Question

我的应用程序中存在一个在远程服务器上运行的错误。执行几个小时后，应用程序将获得SIGSEGV并终止。

我想通过ssh使用gdb调试我的远程应用程序，所以当程序获得SIGSEGV时gdb将停止并允许我查看发生了什么，但我不能将ssh会话留给连接的服务器。我正试图跑：

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保持运行
以后如何重新连接？

关闭终端时，gdb上的

strace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 +++

Answer 1

你可以使用＆＃39; screen＆＃39;之类的东西，如果你从它上面分离它会继续运行（CTRL-a d），然后你可以稍后用＆＃39; screen -r＆＃39;重新连接。

或者您可以使用程序名称和PID重新附加gdb，例如＆＃39; gdb my_app 1234＆＃39;，其中数字1234必须由正确的PID替换。

Answer 2

打开核心转储：

ulimit -c unlimited

然后执行你的程序（导致seg故障），你会看到“Segmentation fault（core dumped）”，当进程崩溃时系统会保存转储，你就可以在需要的时候进行分析，即使你失去联系。

然后启动gdb -c core

使用gdb调试进程并关闭终端

2 个答案: