1 | /*
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2 | * Tiny C Memory and bounds checker
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3 | *
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4 | * Copyright (c) 2002 Fabrice Bellard
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5 | *
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6 | * This library is free software; you can redistribute it and/or
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7 | * modify it under the terms of the GNU Lesser General Public
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8 | * License as published by the Free Software Foundation; either
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9 | * version 2 of the License, or (at your option) any later version.
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10 | *
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11 | * This library is distributed in the hope that it will be useful,
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | * Lesser General Public License for more details.
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15 | *
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16 | * You should have received a copy of the GNU Lesser General Public
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17 | * License along with this library; if not, write to the Free Software
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18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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19 | */
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20 | #include <stdlib.h>
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21 | #include <stdio.h>
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22 | #include <stdarg.h>
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23 | #include <string.h>
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24 |
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25 | #if !defined(__FreeBSD__) \
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26 | && !defined(__FreeBSD_kernel__) \
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27 | && !defined(__DragonFly__) \
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28 | && !defined(__OpenBSD__) \
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29 | && !defined(__NetBSD__)
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30 | #include <malloc.h>
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31 | #endif
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32 |
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33 | #if !defined(_WIN32)
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34 | #include <unistd.h>
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35 | #endif
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36 |
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37 | /* #define BOUND_DEBUG */
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38 |
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39 | #ifdef BOUND_DEBUG
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40 | #define dprintf(a...) fprintf(a)
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41 | #else
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42 | #define dprintf(a...)
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43 | #endif
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44 |
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45 | /* define so that bound array is static (faster, but use memory if
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46 | bound checking not used) */
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47 | /* #define BOUND_STATIC */
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48 |
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49 | /* use malloc hooks. Currently the code cannot be reliable if no hooks */
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50 | #define CONFIG_TCC_MALLOC_HOOKS
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51 | #define HAVE_MEMALIGN
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52 |
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53 | #if defined(__FreeBSD__) \
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54 | || defined(__FreeBSD_kernel__) \
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55 | || defined(__DragonFly__) \
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56 | || defined(__OpenBSD__) \
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57 | || defined(__NetBSD__) \
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58 | || defined(__dietlibc__) \
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59 | || defined(_WIN32)
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60 | //#warning Bound checking does not support malloc (etc.) in this environment.
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61 | #undef CONFIG_TCC_MALLOC_HOOKS
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62 | #undef HAVE_MEMALIGN
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63 | #endif
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64 |
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65 | #define BOUND_T1_BITS 13
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66 | #define BOUND_T2_BITS 11
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67 | #define BOUND_T3_BITS (sizeof(size_t)*8 - BOUND_T1_BITS - BOUND_T2_BITS)
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68 | #define BOUND_E_BITS (sizeof(size_t))
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69 |
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70 | #define BOUND_T1_SIZE ((size_t)1 << BOUND_T1_BITS)
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71 | #define BOUND_T2_SIZE ((size_t)1 << BOUND_T2_BITS)
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72 | #define BOUND_T3_SIZE ((size_t)1 << BOUND_T3_BITS)
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73 |
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74 | #define BOUND_T23_BITS (BOUND_T2_BITS + BOUND_T3_BITS)
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75 | #define BOUND_T23_SIZE ((size_t)1 << BOUND_T23_BITS)
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76 |
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77 |
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78 | /* this pointer is generated when bound check is incorrect */
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79 | #define INVALID_POINTER ((void *)(-2))
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80 | /* size of an empty region */
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81 | #define EMPTY_SIZE ((size_t)(-1))
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82 | /* size of an invalid region */
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83 | #define INVALID_SIZE 0
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84 |
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85 | typedef struct BoundEntry {
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86 | size_t start;
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87 | size_t size;
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88 | struct BoundEntry *next;
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89 | size_t is_invalid; /* true if pointers outside region are invalid */
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90 | } BoundEntry;
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91 |
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92 | /* external interface */
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93 | void __bound_init(void);
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94 | void __bound_new_region(void *p, size_t size);
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95 | int __bound_delete_region(void *p);
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96 |
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97 | #ifdef __attribute__
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98 | /* an __attribute__ macro is defined in the system headers */
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99 | #undef __attribute__
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100 | #endif
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101 | #define FASTCALL __attribute__((regparm(3)))
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102 |
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103 | void *__bound_malloc(size_t size, const void *caller);
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104 | void *__bound_memalign(size_t size, size_t align, const void *caller);
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105 | void __bound_free(void *ptr, const void *caller);
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106 | void *__bound_realloc(void *ptr, size_t size, const void *caller);
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107 | static void *libc_malloc(size_t size);
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108 | static void libc_free(void *ptr);
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109 | static void install_malloc_hooks(void);
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110 | static void restore_malloc_hooks(void);
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111 |
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112 | #ifdef CONFIG_TCC_MALLOC_HOOKS
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113 | static void *saved_malloc_hook;
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114 | static void *saved_free_hook;
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115 | static void *saved_realloc_hook;
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116 | static void *saved_memalign_hook;
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117 | #endif
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118 |
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119 | /* TCC definitions */
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120 | extern char __bounds_start; /* start of static bounds table */
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121 | /* error message, just for TCC */
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122 | const char *__bound_error_msg;
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123 |
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124 | /* runtime error output */
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125 | extern void rt_error(size_t pc, const char *fmt, ...);
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126 |
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127 | #ifdef BOUND_STATIC
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128 | static BoundEntry *__bound_t1[BOUND_T1_SIZE]; /* page table */
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129 | #else
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130 | static BoundEntry **__bound_t1; /* page table */
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131 | #endif
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132 | static BoundEntry *__bound_empty_t2; /* empty page, for unused pages */
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133 | static BoundEntry *__bound_invalid_t2; /* invalid page, for invalid pointers */
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134 |
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135 | static BoundEntry *__bound_find_region(BoundEntry *e1, void *p)
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136 | {
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137 | size_t addr, tmp;
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138 | BoundEntry *e;
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139 |
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140 | e = e1;
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141 | while (e != NULL) {
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142 | addr = (size_t)p;
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143 | addr -= e->start;
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144 | if (addr <= e->size) {
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145 | /* put region at the head */
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146 | tmp = e1->start;
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147 | e1->start = e->start;
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148 | e->start = tmp;
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149 | tmp = e1->size;
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150 | e1->size = e->size;
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151 | e->size = tmp;
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152 | return e1;
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153 | }
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154 | e = e->next;
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155 | }
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156 | /* no entry found: return empty entry or invalid entry */
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157 | if (e1->is_invalid)
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158 | return __bound_invalid_t2;
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159 | else
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160 | return __bound_empty_t2;
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161 | }
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162 |
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163 | /* print a bound error message */
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164 | static void bound_error(const char *fmt, ...)
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165 | {
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166 | __bound_error_msg = fmt;
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167 | fprintf(stderr,"%s %s: %s\n", __FILE__, __FUNCTION__, fmt);
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168 | *(void **)0 = 0; /* force a runtime error */
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169 | }
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170 |
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171 | static void bound_alloc_error(void)
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172 | {
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173 | bound_error("not enough memory for bound checking code");
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174 | }
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175 |
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176 | /* return '(p + offset)' for pointer arithmetic (a pointer can reach
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177 | the end of a region in this case */
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178 | void * FASTCALL __bound_ptr_add(void *p, size_t offset)
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179 | {
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180 | size_t addr = (size_t)p;
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181 | BoundEntry *e;
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182 |
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183 | dprintf(stderr, "%s %s: %p %x\n",
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184 | __FILE__, __FUNCTION__, p, (unsigned)offset);
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185 |
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186 | __bound_init();
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187 |
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188 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
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189 | e = (BoundEntry *)((char *)e +
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190 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &
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191 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
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192 | addr -= e->start;
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193 | if (addr > e->size) {
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194 | e = __bound_find_region(e, p);
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195 | addr = (size_t)p - e->start;
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196 | }
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197 | addr += offset;
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198 | if (addr >= e->size) {
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199 | fprintf(stderr,"%s %s: %p is outside of the region\n",
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200 | __FILE__, __FUNCTION__, p + offset);
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201 | return INVALID_POINTER; /* return an invalid pointer */
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202 | }
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203 | return p + offset;
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204 | }
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205 |
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206 | /* return '(p + offset)' for pointer indirection (the resulting must
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207 | be strictly inside the region */
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208 | #define BOUND_PTR_INDIR(dsize) \
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209 | void * FASTCALL __bound_ptr_indir ## dsize (void *p, size_t offset) \
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210 | { \
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211 | size_t addr = (size_t)p; \
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212 | BoundEntry *e; \
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213 | \
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214 | dprintf(stderr, "%s %s: %p %x start\n", \
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215 | __FILE__, __FUNCTION__, p, (unsigned)offset); \
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216 | \
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217 | __bound_init(); \
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218 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)]; \
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219 | e = (BoundEntry *)((char *)e + \
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220 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & \
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221 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS))); \
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222 | addr -= e->start; \
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223 | if (addr > e->size) { \
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224 | e = __bound_find_region(e, p); \
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225 | addr = (size_t)p - e->start; \
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226 | } \
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227 | addr += offset + dsize; \
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228 | if (addr > e->size) { \
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229 | fprintf(stderr,"%s %s: %p is outside of the region\n", \
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230 | __FILE__, __FUNCTION__, p + offset); \
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231 | return INVALID_POINTER; /* return an invalid pointer */ \
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232 | } \
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233 | dprintf(stderr, "%s %s: return p+offset = %p\n", \
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234 | __FILE__, __FUNCTION__, p + offset); \
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235 | return p + offset; \
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236 | }
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237 |
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238 | BOUND_PTR_INDIR(1)
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239 | BOUND_PTR_INDIR(2)
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240 | BOUND_PTR_INDIR(4)
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241 | BOUND_PTR_INDIR(8)
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242 | BOUND_PTR_INDIR(12)
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243 | BOUND_PTR_INDIR(16)
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244 |
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245 | #if defined(__GNUC__) && (__GNUC__ >= 6)
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246 | /*
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247 | * At least gcc 6.2 complains when __builtin_frame_address is used with
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248 | * nonzero argument.
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249 | */
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250 | #pragma GCC diagnostic push
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251 | #pragma GCC diagnostic ignored "-Wframe-address"
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252 | #endif
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253 |
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254 | /* return the frame pointer of the caller */
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255 | #define GET_CALLER_FP(fp)\
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256 | {\
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257 | fp = (size_t)__builtin_frame_address(1);\
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258 | }
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259 |
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260 | /* called when entering a function to add all the local regions */
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261 | void FASTCALL __bound_local_new(void *p1)
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262 | {
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263 | size_t addr, size, fp, *p = p1;
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264 |
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265 | dprintf(stderr, "%s, %s start p1=%p\n", __FILE__, __FUNCTION__, p);
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266 | GET_CALLER_FP(fp);
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267 | for(;;) {
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268 | addr = p[0];
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269 | if (addr == 0)
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270 | break;
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271 | addr += fp;
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272 | size = p[1];
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273 | p += 2;
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274 | __bound_new_region((void *)addr, size);
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275 | }
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276 | dprintf(stderr, "%s, %s end\n", __FILE__, __FUNCTION__);
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277 | }
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278 |
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279 | /* called when leaving a function to delete all the local regions */
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280 | void FASTCALL __bound_local_delete(void *p1)
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281 | {
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282 | size_t addr, fp, *p = p1;
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283 | GET_CALLER_FP(fp);
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284 | for(;;) {
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285 | addr = p[0];
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286 | if (addr == 0)
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287 | break;
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288 | addr += fp;
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289 | p += 2;
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290 | __bound_delete_region((void *)addr);
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291 | }
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292 | }
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293 |
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294 | #if defined(__GNUC__) && (__GNUC__ >= 6)
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295 | #pragma GCC diagnostic pop
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296 | #endif
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297 |
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298 | static BoundEntry *__bound_new_page(void)
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299 | {
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300 | BoundEntry *page;
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301 | size_t i;
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302 |
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303 | page = libc_malloc(sizeof(BoundEntry) * BOUND_T2_SIZE);
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304 | if (!page)
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305 | bound_alloc_error();
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306 | for(i=0;i<BOUND_T2_SIZE;i++) {
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307 | /* put empty entries */
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308 | page[i].start = 0;
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309 | page[i].size = EMPTY_SIZE;
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310 | page[i].next = NULL;
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311 | page[i].is_invalid = 0;
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312 | }
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313 | return page;
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314 | }
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315 |
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316 | /* currently we use malloc(). Should use bound_new_page() */
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317 | static BoundEntry *bound_new_entry(void)
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318 | {
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319 | BoundEntry *e;
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320 | e = libc_malloc(sizeof(BoundEntry));
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321 | return e;
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322 | }
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323 |
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324 | static void bound_free_entry(BoundEntry *e)
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325 | {
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326 | libc_free(e);
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327 | }
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328 |
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329 | static BoundEntry *get_page(size_t index)
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330 | {
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331 | BoundEntry *page;
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332 | page = __bound_t1[index];
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333 | if (!page || page == __bound_empty_t2 || page == __bound_invalid_t2) {
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334 | /* create a new page if necessary */
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335 | page = __bound_new_page();
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336 | __bound_t1[index] = page;
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337 | }
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338 | return page;
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339 | }
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340 |
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341 | /* mark a region as being invalid (can only be used during init) */
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342 | static void mark_invalid(size_t addr, size_t size)
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343 | {
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344 | size_t start, end;
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345 | BoundEntry *page;
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346 | size_t t1_start, t1_end, i, j, t2_start, t2_end;
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347 |
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348 | start = addr;
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349 | end = addr + size;
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350 |
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351 | t2_start = (start + BOUND_T3_SIZE - 1) >> BOUND_T3_BITS;
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352 | if (end != 0)
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353 | t2_end = end >> BOUND_T3_BITS;
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354 | else
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355 | t2_end = 1 << (BOUND_T1_BITS + BOUND_T2_BITS);
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356 |
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357 | #if 0
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358 | dprintf(stderr, "mark_invalid: start = %x %x\n", t2_start, t2_end);
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359 | #endif
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360 |
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361 | /* first we handle full pages */
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362 | t1_start = (t2_start + BOUND_T2_SIZE - 1) >> BOUND_T2_BITS;
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363 | t1_end = t2_end >> BOUND_T2_BITS;
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364 |
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365 | i = t2_start & (BOUND_T2_SIZE - 1);
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366 | j = t2_end & (BOUND_T2_SIZE - 1);
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367 |
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368 | if (t1_start == t1_end) {
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369 | page = get_page(t2_start >> BOUND_T2_BITS);
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370 | for(; i < j; i++) {
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371 | page[i].size = INVALID_SIZE;
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372 | page[i].is_invalid = 1;
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373 | }
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374 | } else {
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375 | if (i > 0) {
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376 | page = get_page(t2_start >> BOUND_T2_BITS);
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377 | for(; i < BOUND_T2_SIZE; i++) {
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378 | page[i].size = INVALID_SIZE;
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379 | page[i].is_invalid = 1;
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380 | }
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381 | }
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382 | for(i = t1_start; i < t1_end; i++) {
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383 | __bound_t1[i] = __bound_invalid_t2;
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384 | }
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385 | if (j != 0) {
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386 | page = get_page(t1_end);
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387 | for(i = 0; i < j; i++) {
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388 | page[i].size = INVALID_SIZE;
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389 | page[i].is_invalid = 1;
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390 | }
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391 | }
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392 | }
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393 | }
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394 |
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395 | void __bound_init(void)
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396 | {
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397 | size_t i;
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398 | BoundEntry *page;
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399 | size_t start, size;
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400 | size_t *p;
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401 |
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402 | static int inited;
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403 | if (inited)
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404 | return;
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405 |
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406 | inited = 1;
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407 |
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408 | dprintf(stderr, "%s, %s() start\n", __FILE__, __FUNCTION__);
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409 |
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410 | /* save malloc hooks and install bound check hooks */
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411 | install_malloc_hooks();
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412 |
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413 | #ifndef BOUND_STATIC
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414 | __bound_t1 = libc_malloc(BOUND_T1_SIZE * sizeof(BoundEntry *));
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415 | if (!__bound_t1)
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416 | bound_alloc_error();
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417 | #endif
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418 | __bound_empty_t2 = __bound_new_page();
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419 | for(i=0;i<BOUND_T1_SIZE;i++) {
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420 | __bound_t1[i] = __bound_empty_t2;
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421 | }
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422 |
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423 | page = __bound_new_page();
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424 | for(i=0;i<BOUND_T2_SIZE;i++) {
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425 | /* put invalid entries */
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426 | page[i].start = 0;
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427 | page[i].size = INVALID_SIZE;
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428 | page[i].next = NULL;
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429 | page[i].is_invalid = 1;
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430 | }
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431 | __bound_invalid_t2 = page;
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432 |
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433 | /* invalid pointer zone */
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434 | start = (size_t)INVALID_POINTER & ~(BOUND_T23_SIZE - 1);
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435 | size = BOUND_T23_SIZE;
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436 | mark_invalid(start, size);
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437 |
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438 | #if defined(CONFIG_TCC_MALLOC_HOOKS)
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439 | /* malloc zone is also marked invalid. can only use that with
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440 | * hooks because all libs should use the same malloc. The solution
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441 | * would be to build a new malloc for tcc.
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442 | *
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443 | * usually heap (= malloc zone) comes right after bss, i.e. after _end, but
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444 | * not always - either if we are running from under `tcc -b -run`, or if
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445 | * address space randomization is turned on(a), heap start will be separated
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446 | * from bss end.
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447 | *
|
---|
448 | * So sbrk(0) will be a good approximation for start_brk:
|
---|
449 | *
|
---|
450 | * - if we are a separately compiled program, __bound_init() runs early,
|
---|
451 | * and sbrk(0) should be equal or very near to start_brk(b) (in case other
|
---|
452 | * constructors malloc something), or
|
---|
453 | *
|
---|
454 | * - if we are running from under `tcc -b -run`, sbrk(0) will return
|
---|
455 | * start of heap portion which is under this program control, and not
|
---|
456 | * mark as invalid earlier allocated memory.
|
---|
457 | *
|
---|
458 | *
|
---|
459 | * (a) /proc/sys/kernel/randomize_va_space = 2, on Linux;
|
---|
460 | * usually turned on by default.
|
---|
461 | *
|
---|
462 | * (b) on Linux >= v3.3, the alternative is to read
|
---|
463 | * start_brk from /proc/self/stat
|
---|
464 | */
|
---|
465 | start = (size_t)sbrk(0);
|
---|
466 | size = 128 * 0x100000;
|
---|
467 | mark_invalid(start, size);
|
---|
468 | #endif
|
---|
469 |
|
---|
470 | /* add all static bound check values */
|
---|
471 | p = (size_t *)&__bounds_start;
|
---|
472 | while (p[0] != 0) {
|
---|
473 | __bound_new_region((void *)p[0], p[1]);
|
---|
474 | p += 2;
|
---|
475 | }
|
---|
476 |
|
---|
477 | dprintf(stderr, "%s, %s() end\n\n", __FILE__, __FUNCTION__);
|
---|
478 | }
|
---|
479 |
|
---|
480 | void __bound_main_arg(void **p)
|
---|
481 | {
|
---|
482 | void *start = p;
|
---|
483 | while (*p++);
|
---|
484 |
|
---|
485 | dprintf(stderr, "%s, %s calling __bound_new_region(%p %x)\n",
|
---|
486 | __FILE__, __FUNCTION__, start, (unsigned)((void *)p - start));
|
---|
487 |
|
---|
488 | __bound_new_region(start, (void *) p - start);
|
---|
489 | }
|
---|
490 |
|
---|
491 | void __bound_exit(void)
|
---|
492 | {
|
---|
493 | dprintf(stderr, "%s, %s()\n", __FILE__, __FUNCTION__);
|
---|
494 | restore_malloc_hooks();
|
---|
495 | }
|
---|
496 |
|
---|
497 | static inline void add_region(BoundEntry *e,
|
---|
498 | size_t start, size_t size)
|
---|
499 | {
|
---|
500 | BoundEntry *e1;
|
---|
501 | if (e->start == 0) {
|
---|
502 | /* no region : add it */
|
---|
503 | e->start = start;
|
---|
504 | e->size = size;
|
---|
505 | } else {
|
---|
506 | /* already regions in the list: add it at the head */
|
---|
507 | e1 = bound_new_entry();
|
---|
508 | e1->start = e->start;
|
---|
509 | e1->size = e->size;
|
---|
510 | e1->next = e->next;
|
---|
511 | e->start = start;
|
---|
512 | e->size = size;
|
---|
513 | e->next = e1;
|
---|
514 | }
|
---|
515 | }
|
---|
516 |
|
---|
517 | /* create a new region. It should not already exist in the region list */
|
---|
518 | void __bound_new_region(void *p, size_t size)
|
---|
519 | {
|
---|
520 | size_t start, end;
|
---|
521 | BoundEntry *page, *e, *e2;
|
---|
522 | size_t t1_start, t1_end, i, t2_start, t2_end;
|
---|
523 |
|
---|
524 | dprintf(stderr, "%s, %s(%p, %x) start\n",
|
---|
525 | __FILE__, __FUNCTION__, p, (unsigned)size);
|
---|
526 |
|
---|
527 | __bound_init();
|
---|
528 |
|
---|
529 | start = (size_t)p;
|
---|
530 | end = start + size;
|
---|
531 | t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
532 | t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
533 |
|
---|
534 | /* start */
|
---|
535 | page = get_page(t1_start);
|
---|
536 | t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
537 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
538 | t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
539 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
540 |
|
---|
541 |
|
---|
542 | e = (BoundEntry *)((char *)page + t2_start);
|
---|
543 | add_region(e, start, size);
|
---|
544 |
|
---|
545 | if (t1_end == t1_start) {
|
---|
546 | /* same ending page */
|
---|
547 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
548 | if (e2 > e) {
|
---|
549 | e++;
|
---|
550 | for(;e<e2;e++) {
|
---|
551 | e->start = start;
|
---|
552 | e->size = size;
|
---|
553 | }
|
---|
554 | add_region(e, start, size);
|
---|
555 | }
|
---|
556 | } else {
|
---|
557 | /* mark until end of page */
|
---|
558 | e2 = page + BOUND_T2_SIZE;
|
---|
559 | e++;
|
---|
560 | for(;e<e2;e++) {
|
---|
561 | e->start = start;
|
---|
562 | e->size = size;
|
---|
563 | }
|
---|
564 | /* mark intermediate pages, if any */
|
---|
565 | for(i=t1_start+1;i<t1_end;i++) {
|
---|
566 | page = get_page(i);
|
---|
567 | e2 = page + BOUND_T2_SIZE;
|
---|
568 | for(e=page;e<e2;e++) {
|
---|
569 | e->start = start;
|
---|
570 | e->size = size;
|
---|
571 | }
|
---|
572 | }
|
---|
573 | /* last page */
|
---|
574 | page = get_page(t1_end);
|
---|
575 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
576 | for(e=page;e<e2;e++) {
|
---|
577 | e->start = start;
|
---|
578 | e->size = size;
|
---|
579 | }
|
---|
580 | add_region(e, start, size);
|
---|
581 | }
|
---|
582 |
|
---|
583 | dprintf(stderr, "%s, %s end\n", __FILE__, __FUNCTION__);
|
---|
584 | }
|
---|
585 |
|
---|
586 | /* delete a region */
|
---|
587 | static inline void delete_region(BoundEntry *e, void *p, size_t empty_size)
|
---|
588 | {
|
---|
589 | size_t addr;
|
---|
590 | BoundEntry *e1;
|
---|
591 |
|
---|
592 | addr = (size_t)p;
|
---|
593 | addr -= e->start;
|
---|
594 | if (addr <= e->size) {
|
---|
595 | /* region found is first one */
|
---|
596 | e1 = e->next;
|
---|
597 | if (e1 == NULL) {
|
---|
598 | /* no more region: mark it empty */
|
---|
599 | e->start = 0;
|
---|
600 | e->size = empty_size;
|
---|
601 | } else {
|
---|
602 | /* copy next region in head */
|
---|
603 | e->start = e1->start;
|
---|
604 | e->size = e1->size;
|
---|
605 | e->next = e1->next;
|
---|
606 | bound_free_entry(e1);
|
---|
607 | }
|
---|
608 | } else {
|
---|
609 | /* find the matching region */
|
---|
610 | for(;;) {
|
---|
611 | e1 = e;
|
---|
612 | e = e->next;
|
---|
613 | /* region not found: do nothing */
|
---|
614 | if (e == NULL)
|
---|
615 | break;
|
---|
616 | addr = (size_t)p - e->start;
|
---|
617 | if (addr <= e->size) {
|
---|
618 | /* found: remove entry */
|
---|
619 | e1->next = e->next;
|
---|
620 | bound_free_entry(e);
|
---|
621 | break;
|
---|
622 | }
|
---|
623 | }
|
---|
624 | }
|
---|
625 | }
|
---|
626 |
|
---|
627 | /* WARNING: 'p' must be the starting point of the region. */
|
---|
628 | /* return non zero if error */
|
---|
629 | int __bound_delete_region(void *p)
|
---|
630 | {
|
---|
631 | size_t start, end, addr, size, empty_size;
|
---|
632 | BoundEntry *page, *e, *e2;
|
---|
633 | size_t t1_start, t1_end, t2_start, t2_end, i;
|
---|
634 |
|
---|
635 | dprintf(stderr, "%s %s() start\n", __FILE__, __FUNCTION__);
|
---|
636 |
|
---|
637 | __bound_init();
|
---|
638 |
|
---|
639 | start = (size_t)p;
|
---|
640 | t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
641 | t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
642 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
643 |
|
---|
644 | /* find region size */
|
---|
645 | page = __bound_t1[t1_start];
|
---|
646 | e = (BoundEntry *)((char *)page + t2_start);
|
---|
647 | addr = start - e->start;
|
---|
648 | if (addr > e->size)
|
---|
649 | e = __bound_find_region(e, p);
|
---|
650 | /* test if invalid region */
|
---|
651 | if (e->size == EMPTY_SIZE || (size_t)p != e->start)
|
---|
652 | return -1;
|
---|
653 | /* compute the size we put in invalid regions */
|
---|
654 | if (e->is_invalid)
|
---|
655 | empty_size = INVALID_SIZE;
|
---|
656 | else
|
---|
657 | empty_size = EMPTY_SIZE;
|
---|
658 | size = e->size;
|
---|
659 | end = start + size;
|
---|
660 |
|
---|
661 | /* now we can free each entry */
|
---|
662 | t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
663 | t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
664 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
665 |
|
---|
666 | delete_region(e, p, empty_size);
|
---|
667 | if (t1_end == t1_start) {
|
---|
668 | /* same ending page */
|
---|
669 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
670 | if (e2 > e) {
|
---|
671 | e++;
|
---|
672 | for(;e<e2;e++) {
|
---|
673 | e->start = 0;
|
---|
674 | e->size = empty_size;
|
---|
675 | }
|
---|
676 | delete_region(e, p, empty_size);
|
---|
677 | }
|
---|
678 | } else {
|
---|
679 | /* mark until end of page */
|
---|
680 | e2 = page + BOUND_T2_SIZE;
|
---|
681 | e++;
|
---|
682 | for(;e<e2;e++) {
|
---|
683 | e->start = 0;
|
---|
684 | e->size = empty_size;
|
---|
685 | }
|
---|
686 | /* mark intermediate pages, if any */
|
---|
687 | /* XXX: should free them */
|
---|
688 | for(i=t1_start+1;i<t1_end;i++) {
|
---|
689 | page = get_page(i);
|
---|
690 | e2 = page + BOUND_T2_SIZE;
|
---|
691 | for(e=page;e<e2;e++) {
|
---|
692 | e->start = 0;
|
---|
693 | e->size = empty_size;
|
---|
694 | }
|
---|
695 | }
|
---|
696 | /* last page */
|
---|
697 | page = get_page(t1_end);
|
---|
698 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
699 | for(e=page;e<e2;e++) {
|
---|
700 | e->start = 0;
|
---|
701 | e->size = empty_size;
|
---|
702 | }
|
---|
703 | delete_region(e, p, empty_size);
|
---|
704 | }
|
---|
705 |
|
---|
706 | dprintf(stderr, "%s %s() end\n", __FILE__, __FUNCTION__);
|
---|
707 |
|
---|
708 | return 0;
|
---|
709 | }
|
---|
710 |
|
---|
711 | /* return the size of the region starting at p, or EMPTY_SIZE if non
|
---|
712 | existent region. */
|
---|
713 | static size_t get_region_size(void *p)
|
---|
714 | {
|
---|
715 | size_t addr = (size_t)p;
|
---|
716 | BoundEntry *e;
|
---|
717 |
|
---|
718 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
|
---|
719 | e = (BoundEntry *)((char *)e +
|
---|
720 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
721 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
|
---|
722 | addr -= e->start;
|
---|
723 | if (addr > e->size)
|
---|
724 | e = __bound_find_region(e, p);
|
---|
725 | if (e->start != (size_t)p)
|
---|
726 | return EMPTY_SIZE;
|
---|
727 | return e->size;
|
---|
728 | }
|
---|
729 |
|
---|
730 | /* patched memory functions */
|
---|
731 |
|
---|
732 | /* force compiler to perform stores coded up to this point */
|
---|
733 | #define barrier() __asm__ __volatile__ ("": : : "memory")
|
---|
734 |
|
---|
735 | static void install_malloc_hooks(void)
|
---|
736 | {
|
---|
737 | #ifdef CONFIG_TCC_MALLOC_HOOKS
|
---|
738 | saved_malloc_hook = __malloc_hook;
|
---|
739 | saved_free_hook = __free_hook;
|
---|
740 | saved_realloc_hook = __realloc_hook;
|
---|
741 | saved_memalign_hook = __memalign_hook;
|
---|
742 | __malloc_hook = __bound_malloc;
|
---|
743 | __free_hook = __bound_free;
|
---|
744 | __realloc_hook = __bound_realloc;
|
---|
745 | __memalign_hook = __bound_memalign;
|
---|
746 |
|
---|
747 | barrier();
|
---|
748 | #endif
|
---|
749 | }
|
---|
750 |
|
---|
751 | static void restore_malloc_hooks(void)
|
---|
752 | {
|
---|
753 | #ifdef CONFIG_TCC_MALLOC_HOOKS
|
---|
754 | __malloc_hook = saved_malloc_hook;
|
---|
755 | __free_hook = saved_free_hook;
|
---|
756 | __realloc_hook = saved_realloc_hook;
|
---|
757 | __memalign_hook = saved_memalign_hook;
|
---|
758 |
|
---|
759 | barrier();
|
---|
760 | #endif
|
---|
761 | }
|
---|
762 |
|
---|
763 | static void *libc_malloc(size_t size)
|
---|
764 | {
|
---|
765 | void *ptr;
|
---|
766 | restore_malloc_hooks();
|
---|
767 | ptr = malloc(size);
|
---|
768 | install_malloc_hooks();
|
---|
769 | return ptr;
|
---|
770 | }
|
---|
771 |
|
---|
772 | static void libc_free(void *ptr)
|
---|
773 | {
|
---|
774 | restore_malloc_hooks();
|
---|
775 | free(ptr);
|
---|
776 | install_malloc_hooks();
|
---|
777 | }
|
---|
778 |
|
---|
779 | /* XXX: we should use a malloc which ensure that it is unlikely that
|
---|
780 | two malloc'ed data have the same address if 'free' are made in
|
---|
781 | between. */
|
---|
782 | void *__bound_malloc(size_t size, const void *caller)
|
---|
783 | {
|
---|
784 | void *ptr;
|
---|
785 |
|
---|
786 | /* we allocate one more byte to ensure the regions will be
|
---|
787 | separated by at least one byte. With the glibc malloc, it may
|
---|
788 | be in fact not necessary */
|
---|
789 | ptr = libc_malloc(size + 1);
|
---|
790 |
|
---|
791 | if (!ptr)
|
---|
792 | return NULL;
|
---|
793 |
|
---|
794 | dprintf(stderr, "%s, %s calling __bound_new_region(%p, %x)\n",
|
---|
795 | __FILE__, __FUNCTION__, ptr, (unsigned)size);
|
---|
796 |
|
---|
797 | __bound_new_region(ptr, size);
|
---|
798 | return ptr;
|
---|
799 | }
|
---|
800 |
|
---|
801 | void *__bound_memalign(size_t size, size_t align, const void *caller)
|
---|
802 | {
|
---|
803 | void *ptr;
|
---|
804 |
|
---|
805 | restore_malloc_hooks();
|
---|
806 |
|
---|
807 | #ifndef HAVE_MEMALIGN
|
---|
808 | if (align > 4) {
|
---|
809 | /* XXX: handle it ? */
|
---|
810 | ptr = NULL;
|
---|
811 | } else {
|
---|
812 | /* we suppose that malloc aligns to at least four bytes */
|
---|
813 | ptr = malloc(size + 1);
|
---|
814 | }
|
---|
815 | #else
|
---|
816 | /* we allocate one more byte to ensure the regions will be
|
---|
817 | separated by at least one byte. With the glibc malloc, it may
|
---|
818 | be in fact not necessary */
|
---|
819 | ptr = memalign(size + 1, align);
|
---|
820 | #endif
|
---|
821 |
|
---|
822 | install_malloc_hooks();
|
---|
823 |
|
---|
824 | if (!ptr)
|
---|
825 | return NULL;
|
---|
826 |
|
---|
827 | dprintf(stderr, "%s, %s calling __bound_new_region(%p, %x)\n",
|
---|
828 | __FILE__, __FUNCTION__, ptr, (unsigned)size);
|
---|
829 |
|
---|
830 | __bound_new_region(ptr, size);
|
---|
831 | return ptr;
|
---|
832 | }
|
---|
833 |
|
---|
834 | void __bound_free(void *ptr, const void *caller)
|
---|
835 | {
|
---|
836 | if (ptr == NULL)
|
---|
837 | return;
|
---|
838 | if (__bound_delete_region(ptr) != 0)
|
---|
839 | bound_error("freeing invalid region");
|
---|
840 |
|
---|
841 | libc_free(ptr);
|
---|
842 | }
|
---|
843 |
|
---|
844 | void *__bound_realloc(void *ptr, size_t size, const void *caller)
|
---|
845 | {
|
---|
846 | void *ptr1;
|
---|
847 | size_t old_size;
|
---|
848 |
|
---|
849 | if (size == 0) {
|
---|
850 | __bound_free(ptr, caller);
|
---|
851 | return NULL;
|
---|
852 | } else {
|
---|
853 | ptr1 = __bound_malloc(size, caller);
|
---|
854 | if (ptr == NULL || ptr1 == NULL)
|
---|
855 | return ptr1;
|
---|
856 | old_size = get_region_size(ptr);
|
---|
857 | if (old_size == EMPTY_SIZE)
|
---|
858 | bound_error("realloc'ing invalid pointer");
|
---|
859 | memcpy(ptr1, ptr, old_size);
|
---|
860 | __bound_free(ptr, caller);
|
---|
861 | return ptr1;
|
---|
862 | }
|
---|
863 | }
|
---|
864 |
|
---|
865 | #ifndef CONFIG_TCC_MALLOC_HOOKS
|
---|
866 | void *__bound_calloc(size_t nmemb, size_t size)
|
---|
867 | {
|
---|
868 | void *ptr;
|
---|
869 | size = size * nmemb;
|
---|
870 | ptr = __bound_malloc(size, NULL);
|
---|
871 | if (!ptr)
|
---|
872 | return NULL;
|
---|
873 | memset(ptr, 0, size);
|
---|
874 | return ptr;
|
---|
875 | }
|
---|
876 | #endif
|
---|
877 |
|
---|
878 | #if 0
|
---|
879 | static void bound_dump(void)
|
---|
880 | {
|
---|
881 | BoundEntry *page, *e;
|
---|
882 | size_t i, j;
|
---|
883 |
|
---|
884 | fprintf(stderr, "region dump:\n");
|
---|
885 | for(i=0;i<BOUND_T1_SIZE;i++) {
|
---|
886 | page = __bound_t1[i];
|
---|
887 | for(j=0;j<BOUND_T2_SIZE;j++) {
|
---|
888 | e = page + j;
|
---|
889 | /* do not print invalid or empty entries */
|
---|
890 | if (e->size != EMPTY_SIZE && e->start != 0) {
|
---|
891 | fprintf(stderr, "%08x:",
|
---|
892 | (i << (BOUND_T2_BITS + BOUND_T3_BITS)) +
|
---|
893 | (j << BOUND_T3_BITS));
|
---|
894 | do {
|
---|
895 | fprintf(stderr, " %08lx:%08lx", e->start, e->start + e->size);
|
---|
896 | e = e->next;
|
---|
897 | } while (e != NULL);
|
---|
898 | fprintf(stderr, "\n");
|
---|
899 | }
|
---|
900 | }
|
---|
901 | }
|
---|
902 | }
|
---|
903 | #endif
|
---|
904 |
|
---|
905 | /* some useful checked functions */
|
---|
906 |
|
---|
907 | /* check that (p ... p + size - 1) lies inside 'p' region, if any */
|
---|
908 | static void __bound_check(const void *p, size_t size)
|
---|
909 | {
|
---|
910 | if (size == 0)
|
---|
911 | return;
|
---|
912 | p = __bound_ptr_add((void *)p, size - 1);
|
---|
913 | if (p == INVALID_POINTER)
|
---|
914 | bound_error("invalid pointer");
|
---|
915 | }
|
---|
916 |
|
---|
917 | void *__bound_memcpy(void *dst, const void *src, size_t size)
|
---|
918 | {
|
---|
919 | void* p;
|
---|
920 |
|
---|
921 | dprintf(stderr, "%s %s: start, dst=%p src=%p size=%x\n",
|
---|
922 | __FILE__, __FUNCTION__, dst, src, (unsigned)size);
|
---|
923 |
|
---|
924 | __bound_check(dst, size);
|
---|
925 | __bound_check(src, size);
|
---|
926 | /* check also region overlap */
|
---|
927 | if (src >= dst && src < dst + size)
|
---|
928 | bound_error("overlapping regions in memcpy()");
|
---|
929 |
|
---|
930 | p = memcpy(dst, src, size);
|
---|
931 |
|
---|
932 | dprintf(stderr, "%s %s: end, p=%p\n", __FILE__, __FUNCTION__, p);
|
---|
933 | return p;
|
---|
934 | }
|
---|
935 |
|
---|
936 | void *__bound_memmove(void *dst, const void *src, size_t size)
|
---|
937 | {
|
---|
938 | __bound_check(dst, size);
|
---|
939 | __bound_check(src, size);
|
---|
940 | return memmove(dst, src, size);
|
---|
941 | }
|
---|
942 |
|
---|
943 | void *__bound_memset(void *dst, int c, size_t size)
|
---|
944 | {
|
---|
945 | __bound_check(dst, size);
|
---|
946 | return memset(dst, c, size);
|
---|
947 | }
|
---|
948 |
|
---|
949 | /* XXX: could be optimized */
|
---|
950 | int __bound_strlen(const char *s)
|
---|
951 | {
|
---|
952 | const char *p;
|
---|
953 | size_t len;
|
---|
954 |
|
---|
955 | len = 0;
|
---|
956 | for(;;) {
|
---|
957 | p = __bound_ptr_indir1((char *)s, len);
|
---|
958 | if (p == INVALID_POINTER)
|
---|
959 | bound_error("bad pointer in strlen()");
|
---|
960 | if (*p == '\0')
|
---|
961 | break;
|
---|
962 | len++;
|
---|
963 | }
|
---|
964 | return len;
|
---|
965 | }
|
---|
966 |
|
---|
967 | char *__bound_strcpy(char *dst, const char *src)
|
---|
968 | {
|
---|
969 | size_t len;
|
---|
970 | void *p;
|
---|
971 |
|
---|
972 | dprintf(stderr, "%s %s: strcpy start, dst=%p src=%p\n",
|
---|
973 | __FILE__, __FUNCTION__, dst, src);
|
---|
974 | len = __bound_strlen(src);
|
---|
975 | p = __bound_memcpy(dst, src, len + 1);
|
---|
976 | dprintf(stderr, "%s %s: strcpy end, p = %p\n",
|
---|
977 | __FILE__, __FUNCTION__, p);
|
---|
978 | return p;
|
---|
979 | }
|
---|