1#include <sys/cdefs.h>
2__FBSDID("$FreeBSD$");
3
4#include <sys/types.h>
5#include <sys/param.h>
6#include <sys/kernel.h>
7#include <sys/systm.h>
8#include <sys/libkern.h>
9
10long __stack_chk_guard[8] = {};
11void __stack_chk_fail(void);
12
13void
14__stack_chk_fail(void)
15{
16
17	panic("stack overflow detected; backtrace may be corrupted");
18}
19
20#define __arraycount(__x)	(sizeof(__x) / sizeof(__x[0]))
21static void
22__stack_chk_init(void *dummy __unused)
23{
24	size_t i;
25	long guard[__arraycount(__stack_chk_guard)];
26
27	arc4rand(guard, sizeof(guard), 0);
28	for (i = 0; i < __arraycount(guard); i++)
29		__stack_chk_guard[i] = guard[i];
30}
31SYSINIT(stack_chk, SI_SUB_RANDOM, SI_ORDER_ANY, __stack_chk_init, NULL);
32