lib/bcheck.c

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