Implement page fault for lazy loading executables, w/ G

tests/devices/src/lib/user/debug.c

@@ -0,0 +1,25 @@
+#include <debug.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <syscall.h>
+
+/* Aborts the user program, printing the source file name, line
+   number, and function name, plus a user-specific message. */
+void
+debug_panic (const char *file, int line, const char *function,
+             const char *message, ...)
+{
+  va_list args;
+
+  printf ("User process ABORT at %s:%d in %s(): ", file, line, function);
+
+  va_start (args, message);
+  vprintf (message, args);
+  printf ("\n");
+  va_end (args);
+
+  debug_backtrace ();
+  
+  exit (1);
+}