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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 | /* * Buffer-based memory allocator * * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * This file is part of mbed TLS (https://tls.mbed.org) */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C) #include "mbedtls/memory_buffer_alloc.h" /* No need for the header guard as MBEDTLS_MEMORY_BUFFER_ALLOC_C is dependent upon MBEDTLS_PLATFORM_C */ #include "mbedtls/platform.h" #include "mbedtls/platform_util.h" #include <string.h> #if defined(MBEDTLS_MEMORY_BACKTRACE) #include <execinfo.h> #endif #if defined(MBEDTLS_THREADING_C) #include "mbedtls/threading.h" #endif #define MAGIC1 0xFF00AA55 #define MAGIC2 0xEE119966 #define MAX_BT 20 typedef struct _memory_header memory_header; struct _memory_header { size_t magic1; size_t size; size_t alloc; memory_header *prev; memory_header *next; memory_header *prev_free; memory_header *next_free; #if defined(MBEDTLS_MEMORY_BACKTRACE) char **trace; size_t trace_count; #endif size_t magic2; }; typedef struct { unsigned char *buf; size_t len; memory_header *first; memory_header *first_free; int verify; #if defined(MBEDTLS_MEMORY_DEBUG) size_t alloc_count; size_t free_count; size_t total_used; size_t maximum_used; size_t header_count; size_t maximum_header_count; #endif #if defined(MBEDTLS_THREADING_C) mbedtls_threading_mutex_t mutex; #endif } buffer_alloc_ctx; static buffer_alloc_ctx heap; #if defined(MBEDTLS_MEMORY_DEBUG) static void debug_header( memory_header *hdr ) { #if defined(MBEDTLS_MEMORY_BACKTRACE) size_t i; #endif mbedtls_fprintf( stderr, "HDR: PTR(%10zu), PREV(%10zu), NEXT(%10zu), " "ALLOC(%zu), SIZE(%10zu)\n", (size_t) hdr, (size_t) hdr->prev, (size_t) hdr->next, hdr->alloc, hdr->size ); mbedtls_fprintf( stderr, " FPREV(%10zu), FNEXT(%10zu)\n", (size_t) hdr->prev_free, (size_t) hdr->next_free ); #if defined(MBEDTLS_MEMORY_BACKTRACE) mbedtls_fprintf( stderr, "TRACE: \n" ); for( i = 0; i < hdr->trace_count; i++ ) mbedtls_fprintf( stderr, "%s\n", hdr->trace[i] ); mbedtls_fprintf( stderr, "\n" ); #endif } static void debug_chain( void ) { memory_header *cur = heap.first; mbedtls_fprintf( stderr, "\nBlock list\n" ); while( cur != NULL ) { debug_header( cur ); cur = cur->next; } mbedtls_fprintf( stderr, "Free list\n" ); cur = heap.first_free; while( cur != NULL ) { debug_header( cur ); cur = cur->next_free; } } #endif /* MBEDTLS_MEMORY_DEBUG */ static int verify_header( memory_header *hdr ) { if( hdr->magic1 != MAGIC1 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: MAGIC1 mismatch\n" ); #endif return( 1 ); } if( hdr->magic2 != MAGIC2 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: MAGIC2 mismatch\n" ); #endif return( 1 ); } if( hdr->alloc > 1 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: alloc has illegal value\n" ); #endif return( 1 ); } if( hdr->prev != NULL && hdr->prev == hdr->next ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: prev == next\n" ); #endif return( 1 ); } if( hdr->prev_free != NULL && hdr->prev_free == hdr->next_free ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: prev_free == next_free\n" ); #endif return( 1 ); } return( 0 ); } static int verify_chain( void ) { memory_header *prv = heap.first, *cur; if( prv == NULL || verify_header( prv ) != 0 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: verification of first header " "failed\n" ); #endif return( 1 ); } if( heap.first->prev != NULL ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: verification failed: " "first->prev != NULL\n" ); #endif return( 1 ); } cur = heap.first->next; while( cur != NULL ) { if( verify_header( cur ) != 0 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: verification of header " "failed\n" ); #endif return( 1 ); } if( cur->prev != prv ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: verification failed: " "cur->prev != prv\n" ); #endif return( 1 ); } prv = cur; cur = cur->next; } return( 0 ); } static void *buffer_alloc_calloc( size_t n, size_t size ) { memory_header *new, *cur = heap.first_free; unsigned char *p; void *ret; size_t original_len, len; #if defined(MBEDTLS_MEMORY_BACKTRACE) void *trace_buffer[MAX_BT]; size_t trace_cnt; #endif if( heap.buf == NULL || heap.first == NULL ) return( NULL ); original_len = len = n * size; if( n == 0 || size == 0 || len / n != size ) return( NULL ); else if( len > (size_t)-MBEDTLS_MEMORY_ALIGN_MULTIPLE ) return( NULL ); if( len % MBEDTLS_MEMORY_ALIGN_MULTIPLE ) { len -= len % MBEDTLS_MEMORY_ALIGN_MULTIPLE; len += MBEDTLS_MEMORY_ALIGN_MULTIPLE; } // Find block that fits // while( cur != NULL ) { if( cur->size >= len ) break; cur = cur->next_free; } if( cur == NULL ) return( NULL ); if( cur->alloc != 0 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: block in free_list but allocated " "data\n" ); #endif mbedtls_exit( 1 ); } #if defined(MBEDTLS_MEMORY_DEBUG) heap.alloc_count++; #endif // Found location, split block if > memory_header + 4 room left // if( cur->size - len < sizeof(memory_header) + MBEDTLS_MEMORY_ALIGN_MULTIPLE ) { cur->alloc = 1; // Remove from free_list // if( cur->prev_free != NULL ) cur->prev_free->next_free = cur->next_free; else heap.first_free = cur->next_free; if( cur->next_free != NULL ) cur->next_free->prev_free = cur->prev_free; cur->prev_free = NULL; cur->next_free = NULL; #if defined(MBEDTLS_MEMORY_DEBUG) heap.total_used += cur->size; if( heap.total_used > heap.maximum_used ) heap.maximum_used = heap.total_used; #endif #if defined(MBEDTLS_MEMORY_BACKTRACE) trace_cnt = backtrace( trace_buffer, MAX_BT ); cur->trace = backtrace_symbols( trace_buffer, trace_cnt ); cur->trace_count = trace_cnt; #endif if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 ) mbedtls_exit( 1 ); ret = (unsigned char *) cur + sizeof( memory_header ); memset( ret, 0, original_len ); return( ret ); } p = ( (unsigned char *) cur ) + sizeof(memory_header) + len; new = (memory_header *) p; new->size = cur->size - len - sizeof(memory_header); new->alloc = 0; new->prev = cur; new->next = cur->next; #if defined(MBEDTLS_MEMORY_BACKTRACE) new->trace = NULL; new->trace_count = 0; #endif new->magic1 = MAGIC1; new->magic2 = MAGIC2; if( new->next != NULL ) new->next->prev = new; // Replace cur with new in free_list // new->prev_free = cur->prev_free; new->next_free = cur->next_free; if( new->prev_free != NULL ) new->prev_free->next_free = new; else heap.first_free = new; if( new->next_free != NULL ) new->next_free->prev_free = new; cur->alloc = 1; cur->size = len; cur->next = new; cur->prev_free = NULL; cur->next_free = NULL; #if defined(MBEDTLS_MEMORY_DEBUG) heap.header_count++; if( heap.header_count > heap.maximum_header_count ) heap.maximum_header_count = heap.header_count; heap.total_used += cur->size; if( heap.total_used > heap.maximum_used ) heap.maximum_used = heap.total_used; #endif #if defined(MBEDTLS_MEMORY_BACKTRACE) trace_cnt = backtrace( trace_buffer, MAX_BT ); cur->trace = backtrace_symbols( trace_buffer, trace_cnt ); cur->trace_count = trace_cnt; #endif if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 ) mbedtls_exit( 1 ); ret = (unsigned char *) cur + sizeof( memory_header ); memset( ret, 0, original_len ); return( ret ); } static void buffer_alloc_free( void *ptr ) { memory_header *hdr, *old = NULL; unsigned char *p = (unsigned char *) ptr; if( ptr == NULL || heap.buf == NULL || heap.first == NULL ) return; if( p < heap.buf || p >= heap.buf + heap.len ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: mbedtls_free() outside of managed " "space\n" ); #endif mbedtls_exit( 1 ); } p -= sizeof(memory_header); hdr = (memory_header *) p; if( verify_header( hdr ) != 0 ) mbedtls_exit( 1 ); if( hdr->alloc != 1 ) { #if defined(MBEDTLS_MEMORY_DEBUG) mbedtls_fprintf( stderr, "FATAL: mbedtls_free() on unallocated " "data\n" ); #endif mbedtls_exit( 1 ); } hdr->alloc = 0; #if defined(MBEDTLS_MEMORY_DEBUG) heap.free_count++; heap.total_used -= hdr->size; #endif #if defined(MBEDTLS_MEMORY_BACKTRACE) free( hdr->trace ); hdr->trace = NULL; hdr->trace_count = 0; #endif // Regroup with block before // if( hdr->prev != NULL && hdr->prev->alloc == 0 ) { #if defined(MBEDTLS_MEMORY_DEBUG) heap.header_count--; #endif hdr->prev->size += sizeof(memory_header) + hdr->size; hdr->prev->next = hdr->next; old = hdr; hdr = hdr->prev; if( hdr->next != NULL ) hdr->next->prev = hdr; memset( old, 0, sizeof(memory_header) ); } // Regroup with block after // if( hdr->next != NULL && hdr->next->alloc == 0 ) { #if defined(MBEDTLS_MEMORY_DEBUG) heap.header_count--; #endif hdr->size += sizeof(memory_header) + hdr->next->size; old = hdr->next; hdr->next = hdr->next->next; if( hdr->prev_free != NULL || hdr->next_free != NULL ) { if( hdr->prev_free != NULL ) hdr->prev_free->next_free = hdr->next_free; else heap.first_free = hdr->next_free; if( hdr->next_free != NULL ) hdr->next_free->prev_free = hdr->prev_free; } hdr->prev_free = old->prev_free; hdr->next_free = old->next_free; if( hdr->prev_free != NULL ) hdr->prev_free->next_free = hdr; else heap.first_free = hdr; if( hdr->next_free != NULL ) hdr->next_free->prev_free = hdr; if( hdr->next != NULL ) hdr->next->prev = hdr; memset( old, 0, sizeof(memory_header) ); } // Prepend to free_list if we have not merged // (Does not have to stay in same order as prev / next list) // if( old == NULL ) { hdr->next_free = heap.first_free; if( heap.first_free != NULL ) heap.first_free->prev_free = hdr; heap.first_free = hdr; } if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_FREE ) && verify_chain() != 0 ) mbedtls_exit( 1 ); } void mbedtls_memory_buffer_set_verify( int verify ) { heap.verify = verify; } int mbedtls_memory_buffer_alloc_verify( void ) { return verify_chain(); } #if defined(MBEDTLS_MEMORY_DEBUG) void mbedtls_memory_buffer_alloc_status( void ) { mbedtls_fprintf( stderr, "Current use: %zu blocks / %zu bytes, max: %zu blocks / " "%zu bytes (total %zu bytes), alloc / free: %zu / %zu\n", heap.header_count, heap.total_used, heap.maximum_header_count, heap.maximum_used, heap.maximum_header_count * sizeof( memory_header ) + heap.maximum_used, heap.alloc_count, heap.free_count ); if( heap.first->next == NULL ) { mbedtls_fprintf( stderr, "All memory de-allocated in stack buffer\n" ); } else { mbedtls_fprintf( stderr, "Memory currently allocated:\n" ); debug_chain(); } } void mbedtls_memory_buffer_alloc_max_get( size_t *max_used, size_t *max_blocks ) { *max_used = heap.maximum_used; *max_blocks = heap.maximum_header_count; } void mbedtls_memory_buffer_alloc_max_reset( void ) { heap.maximum_used = 0; heap.maximum_header_count = 0; } void mbedtls_memory_buffer_alloc_cur_get( size_t *cur_used, size_t *cur_blocks ) { *cur_used = heap.total_used; *cur_blocks = heap.header_count; } #endif /* MBEDTLS_MEMORY_DEBUG */ #if defined(MBEDTLS_THREADING_C) static void *buffer_alloc_calloc_mutexed( size_t n, size_t size ) { void *buf; if( mbedtls_mutex_lock( &heap.mutex ) != 0 ) return( NULL ); buf = buffer_alloc_calloc( n, size ); if( mbedtls_mutex_unlock( &heap.mutex ) ) return( NULL ); return( buf ); } static void buffer_alloc_free_mutexed( void *ptr ) { /* We have to good option here, but corrupting the heap seems * worse than loosing memory. */ if( mbedtls_mutex_lock( &heap.mutex ) ) return; buffer_alloc_free( ptr ); (void) mbedtls_mutex_unlock( &heap.mutex ); } #endif /* MBEDTLS_THREADING_C */ void mbedtls_memory_buffer_alloc_init( unsigned char *buf, size_t len ) { memset( &heap, 0, sizeof( buffer_alloc_ctx ) ); #if defined(MBEDTLS_THREADING_C) mbedtls_mutex_init( &heap.mutex ); mbedtls_platform_set_calloc_free( buffer_alloc_calloc_mutexed, buffer_alloc_free_mutexed ); #else mbedtls_platform_set_calloc_free( buffer_alloc_calloc, buffer_alloc_free ); #endif if( len < sizeof( memory_header ) + MBEDTLS_MEMORY_ALIGN_MULTIPLE ) return; else if( (size_t)buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE ) { /* Adjust len first since buf is used in the computation */ len -= MBEDTLS_MEMORY_ALIGN_MULTIPLE - (size_t)buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE; buf += MBEDTLS_MEMORY_ALIGN_MULTIPLE - (size_t)buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE; } memset( buf, 0, len ); heap.buf = buf; heap.len = len; heap.first = (memory_header *)buf; heap.first->size = len - sizeof( memory_header ); heap.first->magic1 = MAGIC1; heap.first->magic2 = MAGIC2; heap.first_free = heap.first; } void mbedtls_memory_buffer_alloc_free( void ) { #if defined(MBEDTLS_THREADING_C) mbedtls_mutex_free( &heap.mutex ); #endif mbedtls_platform_zeroize( &heap, sizeof(buffer_alloc_ctx) ); } #if defined(MBEDTLS_SELF_TEST) static int check_pointer( void *p ) { if( p == NULL ) return( -1 ); if( (size_t) p % MBEDTLS_MEMORY_ALIGN_MULTIPLE != 0 ) return( -1 ); return( 0 ); } static int check_all_free( void ) { if( #if defined(MBEDTLS_MEMORY_DEBUG) heap.total_used != 0 || #endif heap.first != heap.first_free || (void *) heap.first != (void *) heap.buf ) { return( -1 ); } return( 0 ); } #define TEST_ASSERT( condition ) \ if( ! (condition) ) \ { \ if( verbose != 0 ) \ mbedtls_printf( "failed\n" ); \ \ ret = 1; \ goto cleanup; \ } int mbedtls_memory_buffer_alloc_self_test( int verbose ) { unsigned char buf[1024]; unsigned char *p, *q, *r, *end; int ret = 0; if( verbose != 0 ) mbedtls_printf( " MBA test #1 (basic alloc-free cycle): " ); mbedtls_memory_buffer_alloc_init( buf, sizeof( buf ) ); p = mbedtls_calloc( 1, 1 ); q = mbedtls_calloc( 1, 128 ); r = mbedtls_calloc( 1, 16 ); TEST_ASSERT( check_pointer( p ) == 0 && check_pointer( q ) == 0 && check_pointer( r ) == 0 ); mbedtls_free( r ); mbedtls_free( q ); mbedtls_free( p ); TEST_ASSERT( check_all_free( ) == 0 ); /* Memorize end to compare with the next test */ end = heap.buf + heap.len; mbedtls_memory_buffer_alloc_free( ); if( verbose != 0 ) mbedtls_printf( "passed\n" ); if( verbose != 0 ) mbedtls_printf( " MBA test #2 (buf not aligned): " ); mbedtls_memory_buffer_alloc_init( buf + 1, sizeof( buf ) - 1 ); TEST_ASSERT( heap.buf + heap.len == end ); p = mbedtls_calloc( 1, 1 ); q = mbedtls_calloc( 1, 128 ); r = mbedtls_calloc( 1, 16 ); TEST_ASSERT( check_pointer( p ) == 0 && check_pointer( q ) == 0 && check_pointer( r ) == 0 ); mbedtls_free( r ); mbedtls_free( q ); mbedtls_free( p ); TEST_ASSERT( check_all_free( ) == 0 ); mbedtls_memory_buffer_alloc_free( ); if( verbose != 0 ) mbedtls_printf( "passed\n" ); if( verbose != 0 ) mbedtls_printf( " MBA test #3 (full): " ); mbedtls_memory_buffer_alloc_init( buf, sizeof( buf ) ); p = mbedtls_calloc( 1, sizeof( buf ) - sizeof( memory_header ) ); TEST_ASSERT( check_pointer( p ) == 0 ); TEST_ASSERT( mbedtls_calloc( 1, 1 ) == NULL ); mbedtls_free( p ); p = mbedtls_calloc( 1, sizeof( buf ) - 2 * sizeof( memory_header ) - 16 ); q = mbedtls_calloc( 1, 16 ); TEST_ASSERT( check_pointer( p ) == 0 && check_pointer( q ) == 0 ); TEST_ASSERT( mbedtls_calloc( 1, 1 ) == NULL ); mbedtls_free( q ); TEST_ASSERT( mbedtls_calloc( 1, 17 ) == NULL ); mbedtls_free( p ); TEST_ASSERT( check_all_free( ) == 0 ); mbedtls_memory_buffer_alloc_free( ); if( verbose != 0 ) mbedtls_printf( "passed\n" ); cleanup: mbedtls_memory_buffer_alloc_free( ); return( ret ); } #endif /* MBEDTLS_SELF_TEST */ #endif /* MBEDTLS_MEMORY_BUFFER_ALLOC_C */ |