Bug #9259 Updated: crash when accessing shared memory + more info on bug #8985

ID: 9259 Updated by: lobbin Reported By: fuf@mobil.cz Status: Open Bug Type: Semaphore related Operating System: linux-2.2.18 PHP Version: 4.0.4pl1 New Comment: Does this happen on 4.1.1? Previous Comments: ------------------------------------------------------------------------ [2001-02-14 08:47:01] fuf@mobil.cz hello, when accessing a shared memory region that i don't have access to (because of the permissions), php segfaults. so if i have a shared memory region created by another user with key 0x123 and permissions 0600 and call shm_attach(0x123), php crashes: <? $shmid = shm_attach(0x123); shm_detach(0x123); ?> also, i know some more info concerning the bug #8985: when one process is reading some variable from the shared memory and some other is writing _another_ variable to the same shared memory region, the data gets corrupted - possibly because of the reorganizing before each shm_put_var(). while this is understandable (shm_put_var() first removes the variable, reorganizes the region and writes the variable back), it renders this extension almost unusable in multitasking environments because a big global lock for the whole shared memory region is needed. i can supply more information if needed of course. thanks, Michal Vitecek ------------------------------------------------------------------------ Edit this bug report at http://bugs.php.net/?id=9259&edit=1