(gdb) bt
#0  process_info (r=0x7f01039b7088, errtype=<value optimized out>) at mod_manager.c:1150
#1  0x00007f00fd15b44a in manager_handler (r=0x7f01039b7088) at mod_manager.c:2705
#2  0x00007f0102927640 in ap_run_handler (r=0x7f01039b7088) at /usr/src/debug/httpd-2.2.15/server/config.c:158
#3  0x00007f010292aefe in ap_invoke_handler (r=0x7f01039b7088) at /usr/src/debug/httpd-2.2.15/server/config.c:376
#4  0x00007f0102936300 in ap_process_request (r=0x7f01039b7088) at /usr/src/debug/httpd-2.2.15/modules/http/http_request.c:282
#5  0x00007f0102933178 in ap_process_http_connection (c=0x7f00f00ebba0) at /usr/src/debug/httpd-2.2.15/modules/http/http_core.c:190
#6  0x00007f010292f148 in ap_run_process_connection (c=0x7f00f00ebba0) at /usr/src/debug/httpd-2.2.15/server/connection.c:43
#7  0x00007f010293c052 in process_socket (thd=0x7f010393a1b0, dummy=<value optimized out>) at /usr/src/debug/httpd-2.2.15/server/mpm/worker/worker.c:544
#8  worker_thread (thd=0x7f010393a1b0, dummy=<value optimized out>) at /usr/src/debug/httpd-2.2.15/server/mpm/worker/worker.c:894
#9  0x00007f01011d19d1 in ?? ()
#10 0x00007f00d8dda700 in ?? ()
#11 0x0000000000000000 in ?? ()

(gdb) disassemble
    ...
   0x00007f00fd1558f4 <+452>:   mov    0x58(%rsp),%rax                                                        
   0x00007f00fd1558f9 <+457>:   lea    0x82f0(%rip),%rsi        # 0x7f00fd15dbf0                                                         
   0x00007f00fd155900 <+464>:   mov    %r13,%rdi                                                                              
   0x00007f00fd155903 <+467>:   add    0x138(%rax),%rax                                                                                  
=> 0x00007f00fd15590a <+474>:   mov    0xc0(%rax),%r9                                                                       

(gdb) x/gx $rsp+0x58                                                                                                                     
0x7f00d8dd9b98: 0x00007f01028d4e60                                  
(gdb) x/gx 0x00007f01028d4e60+0x138                                 
0x7f01028d4f98: 0x0000000000000140                                  
(gdb) print/x 0x00007f01028d4e60+0x140                                                                                                   
$1 = 0x7f01028d4fa0
(gdb) # therefore, rax should be 0x7f01028d4fa0, but in fact:
(gdb) info registers rax
rax            0xfe01a299c750   279282976409424
(gdb)