bot               120 kern/vm/copyinout.c 	vaddr_t bot, top;
bot               124 kern/vm/copyinout.c 	bot = (vaddr_t) userptr;
bot               125 kern/vm/copyinout.c 	top = bot+len-1;
bot               127 kern/vm/copyinout.c 	if (top < bot) {
bot               132 kern/vm/copyinout.c 	if (bot >= USERSPACETOP) {
bot               139 kern/vm/copyinout.c 		*stoplen = USERSPACETOP - bot;