backtrace, 콜스택 보기
(gdb) bt
#0 odbc_stmt_param_hook (stmt=0x10a22e0, param=0x7fffffffa660, event_type=PDO_PARAM_EVT_NORMALIZE) at /home/reznoa/work/php-5.3.21/ext/pdo_odbc/odbc_stmt.c:279
#1 0x00000000005d0b87 in really_register_bound_param (param=0x7fffffffa660, stmt=0x10a22e0, is_param=1) at /home/reznoa/work/php-5.3.21/ext/pdo/pdo_stmt.c:386
#2 0x00000000005d4f56 in zim_PDOStatement_bindValue (ht=3, return_value=0x10a9618, return_value_ptr=0x0, this_ptr=0x10a9528, return_value_used=0)
at /home/reznoa/work/php-5.3.21/ext/pdo/pdo_stmt.c:1656
#3 0x0000000000831a2a in zend_do_fcall_common_helper_SPEC (execute_data=0x7ffff7ec65d8) at /home/reznoa/work/php-5.3.21/Zend/zend_vm_execute.h:320
#4 0x00000000008320b1 in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7ffff7ec65d8) at /home/reznoa/work/php-5.3.21/Zend/zend_vm_execute.h:425
#5 0x0000000000830f03 in execute (op_array=0x10a4d40) at /home/reznoa/work/php-5.3.21/Zend/zend_vm_execute.h:107
breakpoint와 watchpoint
목록 보기
(gdb) info breakpoints
Num Type Disp Enb Address What
1 breakpoint keep y 0x00007ffff629a3d0 in SQLDescribeParam at SQLDescribeParam.c:214
2 hw watchpoint keep y *0x1103610
(gdb) info b
Num Type Disp Enb Address What
1 breakpoint keep y 0x00007ffff629a3d0 in SQLDescribeParam at SQLDescribeParam.c:214
2 hw watchpoint keep y *0x1103610
(gdb) i b
Num Type Disp Enb Address What
1 breakpoint keep y 0x00007ffff629a3d0 in SQLDescribeParam at SQLDescribeParam.c:214
2 hw watchpoint keep y *0x1103610
(gdb) info watchpoints
Num Type Disp Enb Address What
2 hw watchpoint keep y *0x1103610
(gdb) i wat
Num Type Disp Enb Address What
2 hw watchpoint keep y *0x1103610
특정 주소에 읽고 쓰는것 감시
- watch: 쓸 때 중단 (단, 값이 바뀔때만)
- rwatch: 읽을 때 중단
- awatch: 읽거나 쓸 때 중단
0x00007ffff629eed5 in SQLExecute (statement_handle=0x11f3720) at SQLExecute.c:324
324 statement -> state = STATE_S4;
(gdb) p &(statement->state)
$66 = (int *) 0x11f3b30
(gdb) watch *(int *)0x11f3b30
(gdb) c
Continuing.
Hardware watchpoint 25: *(int *)0x11f3b30
Old value = 3
New value = 4
시그널 제어
gdb는 기본적으로 모든 시그널을 받을 때마다 멈추는데, 멀티 스레드, 멀티 프로세스 프로그램에서 발생하는 SIGPIPE 등은 무시해도 되는 경우가 있다. 그런 경우엔 handle 명령을 사용한다.
(gdb) handle SIGPIPE nostop
(gdb) handle SIGPIPE noprint
지정할 수 있는 동작은 다음과 같다:
| 동작 | 비동작 | 설명 |
|---|---|---|
| stop | nostop | 멈추고 디버거로 들어갈지 여부 |
| noprint | 출력 여부 | |
| pass | nopass | 프로그램에서 인식할 수 있게 신호를 전달할지 여부 |
| ignore | noignore | pass의 반대 (ignore = nopass, noignore = pass) |
