1180012Sru#include <sys/cdefs.h>
2180012Sru__FBSDID("$FreeBSD$");
3180012Sru
4180012Sru#include <sys/types.h>
5180012Sru#include <sys/param.h>
6180012Sru#include <sys/kernel.h>
7180012Sru#include <sys/systm.h>
8180012Sru#include <sys/libkern.h>
9180012Sru
10180012Srulong __stack_chk_guard[8] = {};
11180012Sruvoid __stack_chk_fail(void);
12180012Sru
13180012Sruvoid
14180012Sru__stack_chk_fail(void)
15180012Sru{
16180012Sru
17180012Sru	panic("stack overflow detected; backtrace may be corrupted");
18180012Sru}
19180012Sru
20180012Srustatic void
21180012Sru__stack_chk_init(void *dummy __unused)
22180012Sru{
23180012Sru	size_t i;
24284462Spfg	long guard[nitems(__stack_chk_guard)];
25180012Sru
26180012Sru	arc4rand(guard, sizeof(guard), 0);
27284462Spfg	for (i = 0; i < nitems(guard); i++)
28180012Sru		__stack_chk_guard[i] = guard[i];
29180012Sru}
30198295SruSYSINIT(stack_chk, SI_SUB_RANDOM, SI_ORDER_ANY, __stack_chk_init, NULL);
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