#20985 [Com]: heavy load = Segmentation fault

ID: 20985 Comment by: jfl@eksperten.dk Reported By: jfl@eksperten.dk Status: Feedback Bug Type: Reproducible crash Operating System: Redhat Linux 7.3 & 8 PHP Version: 4.3.0RC3 New Comment: I'll now start testing Php-4.3.0RC3 Previous Comments: ------------------------------------------------------------------------ [2002-12-14 13:51:02] jfl@eksperten.dk This is what I get every time with Php 4.2.3 compiled into Apache. More info @ http://test.webalogic.net/bugs/ I think the bug is happening when Apache is trying to kill children, as the SIGSEGV is happening when the stress tool is finished. (gdb) run -X Starting program: /usr/local/apache/bin/httpd -X Program received signal SIGSEGV, Segmentation fault. 0x4207c46c in memcpy () from /lib/i686/libc.so.6 (gdb) bt #0 0x4207c46c in memcpy () from /lib/i686/libc.so.6 #1 0x081041d0 in _mem_block_check () #2 0x08104197 in _mem_block_check () #3 0x081034a1 in _efree () #4 0x0811283c in _zval_dtor () #5 0x08109bac in free_zend_constant () #6 0x08118c29 in zend_hash_del_key_or_index () #7 0x081194a6 in zend_hash_reverse_apply () #8 0x08109fb4 in clean_non_persistent_constants () #9 0x0810a780 in shutdown_executor () #10 0x0811387f in zend_deactivate () #11 0x08078500 in php_request_shutdown () #12 0x0811f192 in apache_php_module_main () #13 0x080761cc in php_restore_umask () #14 0x08076237 in php_restore_umask () #15 0x08140990 in ap_invoke_handler () #16 0x08154d86 in ap_some_auth_required () #17 0x08154de6 in ap_process_request () #18 0x0814c0aa in ap_child_terminate () #19 0x0814c24a in ap_child_terminate () #20 0x0814c3b1 in ap_child_terminate () #21 0x0814c9de in ap_child_terminate () #22 0x0814d1fc in main () ---Type <return> to continue, or q <return> to quit--- #23 0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6 (gdb) frame 5 #5 0x08109bac in free_zend_constant () (gdb) list 1 <unknown>: No such file or directory. in <unknown> (gdb) p The history is empty. (gdb) ------------------------------------------------------------------------ [2002-12-13 19:14:00] jfl@eksperten.dk If php is built into apache, where should I then be able to find a core file? apache is here: /usr/local/apache/bin ------------------------------------------------------------------------ [2002-12-13 16:53:39] iliaa@php.net Go to the php directory, inside that directory edit a file called config.nice, one line above the line, which contains "$@" add the following line: '--enable-debug' \ now do: rm config.cache; make clean; ./config.nice; make; make install You've now compiled & installed PHP that contains debugging symbols, when a crash occurs you should be able to see more detailed information when analyzing core files generated due to crash in PHP. To see data at a certain step use gdb command such as frame 5, which will take you to a particular frame, list command, which will show the source code at this point and then p command to print the values of various variables & pointers. ------------------------------------------------------------------------ [2002-12-13 16:40:34] jfl@eksperten.dk > Could you please compile your PHP with --enable-debug I have done so. > If you are able to do that then go the step #5 > (free_zend_constant) and see what data the various > pointers contains. > I am especially interested in seeing what constant is > being freed and if it is the same one everytime. Could you instruct me on how to do this? My knowledge only covers compiling and the information from here: http://bugs.php.net/bugs-generating-backtrace.php ------------------------------------------------------------------------ [2002-12-13 09:56:09] iliaa@php.net Could you please compile your PHP with --enable-debug, this will make you backtrace contain a lot more information. If you are able to do that then go the step #5 (free_zend_constant) and see what data the various pointers contains. I am especially interested in seeing what constant is being freed and if it is the same one everytime. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/20985 -- Edit this bug report at http://bugs.php.net/?id=20985&edit=1