| 1 | /*␊ |
| 2 | * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat.␊ |
| 3 | * All rights reserved.␊ |
| 4 | *␊ |
| 5 | * Redistribution and use in source and binary forms, with or without␊ |
| 6 | * modification, are permitted provided that the following conditions␊ |
| 7 | * are met:␊ |
| 8 | * 1. Redistributions of source code must retain the above copyright␊ |
| 9 | * notice, this list of conditions and the following disclaimer.␊ |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright␊ |
| 11 | * notice, this list of conditions and the following disclaimer in the␊ |
| 12 | * documentation and/or other materials provided with the distribution.␊ |
| 13 | *␊ |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR␊ |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED␊ |
| 16 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE␊ |
| 17 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT,␊ |
| 18 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES␊ |
| 19 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR␊ |
| 20 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)␊ |
| 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,␊ |
| 22 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN␊ |
| 23 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE␊ |
| 24 | * POSSIBILITY OF SUCH DAMAGE.␊ |
| 25 | *␊ |
| 26 | */␊ |
| 27 | #include <stdio.h>␊ |
| 28 | #include <stdlib.h>␊ |
| 29 | ␊ |
| 30 | #include <sys/types.h>␊ |
| 31 | #include <sys/cdefs.h>␊ |
| 32 | #include <Availability.h>␊ |
| 33 | ␊ |
| 34 | #include <_types.h>␊ |
| 35 | extern void arc4random_buf(void *_buf, size_t n);␊ |
| 36 | extern void stop(const char *format, ...);␊ |
| 37 | extern void halt(void);␊ |
| 38 | ␊ |
| 39 | #define __arraycount(__x) (sizeof(__x) / sizeof(__x[0]))␊ |
| 40 | ␊ |
| 41 | long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};␊ |
| 42 | ␊ |
| 43 | //__private_extern__ void __guard_setup(void) /*__attribute__ ((visibility ("hidden")))*/;␊ |
| 44 | void __guard_setup(void) __attribute__((constructor));␊ |
| 45 | ␊ |
| 46 | void __stack_chk_fail(void);␊ |
| 47 | ␊ |
| 48 | ␊ |
| 49 | void␊ |
| 50 | __guard_setup(void)␊ |
| 51 | {␊ |
| 52 | ␉if (__stack_chk_guard[0]!=0) return;␊ |
| 53 | ␉␊ |
| 54 | ␉size_t i;␊ |
| 55 | ␉long guard[__arraycount(__stack_chk_guard)];␉␊ |
| 56 | ␉␊ |
| 57 | ␉arc4random_buf(guard, sizeof(guard));␊ |
| 58 | ␉for (i = 0; i < __arraycount(guard); i++)␊ |
| 59 | ␉␉__stack_chk_guard[i] = guard[i];␊ |
| 60 | ␉␊ |
| 61 | ␉if (__stack_chk_guard[0]!=0 && *__stack_chk_guard != 0) return;␊ |
| 62 | ␉␊ |
| 63 | ␉/* If a random generator can't be used, the protector switches the guard␊ |
| 64 | to the "terminator canary" */␊ |
| 65 | ␉((char*)__stack_chk_guard)[0] = 0; ((char*)__stack_chk_guard)[1] = 0;␊ |
| 66 | ␉((char*)__stack_chk_guard)[2] = '\n'; ((char*)__stack_chk_guard)[3] = 255;␉␊ |
| 67 | ␉␊ |
| 68 | }␊ |
| 69 | ␊ |
| 70 | void␊ |
| 71 | __stack_chk_fail()␊ |
| 72 | {␊ |
| 73 | #ifndef BOOT1␊ |
| 74 | ␉printf("stack overflow");␊ |
| 75 | #endif␊ |
| 76 | ␉halt();␊ |
| 77 | }␊ |
| 78 | |
