From: [EMAIL PROTECTED] Operating system: RedHat Linux 7.1 & 8.0 PHP version: 4.2.2 PHP Bug Type: Apache related Bug description: PHP causes Apache to leak semaphores
This bug has been discussed over at RedHat's Bugzilla. See http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=70846 A quick synopsis of how I get it to misbehave: Create the following simple PHP script and access it through a web browser: <?php $crash = array( 0 => 2, 'test' => 2, 1 => 'hello', 'say' => 'hello', 2 => 42, 'life' => 42, 3 => 'this should help \'crash\' the machine', 'hoho' => 'this should help \'crash\' the machine'); print_r($crash); for( $i=0; $i<count($crash); $i++ ) $crash[$i] = stripslashes($crash[$i]); print_r($crash); ?> It should die with an error similar to this: Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 35 bytes) in /home/****/crash.php on line 14 Reload this page a good 5-10 times. If you run 'ipcs -s' and then restart apache and run 'ipcs -s' again you will find that the number of semaphore arrays has increased and the first few semid's are unchanged (not having been freed when apache shutdown?). If you rinse and repeat the above with a crude shell script like: while [ true ]; do wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php wget -O - http://localhost/crash.php ipcs -s|grep apache|wc /etc/rc.d/init.d/httpd restart sleep 1 ipcs -s|grep apache|wc done then you'll find the semaphore array numbers increasing slowly and apache taking longer and longer to do each restart until eventually (once all 128 semaphore arrays are used) it refuses to start at all with the message reported earlier in this bug (70846): Starting httpd: Ouch! ap_mm_create(1048576, "/var/run/httpd.mm.5619") failed Error: MM: mm:core: failed to acquire semaphore (No space left on device): OS: Invalid argument [FAILED] Just restarting apache in a loop without loading crash.php on a freshly booted system does not cause the number of semaphores to spiral - it stays constant at 5. This is verifyable on multiple RH7.1 and a RH8.0 machine, all fully updated through RHN (except for kernels). RedHat have literally just released an updated mm package which stops the use of kernel semaphores so that the leaks should not cause Apache problems so quickly (ie more than 128 are now allowed), but none-the-less there RedHat agree there is still a PHP problem. Louis -- Edit bug report at http://bugs.php.net/?id=20986&edit=1 -- Try a CVS snapshot: http://bugs.php.net/fix.php?id=20986&r=trysnapshot Fixed in CVS: http://bugs.php.net/fix.php?id=20986&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=20986&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=20986&r=needtrace Try newer version: http://bugs.php.net/fix.php?id=20986&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=20986&r=support Expected behavior: http://bugs.php.net/fix.php?id=20986&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=20986&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=20986&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=20986&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=20986&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=20986&r=dst IIS Stability: http://bugs.php.net/fix.php?id=20986&r=isapi
