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| 1 | +/* | |
| 2 | + * Tiny C Memory and bounds checker | |
| 3 | + * | |
| 4 | + * Copyright (c) 2002 Fabrice Bellard | |
| 5 | + * | |
| 6 | + * This library is free software; you can redistribute it and/or | |
| 7 | + * modify it under the terms of the GNU Lesser General Public | |
| 8 | + * License as published by the Free Software Foundation; either | |
| 9 | + * version 2 of the License, or (at your option) any later version. | |
| 10 | + * | |
| 11 | + * This library is distributed in the hope that it will be useful, | |
| 12 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 | + * Lesser General Public License for more details. | |
| 15 | + * | |
| 16 | + * You should have received a copy of the GNU Lesser General Public | |
| 17 | + * License along with this library; if not, write to the Free Software | |
| 18 | + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 19 | + */ | |
| 20 | +#include <stdlib.h> | |
| 21 | +#include <stdio.h> | |
| 22 | +#include <stdarg.h> | |
| 23 | +#include <string.h> | |
| 24 | +#if !defined(__FreeBSD__) && !defined(__DragonFly__) && !defined(__OpenBSD__) | |
| 25 | +#include <malloc.h> | |
| 26 | +#endif | |
| 27 | + | |
| 28 | +//#define BOUND_DEBUG | |
| 29 | + | |
| 30 | +/* define so that bound array is static (faster, but use memory if | |
| 31 | + bound checking not used) */ | |
| 32 | +//#define BOUND_STATIC | |
| 33 | + | |
| 34 | +/* use malloc hooks. Currently the code cannot be reliable if no hooks */ | |
| 35 | +#define CONFIG_TCC_MALLOC_HOOKS | |
| 36 | + | |
| 37 | +#define HAVE_MEMALIGN | |
| 38 | + | |
| 39 | +#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__dietlibc__) \ | |
| 40 | + || defined(__UCLIBC__) || defined(__OpenBSD__) | |
| 41 | +#warning Bound checking not fully supported in this environment. | |
| 42 | +#undef CONFIG_TCC_MALLOC_HOOKS | |
| 43 | +#undef HAVE_MEMALIGN | |
| 44 | +#endif | |
| 45 | + | |
| 46 | +#define BOUND_T1_BITS 13 | |
| 47 | +#define BOUND_T2_BITS 11 | |
| 48 | +#define BOUND_T3_BITS (32 - BOUND_T1_BITS - BOUND_T2_BITS) | |
| 49 | + | |
| 50 | +#define BOUND_T1_SIZE (1 << BOUND_T1_BITS) | |
| 51 | +#define BOUND_T2_SIZE (1 << BOUND_T2_BITS) | |
| 52 | +#define BOUND_T3_SIZE (1 << BOUND_T3_BITS) | |
| 53 | +#define BOUND_E_BITS 4 | |
| 54 | + | |
| 55 | +#define BOUND_T23_BITS (BOUND_T2_BITS + BOUND_T3_BITS) | |
| 56 | +#define BOUND_T23_SIZE (1 << BOUND_T23_BITS) | |
| 57 | + | |
| 58 | + | |
| 59 | +/* this pointer is generated when bound check is incorrect */ | |
| 60 | +#define INVALID_POINTER ((void *)(-2)) | |
| 61 | +/* size of an empty region */ | |
| 62 | +#define EMPTY_SIZE 0xffffffff | |
| 63 | +/* size of an invalid region */ | |
| 64 | +#define INVALID_SIZE 0 | |
| 65 | + | |
| 66 | +typedef struct BoundEntry { | |
| 67 | + unsigned long start; | |
| 68 | + unsigned long size; | |
| 69 | + struct BoundEntry *next; | |
| 70 | + unsigned long is_invalid; /* true if pointers outside region are invalid */ | |
| 71 | +} BoundEntry; | |
| 72 | + | |
| 73 | +/* external interface */ | |
| 74 | +void __bound_init(void); | |
| 75 | +void __bound_new_region(void *p, unsigned long size); | |
| 76 | +int __bound_delete_region(void *p); | |
| 77 | + | |
| 78 | +#define FASTCALL __attribute__((regparm(3))) | |
| 79 | + | |
| 80 | +void *__bound_malloc(size_t size, const void *caller); | |
| 81 | +void *__bound_memalign(size_t size, size_t align, const void *caller); | |
| 82 | +void __bound_free(void *ptr, const void *caller); | |
| 83 | +void *__bound_realloc(void *ptr, size_t size, const void *caller); | |
| 84 | +static void *libc_malloc(size_t size); | |
| 85 | +static void libc_free(void *ptr); | |
| 86 | +static void install_malloc_hooks(void); | |
| 87 | +static void restore_malloc_hooks(void); | |
| 88 | + | |
| 89 | +#ifdef CONFIG_TCC_MALLOC_HOOKS | |
| 90 | +static void *saved_malloc_hook; | |
| 91 | +static void *saved_free_hook; | |
| 92 | +static void *saved_realloc_hook; | |
| 93 | +static void *saved_memalign_hook; | |
| 94 | +#endif | |
| 95 | + | |
| 96 | +/* linker definitions */ | |
| 97 | +extern char _end; | |
| 98 | + | |
| 99 | +/* TCC definitions */ | |
| 100 | +extern char __bounds_start; /* start of static bounds table */ | |
| 101 | +/* error message, just for TCC */ | |
| 102 | +const char *__bound_error_msg; | |
| 103 | + | |
| 104 | +/* runtime error output */ | |
| 105 | +extern void rt_error(unsigned long pc, const char *fmt, ...); | |
| 106 | + | |
| 107 | +#ifdef BOUND_STATIC | |
| 108 | +static BoundEntry *__bound_t1[BOUND_T1_SIZE]; /* page table */ | |
| 109 | +#else | |
| 110 | +static BoundEntry **__bound_t1; /* page table */ | |
| 111 | +#endif | |
| 112 | +static BoundEntry *__bound_empty_t2; /* empty page, for unused pages */ | |
| 113 | +static BoundEntry *__bound_invalid_t2; /* invalid page, for invalid pointers */ | |
| 114 | + | |
| 115 | +static BoundEntry *__bound_find_region(BoundEntry *e1, void *p) | |
| 116 | +{ | |
| 117 | + unsigned long addr, tmp; | |
| 118 | + BoundEntry *e; | |
| 119 | + | |
| 120 | + e = e1; | |
| 121 | + while (e != NULL) { | |
| 122 | + addr = (unsigned long)p; | |
| 123 | + addr -= e->start; | |
| 124 | + if (addr <= e->size) { | |
| 125 | + /* put region at the head */ | |
| 126 | + tmp = e1->start; | |
| 127 | + e1->start = e->start; | |
| 128 | + e->start = tmp; | |
| 129 | + tmp = e1->size; | |
| 130 | + e1->size = e->size; | |
| 131 | + e->size = tmp; | |
| 132 | + return e1; | |
| 133 | + } | |
| 134 | + e = e->next; | |
| 135 | + } | |
| 136 | + /* no entry found: return empty entry or invalid entry */ | |
| 137 | + if (e1->is_invalid) | |
| 138 | + return __bound_invalid_t2; | |
| 139 | + else | |
| 140 | + return __bound_empty_t2; | |
| 141 | +} | |
| 142 | + | |
| 143 | +/* print a bound error message */ | |
| 144 | +static void bound_error(const char *fmt, ...) | |
| 145 | +{ | |
| 146 | + __bound_error_msg = fmt; | |
| 147 | + *(int *)0 = 0; /* force a runtime error */ | |
| 148 | +} | |
| 149 | + | |
| 150 | +static void bound_alloc_error(void) | |
| 151 | +{ | |
| 152 | + bound_error("not enough memory for bound checking code"); | |
| 153 | +} | |
| 154 | + | |
| 155 | +/* currently, tcc cannot compile that because we use GNUC extensions */ | |
| 156 | +#if !defined(__TINYC__) | |
| 157 | + | |
| 158 | +/* return '(p + offset)' for pointer arithmetic (a pointer can reach | |
| 159 | + the end of a region in this case */ | |
| 160 | +void * FASTCALL __bound_ptr_add(void *p, int offset) | |
| 161 | +{ | |
| 162 | + unsigned long addr = (unsigned long)p; | |
| 163 | + BoundEntry *e; | |
| 164 | +#if defined(BOUND_DEBUG) | |
| 165 | + printf("add: 0x%x %d\n", (int)p, offset); | |
| 166 | +#endif | |
| 167 | + | |
| 168 | + e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)]; | |
| 169 | + e = (BoundEntry *)((char *)e + | |
| 170 | + ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & | |
| 171 | + ((BOUND_T2_SIZE - 1) << BOUND_E_BITS))); | |
| 172 | + addr -= e->start; | |
| 173 | + if (addr > e->size) { | |
| 174 | + e = __bound_find_region(e, p); | |
| 175 | + addr = (unsigned long)p - e->start; | |
| 176 | + } | |
| 177 | + addr += offset; | |
| 178 | + if (addr > e->size) | |
| 179 | + return INVALID_POINTER; /* return an invalid pointer */ | |
| 180 | + return p + offset; | |
| 181 | +} | |
| 182 | + | |
| 183 | +/* return '(p + offset)' for pointer indirection (the resulting must | |
| 184 | + be strictly inside the region */ | |
| 185 | +#define BOUND_PTR_INDIR(dsize) \ | |
| 186 | +void * FASTCALL __bound_ptr_indir ## dsize (void *p, int offset) \ | |
| 187 | +{ \ | |
| 188 | + unsigned long addr = (unsigned long)p; \ | |
| 189 | + BoundEntry *e; \ | |
| 190 | + \ | |
| 191 | + e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)]; \ | |
| 192 | + e = (BoundEntry *)((char *)e + \ | |
| 193 | + ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & \ | |
| 194 | + ((BOUND_T2_SIZE - 1) << BOUND_E_BITS))); \ | |
| 195 | + addr -= e->start; \ | |
| 196 | + if (addr > e->size) { \ | |
| 197 | + e = __bound_find_region(e, p); \ | |
| 198 | + addr = (unsigned long)p - e->start; \ | |
| 199 | + } \ | |
| 200 | + addr += offset + dsize; \ | |
| 201 | + if (addr > e->size) \ | |
| 202 | + return INVALID_POINTER; /* return an invalid pointer */ \ | |
| 203 | + return p + offset; \ | |
| 204 | +} | |
| 205 | + | |
| 206 | +#ifdef __i386__ | |
| 207 | +/* return the frame pointer of the caller */ | |
| 208 | +#define GET_CALLER_FP(fp)\ | |
| 209 | +{\ | |
| 210 | + unsigned long *fp1;\ | |
| 211 | + __asm__ __volatile__ ("movl %%ebp,%0" :"=g" (fp1));\ | |
| 212 | + fp = fp1[0];\ | |
| 213 | +} | |
| 214 | +#else | |
| 215 | +#error put code to extract the calling frame pointer | |
| 216 | +#endif | |
| 217 | + | |
| 218 | +/* called when entering a function to add all the local regions */ | |
| 219 | +void FASTCALL __bound_local_new(void *p1) | |
| 220 | +{ | |
| 221 | + unsigned long addr, size, fp, *p = p1; | |
| 222 | + GET_CALLER_FP(fp); | |
| 223 | + for(;;) { | |
| 224 | + addr = p[0]; | |
| 225 | + if (addr == 0) | |
| 226 | + break; | |
| 227 | + addr += fp; | |
| 228 | + size = p[1]; | |
| 229 | + p += 2; | |
| 230 | + __bound_new_region((void *)addr, size); | |
| 231 | + } | |
| 232 | +} | |
| 233 | + | |
| 234 | +/* called when leaving a function to delete all the local regions */ | |
| 235 | +void FASTCALL __bound_local_delete(void *p1) | |
| 236 | +{ | |
| 237 | + unsigned long addr, fp, *p = p1; | |
| 238 | + GET_CALLER_FP(fp); | |
| 239 | + for(;;) { | |
| 240 | + addr = p[0]; | |
| 241 | + if (addr == 0) | |
| 242 | + break; | |
| 243 | + addr += fp; | |
| 244 | + p += 2; | |
| 245 | + __bound_delete_region((void *)addr); | |
| 246 | + } | |
| 247 | +} | |
| 248 | + | |
| 249 | +#else | |
| 250 | + | |
| 251 | +void __bound_local_new(void *p) | |
| 252 | +{ | |
| 253 | +} | |
| 254 | +void __bound_local_delete(void *p) | |
| 255 | +{ | |
| 256 | +} | |
| 257 | + | |
| 258 | +void *__bound_ptr_add(void *p, int offset) | |
| 259 | +{ | |
| 260 | + return p + offset; | |
| 261 | +} | |
| 262 | + | |
| 263 | +#define BOUND_PTR_INDIR(dsize) \ | |
| 264 | +void *__bound_ptr_indir ## dsize (void *p, int offset) \ | |
| 265 | +{ \ | |
| 266 | + return p + offset; \ | |
| 267 | +} | |
| 268 | +#endif | |
| 269 | + | |
| 270 | +BOUND_PTR_INDIR(1) | |
| 271 | +BOUND_PTR_INDIR(2) | |
| 272 | +BOUND_PTR_INDIR(4) | |
| 273 | +BOUND_PTR_INDIR(8) | |
| 274 | +BOUND_PTR_INDIR(12) | |
| 275 | +BOUND_PTR_INDIR(16) | |
| 276 | + | |
| 277 | +static BoundEntry *__bound_new_page(void) | |
| 278 | +{ | |
| 279 | + BoundEntry *page; | |
| 280 | + int i; | |
| 281 | + | |
| 282 | + page = libc_malloc(sizeof(BoundEntry) * BOUND_T2_SIZE); | |
| 283 | + if (!page) | |
| 284 | + bound_alloc_error(); | |
| 285 | + for(i=0;i<BOUND_T2_SIZE;i++) { | |
| 286 | + /* put empty entries */ | |
| 287 | + page[i].start = 0; | |
| 288 | + page[i].size = EMPTY_SIZE; | |
| 289 | + page[i].next = NULL; | |
| 290 | + page[i].is_invalid = 0; | |
| 291 | + } | |
| 292 | + return page; | |
| 293 | +} | |
| 294 | + | |
| 295 | +/* currently we use malloc(). Should use bound_new_page() */ | |
| 296 | +static BoundEntry *bound_new_entry(void) | |
| 297 | +{ | |
| 298 | + BoundEntry *e; | |
| 299 | + e = libc_malloc(sizeof(BoundEntry)); | |
| 300 | + return e; | |
| 301 | +} | |
| 302 | + | |
| 303 | +static void bound_free_entry(BoundEntry *e) | |
| 304 | +{ | |
| 305 | + libc_free(e); | |
| 306 | +} | |
| 307 | + | |
| 308 | +static inline BoundEntry *get_page(int index) | |
| 309 | +{ | |
| 310 | + BoundEntry *page; | |
| 311 | + page = __bound_t1[index]; | |
| 312 | + if (page == __bound_empty_t2 || page == __bound_invalid_t2) { | |
| 313 | + /* create a new page if necessary */ | |
| 314 | + page = __bound_new_page(); | |
| 315 | + __bound_t1[index] = page; | |
| 316 | + } | |
| 317 | + return page; | |
| 318 | +} | |
| 319 | + | |
| 320 | +/* mark a region as being invalid (can only be used during init) */ | |
| 321 | +static void mark_invalid(unsigned long addr, unsigned long size) | |
| 322 | +{ | |
| 323 | + unsigned long start, end; | |
| 324 | + BoundEntry *page; | |
| 325 | + int t1_start, t1_end, i, j, t2_start, t2_end; | |
| 326 | + | |
| 327 | + start = addr; | |
| 328 | + end = addr + size; | |
| 329 | + | |
| 330 | + t2_start = (start + BOUND_T3_SIZE - 1) >> BOUND_T3_BITS; | |
| 331 | + if (end != 0) | |
| 332 | + t2_end = end >> BOUND_T3_BITS; | |
| 333 | + else | |
| 334 | + t2_end = 1 << (BOUND_T1_BITS + BOUND_T2_BITS); | |
| 335 | + | |
| 336 | +#if 0 | |
| 337 | + printf("mark_invalid: start = %x %x\n", t2_start, t2_end); | |
| 338 | +#endif | |
| 339 | + | |
| 340 | + /* first we handle full pages */ | |
| 341 | + t1_start = (t2_start + BOUND_T2_SIZE - 1) >> BOUND_T2_BITS; | |
| 342 | + t1_end = t2_end >> BOUND_T2_BITS; | |
| 343 | + | |
| 344 | + i = t2_start & (BOUND_T2_SIZE - 1); | |
| 345 | + j = t2_end & (BOUND_T2_SIZE - 1); | |
| 346 | + | |
| 347 | + if (t1_start == t1_end) { | |
| 348 | + page = get_page(t2_start >> BOUND_T2_BITS); | |
| 349 | + for(; i < j; i++) { | |
| 350 | + page[i].size = INVALID_SIZE; | |
| 351 | + page[i].is_invalid = 1; | |
| 352 | + } | |
| 353 | + } else { | |
| 354 | + if (i > 0) { | |
| 355 | + page = get_page(t2_start >> BOUND_T2_BITS); | |
| 356 | + for(; i < BOUND_T2_SIZE; i++) { | |
| 357 | + page[i].size = INVALID_SIZE; | |
| 358 | + page[i].is_invalid = 1; | |
| 359 | + } | |
| 360 | + } | |
| 361 | + for(i = t1_start; i < t1_end; i++) { | |
| 362 | + __bound_t1[i] = __bound_invalid_t2; | |
| 363 | + } | |
| 364 | + if (j != 0) { | |
| 365 | + page = get_page(t1_end); | |
| 366 | + for(i = 0; i < j; i++) { | |
| 367 | + page[i].size = INVALID_SIZE; | |
| 368 | + page[i].is_invalid = 1; | |
| 369 | + } | |
| 370 | + } | |
| 371 | + } | |
| 372 | +} | |
| 373 | + | |
| 374 | +void __bound_init(void) | |
| 375 | +{ | |
| 376 | + int i; | |
| 377 | + BoundEntry *page; | |
| 378 | + unsigned long start, size; | |
| 379 | + int *p; | |
| 380 | + | |
| 381 | + /* save malloc hooks and install bound check hooks */ | |
| 382 | + install_malloc_hooks(); | |
| 383 | + | |
| 384 | +#ifndef BOUND_STATIC | |
| 385 | + __bound_t1 = libc_malloc(BOUND_T1_SIZE * sizeof(BoundEntry *)); | |
| 386 | + if (!__bound_t1) | |
| 387 | + bound_alloc_error(); | |
| 388 | +#endif | |
| 389 | + __bound_empty_t2 = __bound_new_page(); | |
| 390 | + for(i=0;i<BOUND_T1_SIZE;i++) { | |
| 391 | + __bound_t1[i] = __bound_empty_t2; | |
| 392 | + } | |
| 393 | + | |
| 394 | + page = __bound_new_page(); | |
| 395 | + for(i=0;i<BOUND_T2_SIZE;i++) { | |
| 396 | + /* put invalid entries */ | |
| 397 | + page[i].start = 0; | |
| 398 | + page[i].size = INVALID_SIZE; | |
| 399 | + page[i].next = NULL; | |
| 400 | + page[i].is_invalid = 1; | |
| 401 | + } | |
| 402 | + __bound_invalid_t2 = page; | |
| 403 | + | |
| 404 | + /* invalid pointer zone */ | |
| 405 | + start = (unsigned long)INVALID_POINTER & ~(BOUND_T23_SIZE - 1); | |
| 406 | + size = BOUND_T23_SIZE; | |
| 407 | + mark_invalid(start, size); | |
| 408 | + | |
| 409 | +#if !defined(__TINYC__) && defined(CONFIG_TCC_MALLOC_HOOKS) | |
| 410 | + /* malloc zone is also marked invalid. can only use that with | |
| 411 | + hooks because all libs should use the same malloc. The solution | |
| 412 | + would be to build a new malloc for tcc. */ | |
| 413 | + start = (unsigned long)&_end; | |
| 414 | + size = 128 * 0x100000; | |
| 415 | + mark_invalid(start, size); | |
| 416 | +#endif | |
| 417 | + | |
| 418 | + /* add all static bound check values */ | |
| 419 | + p = (int *)&__bounds_start; | |
| 420 | + while (p[0] != 0) { | |
| 421 | + __bound_new_region((void *)p[0], p[1]); | |
| 422 | + p += 2; | |
| 423 | + } | |
| 424 | +} | |
| 425 | + | |
| 426 | +static inline void add_region(BoundEntry *e, | |
| 427 | + unsigned long start, unsigned long size) | |
| 428 | +{ | |
| 429 | + BoundEntry *e1; | |
| 430 | + if (e->start == 0) { | |
| 431 | + /* no region : add it */ | |
| 432 | + e->start = start; | |
| 433 | + e->size = size; | |
| 434 | + } else { | |
| 435 | + /* already regions in the list: add it at the head */ | |
| 436 | + e1 = bound_new_entry(); | |
| 437 | + e1->start = e->start; | |
| 438 | + e1->size = e->size; | |
| 439 | + e1->next = e->next; | |
| 440 | + e->start = start; | |
| 441 | + e->size = size; | |
| 442 | + e->next = e1; | |
| 443 | + } | |
| 444 | +} | |
| 445 | + | |
| 446 | +/* create a new region. It should not already exist in the region list */ | |
| 447 | +void __bound_new_region(void *p, unsigned long size) | |
| 448 | +{ | |
| 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(t2_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 | +static void install_malloc_hooks(void) | |
| 652 | +{ | |
| 653 | +#ifdef CONFIG_TCC_MALLOC_HOOKS | |
| 654 | + saved_malloc_hook = __malloc_hook; | |
| 655 | + saved_free_hook = __free_hook; | |
| 656 | + saved_realloc_hook = __realloc_hook; | |
| 657 | + saved_memalign_hook = __memalign_hook; | |
| 658 | + __malloc_hook = __bound_malloc; | |
| 659 | + __free_hook = __bound_free; | |
| 660 | + __realloc_hook = __bound_realloc; | |
| 661 | + __memalign_hook = __bound_memalign; | |
| 662 | +#endif | |
| 663 | +} | |
| 664 | + | |
| 665 | +static void restore_malloc_hooks(void) | |
| 666 | +{ | |
| 667 | +#ifdef CONFIG_TCC_MALLOC_HOOKS | |
| 668 | + __malloc_hook = saved_malloc_hook; | |
| 669 | + __free_hook = saved_free_hook; | |
| 670 | + __realloc_hook = saved_realloc_hook; | |
| 671 | + __memalign_hook = saved_memalign_hook; | |
| 672 | +#endif | |
| 673 | +} | |
| 674 | + | |
| 675 | +static void *libc_malloc(size_t size) | |
| 676 | +{ | |
| 677 | + void *ptr; | |
| 678 | + restore_malloc_hooks(); | |
| 679 | + ptr = malloc(size); | |
| 680 | + install_malloc_hooks(); | |
| 681 | + return ptr; | |
| 682 | +} | |
| 683 | + | |
| 684 | +static void libc_free(void *ptr) | |
| 685 | +{ | |
| 686 | + restore_malloc_hooks(); | |
| 687 | + free(ptr); | |
| 688 | + install_malloc_hooks(); | |
| 689 | +} | |
| 690 | + | |
| 691 | +/* XXX: we should use a malloc which ensure that it is unlikely that | |
| 692 | + two malloc'ed data have the same address if 'free' are made in | |
| 693 | + between. */ | |
| 694 | +void *__bound_malloc(size_t size, const void *caller) | |
| 695 | +{ | |
| 696 | + void *ptr; | |
| 697 | + | |
| 698 | + /* we allocate one more byte to ensure the regions will be | |
| 699 | + separated by at least one byte. With the glibc malloc, it may | |
| 700 | + be in fact not necessary */ | |
| 701 | + ptr = libc_malloc(size + 1); | |
| 702 | + | |
| 703 | + if (!ptr) | |
| 704 | + return NULL; | |
| 705 | + __bound_new_region(ptr, size); | |
| 706 | + return ptr; | |
| 707 | +} | |
| 708 | + | |
| 709 | +void *__bound_memalign(size_t size, size_t align, const void *caller) | |
| 710 | +{ | |
| 711 | + void *ptr; | |
| 712 | + | |
| 713 | + restore_malloc_hooks(); | |
| 714 | + | |
| 715 | +#ifndef HAVE_MEMALIGN | |
| 716 | + if (align > 4) { | |
| 717 | + /* XXX: handle it ? */ | |
| 718 | + ptr = NULL; | |
| 719 | + } else { | |
| 720 | + /* we suppose that malloc aligns to at least four bytes */ | |
| 721 | + ptr = malloc(size + 1); | |
| 722 | + } | |
| 723 | +#else | |
| 724 | + /* we allocate one more byte to ensure the regions will be | |
| 725 | + separated by at least one byte. With the glibc malloc, it may | |
| 726 | + be in fact not necessary */ | |
| 727 | + ptr = memalign(size + 1, align); | |
| 728 | +#endif | |
| 729 | + | |
| 730 | + install_malloc_hooks(); | |
| 731 | + | |
| 732 | + if (!ptr) | |
| 733 | + return NULL; | |
| 734 | + __bound_new_region(ptr, size); | |
| 735 | + return ptr; | |
| 736 | +} | |
| 737 | + | |
| 738 | +void __bound_free(void *ptr, const void *caller) | |
| 739 | +{ | |
| 740 | + if (ptr == NULL) | |
| 741 | + return; | |
| 742 | + if (__bound_delete_region(ptr) != 0) | |
| 743 | + bound_error("freeing invalid region"); | |
| 744 | + | |
| 745 | + libc_free(ptr); | |
| 746 | +} | |
| 747 | + | |
| 748 | +void *__bound_realloc(void *ptr, size_t size, const void *caller) | |
| 749 | +{ | |
| 750 | + void *ptr1; | |
| 751 | + int old_size; | |
| 752 | + | |
| 753 | + if (size == 0) { | |
| 754 | + __bound_free(ptr, caller); | |
| 755 | + return NULL; | |
| 756 | + } else { | |
| 757 | + ptr1 = __bound_malloc(size, caller); | |
| 758 | + if (ptr == NULL || ptr1 == NULL) | |
| 759 | + return ptr1; | |
| 760 | + old_size = get_region_size(ptr); | |
| 761 | + if (old_size == EMPTY_SIZE) | |
| 762 | + bound_error("realloc'ing invalid pointer"); | |
| 763 | + memcpy(ptr1, ptr, old_size); | |
| 764 | + __bound_free(ptr, caller); | |
| 765 | + return ptr1; | |
| 766 | + } | |
| 767 | +} | |
| 768 | + | |
| 769 | +#ifndef CONFIG_TCC_MALLOC_HOOKS | |
| 770 | +void *__bound_calloc(size_t nmemb, size_t size) | |
| 771 | +{ | |
| 772 | + void *ptr; | |
| 773 | + size = size * nmemb; | |
| 774 | + ptr = __bound_malloc(size, NULL); | |
| 775 | + if (!ptr) | |
| 776 | + return NULL; | |
| 777 | + memset(ptr, 0, size); | |
| 778 | + return ptr; | |
| 779 | +} | |
| 780 | +#endif | |
| 781 | + | |
| 782 | +#if 0 | |
| 783 | +static void bound_dump(void) | |
| 784 | +{ | |
| 785 | + BoundEntry *page, *e; | |
| 786 | + int i, j; | |
| 787 | + | |
| 788 | + printf("region dump:\n"); | |
| 789 | + for(i=0;i<BOUND_T1_SIZE;i++) { | |
| 790 | + page = __bound_t1[i]; | |
| 791 | + for(j=0;j<BOUND_T2_SIZE;j++) { | |
| 792 | + e = page + j; | |
| 793 | + /* do not print invalid or empty entries */ | |
| 794 | + if (e->size != EMPTY_SIZE && e->start != 0) { | |
| 795 | + printf("%08x:", | |
| 796 | + (i << (BOUND_T2_BITS + BOUND_T3_BITS)) + | |
| 797 | + (j << BOUND_T3_BITS)); | |
| 798 | + do { | |
| 799 | + printf(" %08lx:%08lx", e->start, e->start + e->size); | |
| 800 | + e = e->next; | |
| 801 | + } while (e != NULL); | |
| 802 | + printf("\n"); | |
| 803 | + } | |
| 804 | + } | |
| 805 | + } | |
| 806 | +} | |
| 807 | +#endif | |
| 808 | + | |
| 809 | +/* some useful checked functions */ | |
| 810 | + | |
| 811 | +/* check that (p ... p + size - 1) lies inside 'p' region, if any */ | |
| 812 | +static void __bound_check(const void *p, size_t size) | |
| 813 | +{ | |
| 814 | + if (size == 0) | |
| 815 | + return; | |
| 816 | + p = __bound_ptr_add((void *)p, size); | |
| 817 | + if (p == INVALID_POINTER) | |
| 818 | + bound_error("invalid pointer"); | |
| 819 | +} | |
| 820 | + | |
| 821 | +void *__bound_memcpy(void *dst, const void *src, size_t size) | |
| 822 | +{ | |
| 823 | + __bound_check(dst, size); | |
| 824 | + __bound_check(src, size); | |
| 825 | + /* check also region overlap */ | |
| 826 | + if (src >= dst && src < dst + size) | |
| 827 | + bound_error("overlapping regions in memcpy()"); | |
| 828 | + return memcpy(dst, src, size); | |
| 829 | +} | |
| 830 | + | |
| 831 | +void *__bound_memmove(void *dst, const void *src, size_t size) | |
| 832 | +{ | |
| 833 | + __bound_check(dst, size); | |
| 834 | + __bound_check(src, size); | |
| 835 | + return memmove(dst, src, size); | |
| 836 | +} | |
| 837 | + | |
| 838 | +void *__bound_memset(void *dst, int c, size_t size) | |
| 839 | +{ | |
| 840 | + __bound_check(dst, size); | |
| 841 | + return memset(dst, c, size); | |
| 842 | +} | |
| 843 | + | |
| 844 | +/* XXX: could be optimized */ | |
| 845 | +int __bound_strlen(const char *s) | |
| 846 | +{ | |
| 847 | + const char *p; | |
| 848 | + int len; | |
| 849 | + | |
| 850 | + len = 0; | |
| 851 | + for(;;) { | |
| 852 | + p = __bound_ptr_indir1((char *)s, len); | |
| 853 | + if (p == INVALID_POINTER) | |
| 854 | + bound_error("bad pointer in strlen()"); | |
| 855 | + if (*p == '\0') | |
| 856 | + break; | |
| 857 | + len++; | |
| 858 | + } | |
| 859 | + return len; | |
| 860 | +} | |
| 861 | + | |
| 862 | +char *__bound_strcpy(char *dst, const char *src) | |
| 863 | +{ | |
| 864 | + int len; | |
| 865 | + len = __bound_strlen(src); | |
| 866 | + return __bound_memcpy(dst, src, len + 1); | |
| 867 | +} | |
| 868 | + | |