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