1

我的应用程序中有一个在远程服务器上运行的错误。执行几个小时后，应用程序获得一个 SIGSEGV 并终止。

我想通过 ssh 使用 gdb 调试我的远程应用程序，因此当程序获取 SIGSEGV 时，gdb 将停止并允许我查看发生了什么，但我无法将 ssh 会话留给连接的服务器。我正在尝试运行：

setsid gdb my_app

但是当我关闭 ssh 终端时，gdb 和我的应用程序会立即终止。

我的问题：

  • 关闭终端时如何让 gdb 运行
  • 以后如何重新连接？

strace在关闭终端的那一刻在 gdb 上显示：

read(0, 0x7fff0532895f, 1)              = -1 EIO (Input/output error)
ioctl(0, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS, 0x7fff05328930) = -1 EIO (Input/output error)
ioctl(0, SNDCTL_TMR_STOP or SNDRV_TIMER_IOCTL_GINFO or TCSETSW, {B38400 opost isig -icanon -echo ...}) = -1 EIO (Input/output error)
rt_sigaction(SIGINT, {0x5b3550, [INT], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGTERM, {0x5b3710, [TERM], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGHUP, {0x5b33d0, [HUP], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGQUIT, {0x5b33f0, [QUIT], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGALRM, {SIG_DFL, [], SA_RESTORER, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGTSTP, {SIG_DFL, [TSTP], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGTTOU, {SIG_DFL, [], SA_RESTORER, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGTTIN, {SIG_DFL, [], SA_RESTORER, 0x7fa0fbaa0c90}, {0x7fa0fce86ac0, [], SA_RESTORER, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGWINCH, {0x4efb70, [], SA_RESTORER, 0x7fa0fbaa0c90}, {0x7fa0fce86160, [], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGTSTP, {0x5b3410, [TSTP], SA_RESTORER|SA_RESTART, 0x7fa0fae70da0}, {SIG_DFL, [TSTP], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, 8) = 0
ioctl(0, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS, 0x7fff053288e0) = -1 EIO (Input/output error)
write(1, "quit\n", 5)                   = -1 EIO (Input/output error)
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigaction(SIGINT, {0x5b3550, [INT], SA_RESTORER|SA_RESTART, 0x7fa0fae70da0}, {0x5b3550, [INT], SA_RESTORER|SA_RESTART, 0x7fa0fbaa0c90}, 8) = 0
rt_sigaction(SIGINT, {SIG_DFL, [], SA_RESTORER, 0x7fa0fbaa0c90}, {0x5b3550, [INT], SA_RESTORER|SA_RESTART, 0x7fa0fae70da0}, 8) = 0
exit_group(0)                           = ?
+++ exited with 0 +++
4

2 回答 2

1

您可以使用“screen”之类的东西，如果您从它分离（CTRL-a d）它将继续运行，然后您可以稍后使用“screen -r”重新连接。

或者，您可以使用程序名称和 PID 重新附加 gdb，例如“gdb my_app 1234”，其中数字 1234 必须替换为正确的 PID。

于 2014-12-21T12:13:25.087 回答
1

打开核心转储：

ulimit -c unlimited

然后执行你的程序（导致seg fault），你应该看到“Segmentation fault（core dumped）”，当进程崩溃时系统会保存一个dump，你可以在需要的时候分析它，即使你失去了连接。

然后启动gdb -c core

于 2014-12-21T14:14:35.353 回答