stack_protector.c revision 198295
1229159Sadrian#include <sys/cdefs.h> 2229159Sadrian__FBSDID("$FreeBSD: head/sys/kern/stack_protector.c 198295 2009-10-20 16:36:51Z ru $"); 3229159Sadrian 4229159Sadrian#include <sys/types.h> 5229159Sadrian#include <sys/param.h> 6229159Sadrian#include <sys/kernel.h> 7229159Sadrian#include <sys/systm.h> 8229159Sadrian#include <sys/libkern.h> 9229159Sadrian 10229159Sadrianlong __stack_chk_guard[8] = {}; 11229159Sadrianvoid __stack_chk_fail(void); 12229159Sadrian 13229159Sadrianvoid 14229159Sadrian__stack_chk_fail(void) 15229159Sadrian{ 16229159Sadrian 17229159Sadrian panic("stack overflow detected; backtrace may be corrupted"); 18229159Sadrian} 19229159Sadrian 20229159Sadrian#define __arraycount(__x) (sizeof(__x) / sizeof(__x[0])) 21229159Sadrianstatic void 22229159Sadrian__stack_chk_init(void *dummy __unused) 23229159Sadrian{ 24229159Sadrian size_t i; 25229159Sadrian long guard[__arraycount(__stack_chk_guard)]; 26229159Sadrian 27229159Sadrian arc4rand(guard, sizeof(guard), 0); 28229159Sadrian for (i = 0; i < __arraycount(guard); i++) 29229159Sadrian __stack_chk_guard[i] = guard[i]; 30229159Sadrian} 31229159SadrianSYSINIT(stack_chk, SI_SUB_RANDOM, SI_ORDER_ANY, __stack_chk_init, NULL); 32229159Sadrian