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