From:             [EMAIL PROTECTED]
Operating system: linux-2.2.18
PHP version:      4.0.4pl1
PHP Bug Type:     Reproduceable crash
Bug description:  crash when accessing shared memory + more info on bug #8985


  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);

  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.

                Michal Vitecek

Edit Bug report at:

PHP Development Mailing List <>
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
To contact the list administrators, e-mail: [EMAIL PROTECTED]

Reply via email to