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 10 long __stack_chk_guard[8] = {}; 11 void __stack_chk_fail(void); 12 13 void 14 __stack_chk_fail(void) 15 { 16 17 panic("stack overflow detected; backtrace may be corrupted"); 18 } 19 20 static void 21 __stack_chk_init(void *dummy __unused) 22 { 23 size_t i; 24 long guard[nitems(__stack_chk_guard)]; 25 26 arc4rand(guard, sizeof(guard), 0); 27 for (i = 0; i < nitems(guard); i++) 28 __stack_chk_guard[i] = guard[i]; 29 } 30 SYSINIT(stack_chk, SI_SUB_RANDOM, SI_ORDER_ANY, __stack_chk_init, NULL); 31