Bug #70891 [Opn->Fbk]: opcache+exception = segfault in some cases

Edit report at https://bugs.php.net/bug.php?id=70891&edit=1 ID: 70891 Updated by: cmb@php.net Reported by: s dot chernomorets at gmail dot com Summary: opcache+exception = segfault in some cases -Status: Open +Status: Feedback Type: Bug Package: opcache Operating System: centos5 PHP Version: 5.6.15 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: Can you still reproduce this segfault with any of the actively supported PHP versions[1]? [1] <https://www.php.net/supported-versions.php> Previous Comments: ------------------------------------------------------------------------ [2015-11-11 16:18:21] s dot chernomorets at gmail dot com opcache.optimization_level="0xffffffef" solves problem - no segfault According to http://stackoverflow.com/questions/21181045/php-opcache-optimization-levels-what-are-they it means: bit 4 - pass 5: block optimization (the most expensive optimization pass which perform many different optimization patterns based on CFG - control flow graph) ------------------------------------------------------------------------ [2015-11-11 14:28:09] s dot chernomorets at gmail dot com Description: ------------ When opcache disabled - no segfaults. I have tried last php version from https://github.com/php/php-src/commits/PHP-5.6 (1a1240) I cannot reproduce segfault on small script, so code bellow is enough approximate (I know it very-very ugly code, but it works on php5.3+APC). On my project segfault reproduces in 100% cases on the first HTTP-request. It seems, opcache broke cache of compiled scripts: when I move source code of function sql_assoc above or below of other function - no problem. When I return function on old place - segfault return also. Test script: --------------- //WARN: Code is very approximate! It uses PDO. try { sql_assoc("SELECT which throw exception"); }catch(Exception $e) { // we MUST catch exception here, but process killed by SIGSEGV } function sql_assoc($sql, $link = null) { return sql_fetch(sql_query($sql, $link)); } function sql_query($sql, $link = null) { return sql_get_connect($link)->query($sql); } function sql_get_connect($link = null) { if ($OurPDO = DBConnector::instance()->getConnection($link)) { return $OurPDO; } else { throw new Exception('...'); } } function sql_fetch($result, $fetch_type = PDO::FETCH_ASSOC) { sql_check_result($result); return $result->fetch($fetch_type); } function sql_check_result($result) { if (!($result instanceof OurPDOStatement)) { throw new Exception('...'); } } Expected result: ---------------- Catched PDOException Actual result: -------------- Segmentation fault $ gdb -x gdb.run /usr/sbin/httpd GNU gdb (GDB) CentOS (7.0.1-45.el5.centos) This GDB was configured as "x86_64-redhat-linux-gnu". Reading symbols from /usr/sbin/httpd...(no debugging symbols found)...done. warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffff7fad000 [Thread debugging using libthread_db enabled] Program received signal SIGSEGV, Segmentation fault. 0x00007ffff36b9cbd in zend_mm_check_ptr (heap=0x7ffff842ee80, ptr=0x600000000, silent=1, __zend_filename=0x7ffff3ce9bc8 "/home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h", __zend_lineno=1218, __zend_orig_filename=0x0, __zend_orig_lineno=0) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_alloc.c:1384 1384 if (p->info._size != ZEND_MM_NEXT_BLOCK(p)->info._prev) { (gdb) (gdb) bt #0 0x00007ffff36b9cbd in zend_mm_check_ptr (heap=0x7ffff842ee80, ptr=0x600000000, silent=1, __zend_filename=0x7ffff3ce9bc8 "/home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h", __zend_lineno=1218, __zend_orig_filename=0x0, __zend_orig_lineno=0) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_alloc.c:1384 #1 0x00007ffff36bbb79 in _zend_mm_free_int (heap=0x7ffff842ee80, p=0x600000000, __zend_filename=0x7ffff3ce9bc8 "/home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h", __zend_lineno=1218, __zend_orig_filename=0x0, __zend_orig_lineno=0) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_alloc.c:2068 #2 0x00007ffff36bd260 in _efree (ptr=0x600000000, __zend_filename=0x7ffff3ce9bc8 "/home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h", __zend_lineno=1218, __zend_orig_filename=0x0, __zend_orig_lineno=0) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_alloc.c:2440 #3 0x00007ffff373d66e in ZEND_HANDLE_EXCEPTION_SPEC_HANDLER (execute_data=0x7ffff7f21a98) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:1218 #4 0x00007ffff3739c97 in execute_ex (execute_data=0x7ffff7f21a98) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:363 #5 0x00007ffff3739d20 in zend_execute (op_array=0x7ffff924dc60) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:388 #6 0x00007ffff36e1858 in zend_call_function (fci=0x7fffffffb930, fci_cache=0x7fffffffb900) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_execute_API.c:829 #7 0x00007ffff3442580 in zim_reflection_method_invokeArgs (ht=2, return_value=0x7ffff959d998, return_value_ptr=0x7ffff7f20cd0, this_ptr=0x7ffff958fea8, return_value_used=0) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/ext/reflection/php_reflection.c:3079 #8 0x00007ffff373a805 in zend_do_fcall_common_helper_SPEC (execute_data=0x7ffff7f20ce8) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:558 #9 0x00007ffff373b51c in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7ffff7f20ce8) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:693 #10 0x00007ffff3739c97 in execute_ex (execute_data=0x7ffff7f20ce8) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:363 #11 0x00007ffff3739d20 in zend_execute (op_array=0x7ffff8b38a38) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:388 #12 0x00007ffff36f7c1d in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend.c:1341 #13 0x00007ffff365dd05 in php_execute_script (primary_file=0x7fffffffe090) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/main/main.c:2597 #14 0x00007ffff37a7d8f in php_handler (r=0x7ffff8775940) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/sapi/apache2handler/sapi_apache2.c:667 #15 0x00007ffff7fdaf4a in ap_run_handler () #16 0x00007ffff7fde3d8 in ap_invoke_handler () #17 0x00007ffff7fe8d3a in ap_internal_redirect () #18 0x00007fffecd94c70 in ap_make_dirstr_parent () from /home/chernomorets/test-httpd/modules/mod_rewrite.so #19 0x00007ffff7fdaf4a in ap_run_handler () #20 0x00007ffff7fde3d8 in ap_invoke_handler () #21 0x00007ffff7fe8ee8 in ap_process_request () #22 0x00007ffff7fe60d0 in ?? () #23 0x00007ffff7fe21d2 in ap_run_process_connection () #24 0x00007ffff7fed389 in ?? () #25 0x00007ffff7fed589 in ?? () #26 0x00007ffff7fee0a7 in ap_mpm_run () #27 0x00007ffff7fc8058 in main () (gdb) list 1379 return zend_mm_check_ptr(heap, ptr, 0 ZEND_FILE_LINE_RELAY_CC ZEND_FILE_LINE_ORIG_RELAY_CC); 1380 } 1381 } 1382 #endif 1383 1384 if (p->info._size != ZEND_MM_NEXT_BLOCK(p)->info._prev) { 1385 if (!silent) { 1386 zend_debug_alloc_output("Invalid pointer: ((size="PTR_FMT") != (next.prev="PTR_FMT"))\n", p->info._size, ZEND_MM_NEXT_BLOCK(p)->info._prev); 1387 had_problems = 1; 1388 } else { (gdb) p ptr $1 = (void *) 0x600000000 (gdb) f 3 #3 0x00007ffff373d66e in ZEND_HANDLE_EXCEPTION_SPEC_HANDLER (execute_data=0x7ffff7f21a98) at /home/chernomorets/rpmbuild/BUILD/php-5.6.15.1/Zend/zend_vm_execute.h:1218 1218 efree((char *) call->fbc->common.function_name); (gdb) p call->fbc->common.function_name $2 = 0x600000000 <Address 0x600000000 out of bounds> (gdb) p call->fbc->common $3 = {type = 0 '\000', function_name = 0x600000000 <Address 0x600000000 out of bounds>, scope = 0x7ffff9a68901, fn_flags = 3391487952, prototype = 0x7ffff879b590, num_args = 4159838832, required_num_args = 32767, arg_info = 0x7ffff9155670} (gdb) cat gdb.run run -X -f apache.conf ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70891&edit=1