Question

有没有办法获取正在运行的应用程序Unix的指令指针？

我有一个正在运行的进程（C ++），想要获取它的当前位置，然后在GDB（在另一台机器上）将位置映射到源位置（'list'命令）。

Answer 1

在Linux上，有/proc/[pid]/stat。来自"man proc"：

 stat   Status information about the process. This is used by
       ps(1). It is defined in /usr/src/linux/fs/proc/array.c.
       ...
       kstkeip %lu
       The current EIP (instruction pointer).

AFAICT，输出的第29个字段对应于进程的当前指令指针。例如：

gdb date
GNU gdb Red Hat Linux (6.0post-0.20040223.20rh)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu"...(no debugging symbols found)...Using host libthread_db library "/lib64/tls/libthread_db.so.1".

(gdb) set stop-on-solib-events 1
(gdb) run
(no debugging symbols found)...(no debugging symbols found)...(no debugging symbols found)...[Thread debugging using libthread_db enabled]
[New Thread 182896391360 (LWP 27968)]
(no debugging symbols found)...Stopped due to shared library event
(gdb) c
[Switching to Thread 182896391360 (LWP 27968)]
Stopped due to shared library event
(gdb) where
#0  0x00000036b060bb20 in _dl_debug_state_internal () from /lib64/ld-linux-x86-64.so.2
#1  0x00000036b060b51c in _dl_init_internal () from /lib64/ld-linux-x86-64.so.2
#2  0x00000036b0600f72 in _dl_start_user () from /lib64/ld-linux-x86-64.so.2
#3  0x0000000000000001 in ?? ()
#4  0x0000007fbff62728 in ?? ()
#5  0x0000000000000000 in ?? ()
(gdb) shell cat /proc/27968/stat
27968 (date) T 27839 27968 8955 34817 27839 4194304 42 0 330 0 0 0 0 0 18 0 0 0 1881668573 6144000 78 18446744073709551615 4194304 4234416 548680739552 18446744073709551615 234887363360 0 0 0 0 18446744071563322838 0 0 17 0 0 0 0 0 0 0
(gdb) p/a 234887363360  <--- the value of 29th field
$1 = 0x36b060bb20 <_dl_debug_state_internal>

Answer 2

可以使用以下代码在Linux上检索指令指针：

pid_t traced_process;
struct user_regs_struct regs;

ptrace(PTRACE_ATTACH, traced_process, NULL, NULL);
ptrace(PTRACE_GETREGS, traced_process, NULL, &regs);

printf("EIP: %lx\n", regs.eip);

Answer 3

您需要暂时停止进程或线程以获取其当前指令指针。您可以通过使用ptrace()或（在HP-UX上）ttrace()附加到进程并访问寄存器来完成此操作。

Answer 4

如果你正在使用gdb，你可以简单地将自己附加到这样一个正在运行的进程：

gdb program 1234

其中program是您正在调试的可执行文件的名称，1234是PID。然后，您可以使用gdb的所有工具来调试该过程。

在Unix上获取运行应用程序的指令指针

4 个答案: