static unsigned char __syscall_data[] = { // mov rax, [rsp+24] 0x48, 0x8b, 0x84, 0x24, 24, 0, 0, 0, // mov rdi, rax 0x48, 0x89, 0xc7, // mov rax, [rsp+32] 0x48, 0x8b, 0x84, 0x24, 32, 0, 0, 0, // mov rsi, rax 0x48, 0x89, 0xc6, // mov rax, [rsp+40] 0x48, 0x8b, 0x84, 0x24, 40, 0, 0, 0, // mov rdx, rax 0x48, 0x89, 0xc2, // mov rax, [rsp+48] 0x48, 0x8b, 0x84, 0x24, 48, 0, 0, 0, // mov r10, rax 0x49, 0x89, 0xc2, // mov rax, [rsp+56] 0x48, 0x8b, 0x84, 0x24, 56, 0, 0, 0, // mov r8, rax 0x49, 0x89, 0xc0, // mov rax, [rsp+64] 0x48, 0x8b, 0x84, 0x24, 64, 0, 0, 0, // mov r9, rax 0x49, 0x89, 0xc1, // mov rax, [rsp+16] 0x48, 0x8b, 0x84, 0x24, 16, 0, 0, 0, // syscall 0x0f, 0x05, // mov [rsp+8], rax 0x48, 0x89, 0x84, 0x24, 8, 0, 0, 0, // ret 0xc3 }; #define __syscall(no, arg1, arg2, arg3, arg4, arg5, arg6)\ (((unsigned long (*)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long))__syscall_data)\ (no, arg1, arg2, arg3, arg4, arg5, arg6)) typedef unsigned long size_t; long write(int fd, void *buf, size_t count) { __syscall(1, fd, buf, count, 0, 0, 0); } int main(int argc, char **argv) { write(1, "Hello, world!\n", 14); return 0; }