// This is an example of turning simple C into raw shellcode.

// make shellcode.bin will compile to assembly
// make shellcode.bin.pkt will prepend the length so you can
//    ./know_your_mem < shellcode.bin.pkt

// Note: Right now the 'build' does not support .(ro)data
//       If you want them you'll have to adjust the Makefile.
//       They're not really necessary to solve this challenge though.


// From https://chromium.googlesource.com/linux-syscall-support/
static int my_errno = 0;
#define SYS_ERRNO my_errno
#include "linux-syscall-support/linux_syscall_support.h"


#define ADDR_MIN   0x0000100000000000UL
#define ADDR_MASK  0x00000ffffffff000UL


void _start()
{
    sys_write(1, __builtin_frame_address(0), 5);  // Prints something (note: best avoid literals)
    sys_exit_group(2);                            // Exit
}