Hi, currently all memory allocated with emalloc has a zend_mem_header infront of it. This header contains the backward and forward pointer and the size of this block. My question is: is there any need for this linked list on a production system? I commented the ADD_POINTER_TO_LIST and REMOVE_POINTER_FROM_LIST macros out and havent seen any impact (but infact I only run phpinfo() and some basic scripts). From the rest of the code the linked list doesn't look used at all. If this linked list is only for finding memory leaks etc., we should remove it from the release. (I did wrap the macro definition with #if ZEND_DEBUG)
The reasons for removing are: wasted cpu time and the danger that comes with those macros. As an example the bufferoverflow in PHP3 was only exploitable on most systems because of these 2 macros. With them removed the overflow would have been exploitable only on Solaris/Linux and maybe Windows. Stefan Esser -- PHP Development Mailing List <http://www.php.net/> To unsubscribe, visit: http://www.php.net/unsub.php
