Bug #74403 [NEW]: Sporadi

From: tony2001 Operating system: Linux PHP version: 7.1.4RC1 Package: PCRE related Bug Type: Bug Bug description:Sporadi Description: ------------ Patch ebfd93f725eb9b9cfadbbde98047efe76f658da6 introduced an issue that is both hard to debug and reproduce. FPM processes start to crash in completely random places (mostly pointing to the executor code), all FPM children at once. Unfortunately, I don't have a reproduce case and I don't know of any reliable way to reproduce it, other than to start FPM on production server under a heavy load and leave it for a while. I've spent a lot of time debugging it and have found that the problem goes away as soon as I revert ebfd93f725eb9b9cfadbbde98047efe76f658da6. After looking at the patch closely, I've noticed that the patch changes one tricky part of the code managing refcount of the string stored in the cache. In the new version that part is gone and reverting this part of the patch fixes the issue, see attached patch. Test script: --------------- . Expected result: ---------------- No crashes. Actual result: -------------- Sporadic FPM segfaults. -- Edit bug report at https://bugs.php.net/bug.php?id=74403&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=74403&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=74403&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=74403&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=74403&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=74403&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=74403&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=74403&r=needscript Try newer version: https://bugs.php.net/fix.php?id=74403&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=74403&r=support Expected behavior: https://bugs.php.net/fix.php?id=74403&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=74403&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=74403&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=74403&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=74403&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=74403&r=dst IIS Stability: https://bugs.php.net/fix.php?id=74403&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=74403&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=74403&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=74403&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=74403&r=mysqlcfg