gdb調試動態鏈接 _start位置

#include <stdio.h>

int main()
{
        int a = 0x55;
        printf("%d hellow world!\n", a);
        while (1) {

        };
        return a;
}

動態鏈接文件的調試，

gcc -g -o test test.c

因爲動態鏈接方式，readelf 到的entry point並不是真正的入口點

Magic:   7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF64
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           Advanced Micro Devices X86-64
  Version:                           0x1
  Entry point address:               0x540
  Start of program headers:          64 (bytes into file)
  Start of section headers:          8584 (bytes into file)
  Flags:                             0x0
  Size of this header:               64 (bytes)
  Size of program headers:           56 (bytes)
  Number of program headers:         9
  Size of section headers:           64 (bytes)
  Number of section headers:         34
  Section header string table index: 33

運行之後，查看 cat /proc/xxx/maps

xxxxxx@pc ~ $ cat /proc/19970/maps
55e468aa3000-55e468aa4000 r-xp 00000000 08:01 1835098                    /home/guozheng.li/test
55e468ca3000-55e468ca4000 r--p 00000000 08:01 1835098                    /home/guozheng.li/test
55e468ca4000-55e468ca5000 rw-p 00001000 08:01 1835098                    /home/guozheng.li/test
55e46936b000-55e46938c000 rw-p 00000000 00:00 0                          [heap]
7f2ced069000-7f2ced250000 r-xp 00000000 08:01 8786634                    /lib/x86_64-linux-gnu/libc-2.27.so
7f2ced250000-7f2ced450000 ---p 001e7000 08:01 8786634                    /lib/x86_64-linux-gnu/libc-2.27.so
7f2ced450000-7f2ced454000 r--p 001e7000 08:01 8786634                    /lib/x86_64-linux-gnu/libc-2.27.so
7f2ced454000-7f2ced456000 rw-p 001eb000 08:01 8786634                    /lib/x86_64-linux-gnu/libc-2.27.so
7f2ced456000-7f2ced45a000 rw-p 00000000 00:00 0
7f2ced45a000-7f2ced481000 r-xp 00000000 08:01 8786606                    /lib/x86_64-linux-gnu/ld-2.27.so
7f2ced63d000-7f2ced63f000 rw-p 00000000 00:00 0
7f2ced681000-7f2ced682000 r--p 00027000 08:01 8786606                    /lib/x86_64-linux-gnu/ld-2.27.so
7f2ced682000-7f2ced683000 rw-p 00028000 08:01 8786606                    /lib/x86_64-linux-gnu/ld-2.27.so
7f2ced683000-7f2ced684000 rw-p 00000000 00:00 0
7fff0b379000-7fff0b39b000 rw-p 00000000 00:00 0                          [stack]
7fff0b3b8000-7fff0b3bb000 r--p 00000000 00:00 0                          [vvar]
7fff0b3bb000-7fff0b3bd000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]

開始進入gdb

地址： 0x7ffff7dd6093並沒有加載到繼承的地址空間，應該是放到了加載器的空間裏面，此處待補充