Bug #60078 [NEW]: SIGSEGV in xhprof.c

From: Operating system: - PHP version: Irrelevant Package: xhprof Bug Type: Bug Bug description:SIGSEGV in xhprof.c Description: ------------ I'll try to be as precise as possible : This happens in a special case that can be reproduced 100%, but I cannot provide a test script (it is using 20MB of closed customer code). This happens only whith xhprof_enable(). No problem is encountered when the module is just loaded with no call to xhprof_enable() In latest clone from git (commit a6bae51236 for file xhprof.c) Program received signal SIGSEGV, Segmentation fault. 0x00007ffff3575f49 in hp_mode_shared_endfn_cb (top=0xef0210, symbol=<value optimized out>) at /usr/src/xhprof/extension/xhprof.c:1553 bt #0 hp_mode_shared_endfn_cb (top=0xef0210, symbol=<value optimized out>) at /usr/src/xhprof/extension/xhprof.c:1553 #1 0x00007ffff357609e in hp_mode_hier_endfn_cb (entries=<value optimized out>) at /usr/src/xhprof/extension/xhprof.c:1573 #2 0x00007ffff3576e66 in hp_compile_file (file_handle=<value optimized out>, type=8) at /usr/src/xhprof/extension/xhprof.c:1721 #3 0x00000000007218a4 in ?? () #4 0x000000000071f294 in execute () #5 0x00000000006faf7b in zend_execute_scripts () #6 0x00000000006b573a in php_execute_script () #7 0x0000000000772287 in main () Ok so problem is in the function "hp_mode_shared_endfn_cb" Let's try to see what is the value of each variable here : print /f hp_globals.cpu_frequencies[hp_globals.cur_cpu_id] Cannot access memory at address 0x0 ok so problem is in this expression. print hp_globals.cpu_frequencies $8 = (double *) 0x0 (gdb) print /f hp_globals.cur_cpu_id $9 = 0 Ok so I can see that hp_globals.cpu_frequencies equals NULL (right ?), and we attempt to access it as an array. I read the source code quickly, and I can see that this array should be filled at some point. Seems it is not. I made a dirty patch just to avoid the SIGSEGV, but all my timings in xhprof reports are inaccurate now. -- Edit bug report at https://bugs.php.net/bug.php?id=60078&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=60078&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=60078&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=60078&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=60078&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=60078&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=60078&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=60078&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=60078&r=needscript Try newer version: https://bugs.php.net/fix.php?id=60078&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=60078&r=support Expected behavior: https://bugs.php.net/fix.php?id=60078&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=60078&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=60078&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=60078&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=60078&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=60078&r=dst IIS Stability: https://bugs.php.net/fix.php?id=60078&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=60078&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=60078&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=60078&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=60078&r=mysqlcfg