start moving malloc and friends in

userland/c/malloc.c

@@ -0,0 +1,22 @@
+/* https://cirosantilli.com/linux-kernel-module-cheat#malloc */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    size_t bytes = sizeof(int) * 2;
+    /* Allocate 2 ints. */
+    int *is = malloc(bytes);
+    /* This can happen for example if we ask for too much memory. */
+    if (is == NULL) {
+        perror("malloc");
+        exit(EXIT_FAILURE);
+    }
+    is[0] = 1;
+    assert(is[0] == 1);
+    /* Free the allocated memory. */
+    free(is);
+    return EXIT_SUCCESS;
+}
+