gcc/asan.h

   1 /* AddressSanitizer, a fast memory error detector.
   2    Copyright (C) 2011, 2012 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_finish_file (void);
  25 extern rtx asan_emit_stack_protection (rtx, HOST_WIDE_INT *, tree *, int);
  26 extern bool asan_protect_global (tree);
  27
  28 /* Alias set for accessing the shadow memory.  */
  29 extern alias_set_type asan_shadow_set;
  30
  31 /* Shadow memory is found at
  32    (address >> ASAN_SHADOW_SHIFT) + targetm.asan_shadow_offset ().  */
  33 #define ASAN_SHADOW_SHIFT       3
  34
  35 /* Red zone size, stack and global variables are padded by ASAN_RED_ZONE_SIZE
  36    up to 2 * ASAN_RED_ZONE_SIZE - 1 bytes.  */
  37 #define ASAN_RED_ZONE_SIZE      32
  38
  39 /* Shadow memory values for stack protection.  Left is below protected vars,
  40    the first pointer in stack corresponding to that offset contains
  41    ASAN_STACK_FRAME_MAGIC word, the second pointer to a string describing
  42    the frame.  Middle is for padding in between variables, right is
  43    above the last protected variable and partial immediately after variables
  44    up to ASAN_RED_ZONE_SIZE alignment.  */
  45 #define ASAN_STACK_MAGIC_LEFT           0xf1
  46 #define ASAN_STACK_MAGIC_MIDDLE         0xf2
  47 #define ASAN_STACK_MAGIC_RIGHT          0xf3
  48 #define ASAN_STACK_MAGIC_PARTIAL        0xf4
  49
  50 #define ASAN_STACK_FRAME_MAGIC  0x41b58ab3
  51
  52 /* Return true if DECL should be guarded on the stack.  */
  53
  54 static inline bool
  55 asan_protect_stack_decl (tree decl)
  56 {
  57   return DECL_P (decl) && !DECL_ARTIFICIAL (decl);
  58 }
  59
  60 /* Return the size of padding needed to insert after a protected
  61    decl of SIZE.  */
  62
  63 static inline unsigned int
  64 asan_red_zone_size (unsigned int size)
  65 {
  66   unsigned int c = size & (ASAN_RED_ZONE_SIZE - 1);
  67   return c ? 2 * ASAN_RED_ZONE_SIZE - c : ASAN_RED_ZONE_SIZE;
  68 }
  69
  70 #endif /* TREE_ASAN */