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 #ifdef __i386__
 212 /* return the frame pointer of the caller */
 213 #define GET_CALLER_FP(fp)\
 214 {\
 215     unsigned long *fp1;\
 216     __asm__ __volatile__ ("movl %%ebp,%0" :"=g" (fp1));\
 217     fp = fp1[0];\
 218 }
 219 #else
 220 #error put code to extract the calling frame pointer
 221 #endif
 222
 223 /* called when entering a function to add all the local regions */
 224 void FASTCALL __bound_local_new(void *p1)
 225 {
 226     unsigned long addr, size, fp, *p = p1;
 227     GET_CALLER_FP(fp);
 228     for(;;) {
 229         addr = p[0];
 230         if (addr == 0)
 231             break;
 232         addr += fp;
 233         size = p[1];
 234         p += 2;
 235         __bound_new_region((void *)addr, size);
 236     }
 237 }
 238
 239 /* called when leaving a function to delete all the local regions */
 240 void FASTCALL __bound_local_delete(void *p1)
 241 {
 242     unsigned long addr, fp, *p = p1;
 243     GET_CALLER_FP(fp);
 244     for(;;) {
 245         addr = p[0];
 246         if (addr == 0)
 247             break;
 248         addr += fp;
 249         p += 2;
 250         __bound_delete_region((void *)addr);
 251     }
 252 }
 253
 254 static BoundEntry *__bound_new_page(void)
 255 {
 256     BoundEntry *page;
 257     int i;
 258
 259     page = libc_malloc(sizeof(BoundEntry) * BOUND_T2_SIZE);
 260     if (!page)
 261         bound_alloc_error();
 262     for(i=0;i<BOUND_T2_SIZE;i++) {
 263         /* put empty entries */
 264         page[i].start = 0;
 265         page[i].size = EMPTY_SIZE;
 266         page[i].next = NULL;
 267         page[i].is_invalid = 0;
 268     }
 269     return page;
 270 }
 271
 272 /* currently we use malloc(). Should use bound_new_page() */
 273 static BoundEntry *bound_new_entry(void)
 274 {
 275     BoundEntry *e;
 276     e = libc_malloc(sizeof(BoundEntry));
 277     return e;
 278 }
 279
 280 static void bound_free_entry(BoundEntry *e)
 281 {
 282     libc_free(e);
 283 }
 284
 285 static inline BoundEntry *get_page(int index)
 286 {
 287     BoundEntry *page;
 288     page = __bound_t1[index];
 289     if (page == __bound_empty_t2 || page == __bound_invalid_t2) {
 290         /* create a new page if necessary */
 291         page = __bound_new_page();
 292         __bound_t1[index] = page;
 293     }
 294     return page;
 295 }
 296
 297 /* mark a region as being invalid (can only be used during init) */
 298 static void mark_invalid(unsigned long addr, unsigned long size)
 299 {
 300     unsigned long start, end;
 301     BoundEntry *page;
 302     int t1_start, t1_end, i, j, t2_start, t2_end;
 303
 304     start = addr;
 305     end = addr + size;
 306
 307     t2_start = (start + BOUND_T3_SIZE - 1) >> BOUND_T3_BITS;
 308     if (end != 0)
 309         t2_end = end >> BOUND_T3_BITS;
 310     else
 311         t2_end = 1 << (BOUND_T1_BITS + BOUND_T2_BITS);
 312
 313 #if 0
 314     printf("mark_invalid: start = %x %x\n", t2_start, t2_end);
 315 #endif
 316
 317     /* first we handle full pages */
 318     t1_start = (t2_start + BOUND_T2_SIZE - 1) >> BOUND_T2_BITS;
 319     t1_end = t2_end >> BOUND_T2_BITS;
 320
 321     i = t2_start & (BOUND_T2_SIZE - 1);
 322     j = t2_end & (BOUND_T2_SIZE - 1);
 323
 324     if (t1_start == t1_end) {
 325         page = get_page(t2_start >> BOUND_T2_BITS);
 326         for(; i < j; i++) {
 327             page[i].size = INVALID_SIZE;
 328             page[i].is_invalid = 1;
 329         }
 330     } else {
 331         if (i > 0) {
 332             page = get_page(t2_start >> BOUND_T2_BITS);
 333             for(; i < BOUND_T2_SIZE; i++) {
 334                 page[i].size = INVALID_SIZE;
 335                 page[i].is_invalid = 1;
 336             }
 337         }
 338         for(i = t1_start; i < t1_end; i++) {
 339             __bound_t1[i] = __bound_invalid_t2;
 340         }
 341         if (j != 0) {
 342             page = get_page(t1_end);
 343             for(i = 0; i < j; i++) {
 344                 page[i].size = INVALID_SIZE;
 345                 page[i].is_invalid = 1;
 346             }
 347         }
 348     }
 349 }
 350
 351 void __bound_init(void)
 352 {
 353     int i;
 354     BoundEntry *page;
 355     unsigned long start, size;
 356     int *p;
 357
 358     /* save malloc hooks and install bound check hooks */
 359     install_malloc_hooks();
 360
 361 #ifndef BOUND_STATIC
 362     __bound_t1 = libc_malloc(BOUND_T1_SIZE * sizeof(BoundEntry *));
 363     if (!__bound_t1)
 364         bound_alloc_error();
 365 #endif
 366     __bound_empty_t2 = __bound_new_page();
 367     for(i=0;i<BOUND_T1_SIZE;i++) {
 368         __bound_t1[i] = __bound_empty_t2;
 369     }
 370
 371     page = __bound_new_page();
 372     for(i=0;i<BOUND_T2_SIZE;i++) {
 373         /* put invalid entries */
 374         page[i].start = 0;
 375         page[i].size = INVALID_SIZE;
 376         page[i].next = NULL;
 377         page[i].is_invalid = 1;
 378     }
 379     __bound_invalid_t2 = page;
 380
 381     /* invalid pointer zone */
 382     start = (unsigned long)INVALID_POINTER & ~(BOUND_T23_SIZE - 1);
 383     size = BOUND_T23_SIZE;
 384     mark_invalid(start, size);
 385
 386 #if !defined(__TINYC__) && defined(CONFIG_TCC_MALLOC_HOOKS)
 387     /* malloc zone is also marked invalid. can only use that with
 388        hooks because all libs should use the same malloc. The solution
 389        would be to build a new malloc for tcc. */
 390     start = (unsigned long)&_end;
 391     size = 128 * 0x100000;
 392     mark_invalid(start, size);
 393 #endif
 394
 395     /* add all static bound check values */
 396     p = (int *)&__bounds_start;
 397     while (p[0] != 0) {
 398         __bound_new_region((void *)p[0], p[1]);
 399         p += 2;
 400     }
 401 }
 402
 403 void __bound_exit(void)
 404 {
 405     restore_malloc_hooks();
 406 }
 407
 408 static inline void add_region(BoundEntry *e,
 409                               unsigned long start, unsigned long size)
 410 {
 411     BoundEntry *e1;
 412     if (e->start == 0) {
 413         /* no region : add it */
 414         e->start = start;
 415         e->size = size;
 416     } else {
 417         /* already regions in the list: add it at the head */
 418         e1 = bound_new_entry();
 419         e1->start = e->start;
 420         e1->size = e->size;
 421         e1->next = e->next;
 422         e->start = start;
 423         e->size = size;
 424         e->next = e1;
 425     }
 426 }
 427
 428 /* create a new region. It should not already exist in the region list */
 429 void __bound_new_region(void *p, unsigned long size)
 430 {
 431     unsigned long start, end;
 432     BoundEntry *page, *e, *e2;
 433     int t1_start, t1_end, i, t2_start, t2_end;
 434
 435     start = (unsigned long)p;
 436     end = start + size;
 437     t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
 438     t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
 439
 440     /* start */
 441     page = get_page(t1_start);
 442     t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
 443         ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
 444     t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
 445         ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
 446 #ifdef BOUND_DEBUG
 447     printf("new %lx %lx %x %x %x %x\n",
 448            start, end, t1_start, t1_end, t2_start, t2_end);
 449 #endif
 450
 451     e = (BoundEntry *)((char *)page + t2_start);
 452     add_region(e, start, size);
 453
 454     if (t1_end == t1_start) {
 455         /* same ending page */
 456         e2 = (BoundEntry *)((char *)page + t2_end);
 457         if (e2 > e) {
 458             e++;
 459             for(;e<e2;e++) {
 460                 e->start = start;
 461                 e->size = size;
 462             }
 463             add_region(e, start, size);
 464         }
 465     } else {
 466         /* mark until end of page */
 467         e2 = page + BOUND_T2_SIZE;
 468         e++;
 469         for(;e<e2;e++) {
 470             e->start = start;
 471             e->size = size;
 472         }
 473         /* mark intermediate pages, if any */
 474         for(i=t1_start+1;i<t1_end;i++) {
 475             page = get_page(i);
 476             e2 = page + BOUND_T2_SIZE;
 477             for(e=page;e<e2;e++) {
 478                 e->start = start;
 479                 e->size = size;
 480             }
 481         }
 482         /* last page */
 483         page = get_page(t1_end);
 484         e2 = (BoundEntry *)((char *)page + t2_end);
 485         for(e=page;e<e2;e++) {
 486             e->start = start;
 487             e->size = size;
 488         }
 489         add_region(e, start, size);
 490     }
 491 }
 492
 493 /* delete a region */
 494 static inline void delete_region(BoundEntry *e,
 495                                  void *p, unsigned long empty_size)
 496 {
 497     unsigned long addr;
 498     BoundEntry *e1;
 499
 500     addr = (unsigned long)p;
 501     addr -= e->start;
 502     if (addr <= e->size) {
 503         /* region found is first one */
 504         e1 = e->next;
 505         if (e1 == NULL) {
 506             /* no more region: mark it empty */
 507             e->start = 0;
 508             e->size = empty_size;
 509         } else {
 510             /* copy next region in head */
 511             e->start = e1->start;
 512             e->size = e1->size;
 513             e->next = e1->next;
 514             bound_free_entry(e1);
 515         }
 516     } else {
 517         /* find the matching region */
 518         for(;;) {
 519             e1 = e;
 520             e = e->next;
 521             /* region not found: do nothing */
 522             if (e == NULL)
 523                 break;
 524             addr = (unsigned long)p - e->start;
 525             if (addr <= e->size) {
 526                 /* found: remove entry */
 527                 e1->next = e->next;
 528                 bound_free_entry(e);
 529                 break;
 530             }
 531         }
 532     }
 533 }
 534
 535 /* WARNING: 'p' must be the starting point of the region. */
 536 /* return non zero if error */
 537 int __bound_delete_region(void *p)
 538 {
 539     unsigned long start, end, addr, size, empty_size;
 540     BoundEntry *page, *e, *e2;
 541     int t1_start, t1_end, t2_start, t2_end, i;
 542
 543     start = (unsigned long)p;
 544     t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
 545     t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
 546         ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
 547
 548     /* find region size */
 549     page = __bound_t1[t1_start];
 550     e = (BoundEntry *)((char *)page + t2_start);
 551     addr = start - e->start;
 552     if (addr > e->size)
 553         e = __bound_find_region(e, p);
 554     /* test if invalid region */
 555     if (e->size == EMPTY_SIZE || (unsigned long)p != e->start)
 556         return -1;
 557     /* compute the size we put in invalid regions */
 558     if (e->is_invalid)
 559         empty_size = INVALID_SIZE;
 560     else
 561         empty_size = EMPTY_SIZE;
 562     size = e->size;
 563     end = start + size;
 564
 565     /* now we can free each entry */
 566     t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
 567     t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
 568         ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
 569
 570     delete_region(e, p, empty_size);
 571     if (t1_end == t1_start) {
 572         /* same ending page */
 573         e2 = (BoundEntry *)((char *)page + t2_end);
 574         if (e2 > e) {
 575             e++;
 576             for(;e<e2;e++) {
 577                 e->start = 0;
 578                 e->size = empty_size;
 579             }
 580             delete_region(e, p, empty_size);
 581         }
 582     } else {
 583         /* mark until end of page */
 584         e2 = page + BOUND_T2_SIZE;
 585         e++;
 586         for(;e<e2;e++) {
 587             e->start = 0;
 588             e->size = empty_size;
 589         }
 590         /* mark intermediate pages, if any */
 591         /* XXX: should free them */
 592         for(i=t1_start+1;i<t1_end;i++) {
 593             page = get_page(i);
 594             e2 = page + BOUND_T2_SIZE;
 595             for(e=page;e<e2;e++) {
 596                 e->start = 0;
 597                 e->size = empty_size;
 598             }
 599         }
 600         /* last page */
 601         page = get_page(t2_end);
 602         e2 = (BoundEntry *)((char *)page + t2_end);
 603         for(e=page;e<e2;e++) {
 604             e->start = 0;
 605             e->size = empty_size;
 606         }
 607         delete_region(e, p, empty_size);
 608     }
 609     return 0;
 610 }
 611
 612 /* return the size of the region starting at p, or EMPTY_SIZE if non
 613    existant region. */
 614 static unsigned long get_region_size(void *p)
 615 {
 616     unsigned long addr = (unsigned long)p;
 617     BoundEntry *e;
 618
 619     e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
 620     e = (BoundEntry *)((char *)e +
 621                        ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &
 622                         ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
 623     addr -= e->start;
 624     if (addr > e->size)
 625         e = __bound_find_region(e, p);
 626     if (e->start != (unsigned long)p)
 627         return EMPTY_SIZE;
 628     return e->size;
 629 }
 630
 631 /* patched memory functions */
 632
 633 static void install_malloc_hooks(void)
 634 {
 635 #ifdef CONFIG_TCC_MALLOC_HOOKS
 636     saved_malloc_hook = __malloc_hook;
 637     saved_free_hook = __free_hook;
 638     saved_realloc_hook = __realloc_hook;
 639     saved_memalign_hook = __memalign_hook;
 640     __malloc_hook = __bound_malloc;
 641     __free_hook = __bound_free;
 642     __realloc_hook = __bound_realloc;
 643     __memalign_hook = __bound_memalign;
 644 #endif
 645 }
 646
 647 static void restore_malloc_hooks(void)
 648 {
 649 #ifdef CONFIG_TCC_MALLOC_HOOKS
 650     __malloc_hook = saved_malloc_hook;
 651     __free_hook = saved_free_hook;
 652     __realloc_hook = saved_realloc_hook;
 653     __memalign_hook = saved_memalign_hook;
 654 #endif
 655 }
 656
 657 static void *libc_malloc(size_t size)
 658 {
 659     void *ptr;
 660     restore_malloc_hooks();
 661     ptr = malloc(size);
 662     install_malloc_hooks();
 663     return ptr;
 664 }
 665
 666 static void libc_free(void *ptr)
 667 {
 668     restore_malloc_hooks();
 669     free(ptr);
 670     install_malloc_hooks();
 671 }
 672
 673 /* XXX: we should use a malloc which ensure that it is unlikely that
 674    two malloc'ed data have the same address if 'free' are made in
 675    between. */
 676 void *__bound_malloc(size_t size, const void *caller)
 677 {
 678     void *ptr;
 679
 680     /* we allocate one more byte to ensure the regions will be
 681        separated by at least one byte. With the glibc malloc, it may
 682        be in fact not necessary */
 683     ptr = libc_malloc(size + 1);
 684
 685     if (!ptr)
 686         return NULL;
 687     __bound_new_region(ptr, size);
 688     return ptr;
 689 }
 690
 691 void *__bound_memalign(size_t size, size_t align, const void *caller)
 692 {
 693     void *ptr;
 694
 695     restore_malloc_hooks();
 696
 697 #ifndef HAVE_MEMALIGN
 698     if (align > 4) {
 699         /* XXX: handle it ? */
 700         ptr = NULL;
 701     } else {
 702         /* we suppose that malloc aligns to at least four bytes */
 703         ptr = malloc(size + 1);
 704     }
 705 #else
 706     /* we allocate one more byte to ensure the regions will be
 707        separated by at least one byte. With the glibc malloc, it may
 708        be in fact not necessary */
 709     ptr = memalign(size + 1, align);
 710 #endif
 711
 712     install_malloc_hooks();
 713
 714     if (!ptr)
 715         return NULL;
 716     __bound_new_region(ptr, size);
 717     return ptr;
 718 }
 719
 720 void __bound_free(void *ptr, const void *caller)
 721 {
 722     if (ptr == NULL)
 723         return;
 724     if (__bound_delete_region(ptr) != 0)
 725         bound_error("freeing invalid region");
 726
 727     libc_free(ptr);
 728 }
 729
 730 void *__bound_realloc(void *ptr, size_t size, const void *caller)
 731 {
 732     void *ptr1;
 733     int old_size;
 734
 735     if (size == 0) {
 736         __bound_free(ptr, caller);
 737         return NULL;
 738     } else {
 739         ptr1 = __bound_malloc(size, caller);
 740         if (ptr == NULL || ptr1 == NULL)
 741             return ptr1;
 742         old_size = get_region_size(ptr);
 743         if (old_size == EMPTY_SIZE)
 744             bound_error("realloc'ing invalid pointer");
 745         memcpy(ptr1, ptr, old_size);
 746         __bound_free(ptr, caller);
 747         return ptr1;
 748     }
 749 }
 750
 751 #ifndef CONFIG_TCC_MALLOC_HOOKS
 752 void *__bound_calloc(size_t nmemb, size_t size)
 753 {
 754     void *ptr;
 755     size = size * nmemb;
 756     ptr = __bound_malloc(size, NULL);
 757     if (!ptr)
 758         return NULL;
 759     memset(ptr, 0, size);
 760     return ptr;
 761 }
 762 #endif
 763
 764 #if 0
 765 static void bound_dump(void)
 766 {
 767     BoundEntry *page, *e;
 768     int i, j;
 769
 770     printf("region dump:\n");
 771     for(i=0;i<BOUND_T1_SIZE;i++) {
 772         page = __bound_t1[i];
 773         for(j=0;j<BOUND_T2_SIZE;j++) {
 774             e = page + j;
 775             /* do not print invalid or empty entries */
 776             if (e->size != EMPTY_SIZE && e->start != 0) {
 777                 printf("%08x:",
 778                        (i << (BOUND_T2_BITS + BOUND_T3_BITS)) +
 779                        (j << BOUND_T3_BITS));
 780                 do {
 781                     printf(" %08lx:%08lx", e->start, e->start + e->size);
 782                     e = e->next;
 783                 } while (e != NULL);
 784                 printf("\n");
 785             }
 786         }
 787     }
 788 }
 789 #endif
 790
 791 /* some useful checked functions */
 792
 793 /* check that (p ... p + size - 1) lies inside 'p' region, if any */
 794 static void __bound_check(const void *p, size_t size)
 795 {
 796     if (size == 0)
 797         return;
 798     p = __bound_ptr_add((void *)p, size);
 799     if (p == INVALID_POINTER)
 800         bound_error("invalid pointer");
 801 }
 802
 803 void *__bound_memcpy(void *dst, const void *src, size_t size)
 804 {
 805     __bound_check(dst, size);
 806     __bound_check(src, size);
 807     /* check also region overlap */
 808     if (src >= dst && src < dst + size)
 809         bound_error("overlapping regions in memcpy()");
 810     return memcpy(dst, src, size);
 811 }
 812
 813 void *__bound_memmove(void *dst, const void *src, size_t size)
 814 {
 815     __bound_check(dst, size);
 816     __bound_check(src, size);
 817     return memmove(dst, src, size);
 818 }
 819
 820 void *__bound_memset(void *dst, int c, size_t size)
 821 {
 822     __bound_check(dst, size);
 823     return memset(dst, c, size);
 824 }
 825
 826 /* XXX: could be optimized */
 827 int __bound_strlen(const char *s)
 828 {
 829     const char *p;
 830     int len;
 831
 832     len = 0;
 833     for(;;) {
 834         p = __bound_ptr_indir1((char *)s, len);
 835         if (p == INVALID_POINTER)
 836             bound_error("bad pointer in strlen()");
 837         if (*p == '\0')
 838             break;
 839         len++;
 840     }
 841     return len;
 842 }
 843
 844 char *__bound_strcpy(char *dst, const char *src)
 845 {
 846     int len;
 847     len = __bound_strlen(src);
 848     return __bound_memcpy(dst, src, len + 1);
 849 }
 850