加载可执行程序和core dump文件

#include <stdio.h>

int main(void) {
        int *p = NULL;
        printf("hello world\n");
        *p = 0;
        return 0;
}

技巧

例子程序访问了一个空指针，所以程序会crash并产生core dump文件。用gdb调试core dump文件，通常用这个命令形式：“gdb path/to/the/executable path/to/the/coredump”，然后gdb会显示程序crash的位置：

bash-3.2# gdb -q /data/nan/a /var/core/core.a.22268.1402638140
Reading symbols from /data/nan/a...done.
[New LWP 1]
[Thread debugging using libthread_db enabled]
[New Thread 1 (LWP 1)]
Core was generated by `./a'.
Program terminated with signal 11, Segmentation fault.
#0  0x0000000000400cdb in main () at a.c:6
6               *p = 0;

有时我们想在gdb启动后，动态加载可执行程序和core dump文件，这时可以用“file”和“core”（core-file命令缩写）命令。“file”命令用来读取可执行文件的符号表信息，而“core”命令则是指定core dump文件的位置：

bash-3.2# gdb -q
(gdb) file /data/nan/a
Reading symbols from /data/nan/a...done.
(gdb) core /var/core/core.a.22268.1402638140
[New LWP 1]
[Thread debugging using libthread_db enabled]
[New Thread 1 (LWP 1)]
Core was generated by `./a'.
Program terminated with signal 11, Segmentation fault.
#0  0x0000000000400cdb in main () at a.c:6
6               *p = 0;

可以看到gdb同样显示程序crash的位置。

这两个命令可参见 gdb手册