segmentation fault

auditory@ubuntu:~$ ./a.out
세그멘테이션 오류
auditory@ubuntu:~$ ldd ./a.out
        linux-vdso.so.1 =>  (0x00007fffcf9ff000)
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007fc552cc6000)
        libm.so.6 => /lib/libm.so.6 (0x00007fc552a43000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00007fc55282c000)
        libc.so.6 => /lib/libc.so.6 (0x00007fc5524a9000)
        /lib64/ld-linux-x86-64.so.2 (0x00007fc552fe0000)
auditory@ubuntu:~$ gdb ./a.out
GNU gdb (GDB) 7.2-ubuntu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/auditory/a.out...done.
(gdb) break main
Breakpoint 1 at 0x404c51: file main.cpp, line 36.
(gdb) run
Starting program: /home/auditory/a.out
 
Breakpoint 1, main (argc=1, argv=0x7fffffffe308) at main.cpp:36
36              fprintf( stderr, "end\n" );
(gdb) info sharedlibrary
From                To                  Syms Read   Shared Object Library
0x00007ffff7ddcaf0  0x00007ffff7df5a64  Yes (*)     /lib64/ld-linux-x86-64.so.2
0x00007ffff7b2dd60  0x00007ffff7b98916  Yes (*)     /usr/lib/libstdc++.so.6
0x00007ffff7856ef0  0x00007ffff78972d8  Yes (*)     /lib/libm.so.6
0x00007ffff763f8b0  0x00007ffff764efe8  Yes (*)     /lib/libgcc_s.so.1
0x00007ffff72d8a00  0x00007ffff73eb920  Yes (*)     /lib/libc.so.6
(*): Shared library is missing debugging information.
(gdb) l
31      }
32
33      int
34      main(int argc, char** argv)
35      {
36              fprintf( stderr, "end\n" );
37              return 0;
38      }
(gdb) continue
Continuing.
end
 
Program exited normally.
(gdb)

$ ldd ./a.out
        libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x0000003d36200000)
        libm.so.6 => /lib64/libm.so.6 (0x0000003d31600000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x0000003d34e00000)
        libc.so.6 => /lib64/libc.so.6 (0x0000003d30e00000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003d2fe00000)

The library that you see as linux-vdso.so.1 is a virtual library or Virtual Dynamic Shared
Object, that resides only in each program's address space. Older systems called this 
linux-gate.so.1. This virtual library provides the necessary logic to allow user programs 
to access system functions through the fastest means available on the particular 
processor, either interrupt, or with most newer processors, fast system call.