1 /* $NetBSD: ssp.h,v 1.13 2015/09/03 20:43:47 plunky Exp $ */ 2 3 /*- 4 * 5 * SPDX-License-Identifier: BSD-2-Clause 6 * 7 * Copyright (c) 2006, 2011 The NetBSD Foundation, Inc. 8 * All rights reserved. 9 * 10 * This code is derived from software contributed to The NetBSD Foundation 11 * by Christos Zoulas. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 #ifndef _SSP_SSP_H_ 35 #define _SSP_SSP_H_ 36 37 #include <sys/cdefs.h> 38 39 #if !defined(__cplusplus) 40 # if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && \ 41 (__OPTIMIZE__ > 0 || defined(__clang__)) 42 # if _FORTIFY_SOURCE > 1 43 # define __SSP_FORTIFY_LEVEL 2 44 # else 45 # define __SSP_FORTIFY_LEVEL 1 46 # endif 47 # else 48 # define __SSP_FORTIFY_LEVEL 0 49 # endif 50 #else 51 # define __SSP_FORTIFY_LEVEL 0 52 #endif 53 54 #define __ssp_var(type) __CONCAT(__ssp_ ## type, __COUNTER__) 55 56 /* __ssp_real is used by the implementation in libc */ 57 #if __SSP_FORTIFY_LEVEL == 0 58 #define __ssp_real_(fun) fun 59 #else 60 #define __ssp_real_(fun) __ssp_real_ ## fun 61 #endif 62 #define __ssp_real(fun) __ssp_real_(fun) 63 64 #define __ssp_inline static __inline __attribute__((__always_inline__)) 65 66 #define __ssp_bos(ptr) __builtin_object_size(ptr, __SSP_FORTIFY_LEVEL > 1) 67 #define __ssp_bos0(ptr) __builtin_object_size(ptr, 0) 68 69 #define __ssp_check(buf, len, bos) \ 70 if (bos(buf) != (size_t)-1 && (size_t)len > bos(buf)) \ 71 __chk_fail() 72 73 #define __ssp_redirect_raw_impl(rtype, fun, symbol, args) \ 74 rtype __ssp_real_(fun) args __RENAME(symbol); \ 75 __ssp_inline rtype fun args __RENAME(__ssp_protected_ ## fun); \ 76 __ssp_inline rtype fun args 77 78 #define __ssp_redirect_raw(rtype, fun, symbol, args, call, cond, bos, len) \ 79 __ssp_redirect_raw_impl(rtype, fun, symbol, args) { \ 80 if (cond) \ 81 __ssp_check(__buf, len, bos); \ 82 return __ssp_real_(fun) call; \ 83 } 84 85 #define __ssp_redirect(rtype, fun, args, call) \ 86 __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos, __len) 87 #define __ssp_redirect0(rtype, fun, args, call) \ 88 __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos0, __len) 89 90 #include <machine/_limits.h> 91 92 __ssp_inline int 93 __ssp_overlap(const void *leftp, const void *rightp, __size_t sz) 94 { 95 __uintptr_t left = (__uintptr_t)leftp; 96 __uintptr_t right = (__uintptr_t)rightp; 97 98 if (left <= right) 99 return (__SIZE_T_MAX - sz < left || right < left + sz); 100 101 return (__SIZE_T_MAX - sz < right || left < right + sz); 102 } 103 104 #include <sys/_iovec.h> 105 106 __BEGIN_DECLS 107 void __stack_chk_fail(void) __dead2; 108 void __chk_fail(void) __dead2; 109 __END_DECLS 110 111 __ssp_inline void 112 __ssp_check_iovec(const struct iovec *iov, int iovcnt) 113 { 114 const size_t iovsz = __ssp_bos(iov); 115 int i; 116 117 if (iovsz != (size_t)-1 && iovsz / sizeof(*iov) < (size_t)iovcnt) 118 __chk_fail(); 119 120 for (i = 0; i < iovcnt; i++) { 121 if (__ssp_bos(iov[i].iov_base) < iov[i].iov_len) 122 __chk_fail(); 123 } 124 } 125 126 #endif /* _SSP_SSP_H_ */ 127