gcc/asan.h

   1 /* AddressSanitizer, a fast memory error detector.
   2    Copyright (C) 2011-2013 Free Software Foundation, Inc.
   3    Contributed by Kostya Serebryany <kcc@google.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef TREE_ASAN
  22 #define TREE_ASAN
  23
  24 extern void asan_function_start (void);
  25 extern void asan_finish_file (void);
  26 extern rtx asan_emit_stack_protection (rtx, HOST_WIDE_INT *, tree *, int);
  27 extern bool asan_protect_global (tree);
  28 extern void initialize_sanitizer_builtins (void);
  29
  30 /* Alias set for accessing the shadow memory.  */
  31 extern alias_set_type asan_shadow_set;
  32
  33 /* Shadow memory is found at
  34    (address >> ASAN_SHADOW_SHIFT) + targetm.asan_shadow_offset ().  */
  35 #define ASAN_SHADOW_SHIFT       3
  36
  37 /* Red zone size, stack and global variables are padded by ASAN_RED_ZONE_SIZE
  38    up to 2 * ASAN_RED_ZONE_SIZE - 1 bytes.  */
  39 #define ASAN_RED_ZONE_SIZE      32
  40
  41 /* Shadow memory values for stack protection.  Left is below protected vars,
  42    the first pointer in stack corresponding to that offset contains
  43    ASAN_STACK_FRAME_MAGIC word, the second pointer to a string describing
  44    the frame.  Middle is for padding in between variables, right is
  45    above the last protected variable and partial immediately after variables
  46    up to ASAN_RED_ZONE_SIZE alignment.  */
  47 #define ASAN_STACK_MAGIC_LEFT           0xf1
  48 #define ASAN_STACK_MAGIC_MIDDLE         0xf2
  49 #define ASAN_STACK_MAGIC_RIGHT          0xf3
  50 #define ASAN_STACK_MAGIC_PARTIAL        0xf4
  51
  52 #define ASAN_STACK_FRAME_MAGIC  0x41b58ab3
  53
  54 /* Return true if DECL should be guarded on the stack.  */
  55
  56 static inline bool
  57 asan_protect_stack_decl (tree decl)
  58 {
  59   return DECL_P (decl) && !DECL_ARTIFICIAL (decl);
  60 }
  61
  62 /* Return the size of padding needed to insert after a protected
  63    decl of SIZE.  */
  64
  65 static inline unsigned int
  66 asan_red_zone_size (unsigned int size)
  67 {
  68   unsigned int c = size & (ASAN_RED_ZONE_SIZE - 1);
  69   return c ? 2 * ASAN_RED_ZONE_SIZE - c : ASAN_RED_ZONE_SIZE;
  70 }
  71
  72 #endif /* TREE_ASAN */