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