$ gcc -g -O0 -nostdlib main.c ident.S
$ valgrind ./a.out 
==17819== Memcheck, a memory error detector
==17819== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==17819== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==17819== Command: ./a.out
==17819== 
==17819== 
==17819== HEAP SUMMARY:
==17819==     in use at exit: 0 bytes in 0 blocks
==17819==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==17819== 
==17819== All heap blocks were freed -- no leaks are possible
==17819== 
==17819== For counts of detected and suppressed errors, rerun with: -v
==17819== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
$ cat main.c ident.S
int
_start(int argc, char **argv)
{
	int a[10];

//	a[argc + 20] = 0; // toast
//	a[argc + 21] = 0; // toast

	__asm__ __volatile__(
		"movq $1, %rax\n" // SYS_exit
		"syscall\n");
}
.section ".note.netbsd.ident", "a", @note
.long 2f-1f
.long 4f-3f
.long 1
1: .asciz "NetBSD"
2: .p2align 2
3: .long 700000001
4: .p2align 2