Show a memory map of the process being attached by GDB

You can show a memory map of a program being attached by info proc map. The following illustrates an example with 'cat' command.

'cat' command w/o arguments continue to wait for standard input. To operate GDB in that case, CTRL + C is typed in the following.

$ gdb /bin/cat
[skip]
(gdb) run
Starting program: /bin/cat 
^C　<= Interrupt by typing CTRL + C
Program received signal SIGINT, Interrupt.
0x00007ffff7afe6a0 in __read_nocancel () at ../sysdeps/unix/syscall-template.S:81
81      ../sysdeps/unix/syscall-template.S: No such file or directory.
(gdb) info proc map
process 31692
Mapped address spaces:

          Start Addr           End Addr       Size     Offset objfile
            0x400000           0x40b000     0xb000        0x0 /bin/cat
            0x60a000           0x60b000     0x1000     0xa000 /bin/cat
            0x60b000           0x60c000     0x1000     0xb000 /bin/cat
            0x60c000           0x62d000    0x21000        0x0 [heap]
      0x7ffff7a12000     0x7ffff7bcf000   0x1bd000        0x0 /lib/x86_64-linux-gnu/libc-2.17.so
      0x7ffff7bcf000     0x7ffff7dcf000   0x200000   0x1bd000 /lib/x86_64-linux-gnu/libc-2.17.so
      0x7ffff7dcf000     0x7ffff7dd3000     0x4000   0x1bd000 /lib/x86_64-linux-gnu/libc-2.17.so
      0x7ffff7dd3000     0x7ffff7dd5000     0x2000   0x1c1000 /lib/x86_64-linux-gnu/libc-2.17.so
      0x7ffff7dd5000     0x7ffff7dda000     0x5000        0x0 
      0x7ffff7dda000     0x7ffff7dfd000    0x23000        0x0 /lib/x86_64-linux-gnu/ld-2.17.so
      0x7ffff7fcc000     0x7ffff7fcf000     0x3000        0x0 
      0x7ffff7ff8000     0x7ffff7ffa000     0x2000        0x0 
      0x7ffff7ffa000     0x7ffff7ffc000     0x2000        0x0 [vdso]
      0x7ffff7ffc000     0x7ffff7ffd000     0x1000    0x22000 /lib/x86_64-linux-gnu/ld-2.17.so
      0x7ffff7ffd000     0x7ffff7fff000     0x2000    0x23000 /lib/x86_64-linux-gnu/ld-2.17.so
      0x7ffffffde000     0x7ffffffff000    0x21000        0x0 [stack]
  0xffffffffff600000 0xffffffffff601000     0x1000        0x0 [vsyscall]

There is a similar command info shared. This only shows mapped shared libraries. The column 'Syms Read' indicates whethere the debug symbols has been read.

(gdb) info shared
From                To                  Syms Read   Shared Object Library
0x00007ffff7ddaaa0  0x00007ffff7df5439  Yes         /lib64/ld-linux-x86-64.so.2
0x00007ffff7a313c0  0x00007ffff7b7c39f  Yes         /lib/x86_64-linux-gnu/libc.so.6