请问有高手在debain/ubuntu调试apache的经验吗?

[tarside]

root@debian:/tmp# gdb apache2
GNU gdb (GDB) 7.0.1-debian
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...

warning: The current binary is a PIE (Position Independent Executable), which
GDB does NOT currently support. Most debugger features will fail if used
in this session.

Reading symbols from /usr/sbin/apache2...done.
(gdb) b ap_process_request
Breakpoint 1 at 0x50374: file /home/tarside/source/apache2-2.2.16/apache2-2.2.16/modules/http/http_request.c, line 276.
(gdb) b main
Breakpoint 2 at 0x22aee: file /home/tarside/source/apache2-2.2.16/apache2-2.2.16/server/main.c, line 452.
(gdb) set args -X
(gdb) run
Starting program: /usr/sbin/apache2 -X
Warning:
Cannot insert breakpoint 1.
Error accessing memory address 0x50362: Input/output error.
Cannot insert breakpoint 2.
Error accessing memory address 0x22ad9: Input/output error.
(gdb)