanks!
Chris.