include/ssp/ssp.h

   1 /*      $NetBSD: ssp.h,v 1.13 2015/09/03 20:43:47 plunky Exp $  */
   2
   3 /*-
   4  * Copyright (c) 2006, 2011 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Christos Zoulas.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 #ifndef _SSP_SSP_H_
  32 #define _SSP_SSP_H_
  33
  34 #include <sys/cdefs.h>
  35
  36 #if !defined(__cplusplus)
  37 # if _FORTIFY_SOURCE > 0 && !defined(__lint__) && \
  38      (__OPTIMIZE__ > 0 || defined(__clang__)) && __GNUC_PREREQ__(4, 1)
  39 #  if _FORTIFY_SOURCE > 1
  40 #   define __SSP_FORTIFY_LEVEL 2
  41 #  else
  42 #   define __SSP_FORTIFY_LEVEL 1
  43 #  endif
  44 # else
  45 #  define __SSP_FORTIFY_LEVEL 0
  46 # endif
  47 #else
  48 # define __SSP_FORTIFY_LEVEL 0
  49 #endif
  50
  51 /* __ssp_real is used by the implementation in libc */
  52 #if __SSP_FORTIFY_LEVEL == 0
  53 #define __ssp_real_(fun)        fun
  54 #else
  55 #define __ssp_real_(fun)        __ssp_real_ ## fun
  56 #endif
  57 #define __ssp_real(fun)         __ssp_real_(fun)
  58
  59 #define __ssp_inline static __inline __attribute__((__always_inline__))
  60
  61 #define __ssp_bos(ptr) __builtin_object_size(ptr, __SSP_FORTIFY_LEVEL > 1)
  62 #define __ssp_bos0(ptr) __builtin_object_size(ptr, 0)
  63
  64 #define __ssp_check(buf, len, bos) \
  65         if (bos(buf) != (size_t)-1 && len > bos(buf)) \
  66                 __chk_fail()
  67 #define __ssp_redirect_raw(rtype, fun, symbol, args, call, cond, bos) \
  68 rtype __ssp_real_(fun) args __RENAME(symbol); \
  69 __ssp_inline rtype fun args __RENAME(__ssp_protected_ ## fun); \
  70 __ssp_inline rtype fun args { \
  71         if (cond) \
  72                 __ssp_check(__buf, __len, bos); \
  73         return __ssp_real_(fun) call; \
  74 }
  75
  76 #define __ssp_redirect(rtype, fun, args, call) \
  77     __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos)
  78 #define __ssp_redirect0(rtype, fun, args, call) \
  79     __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos0)
  80
  81 #define __ssp_overlap(a, b, l) \
  82     (((a) <= (b) && (b) < (a) + (l)) || ((b) <= (a) && (a) < (b) + (l)))
  83
  84 __BEGIN_DECLS
  85 void __stack_chk_fail(void) __dead;
  86 void __chk_fail(void) __dead;
  87 __END_DECLS
  88
  89 #endif /* _SSP_SSP_H_ */