KernelLand/Kernel/heap.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * heap.c
   6  * - Dynamic memory allocation
   7  */
   8 #include <acess.h>
   9 #include <mm_virt.h>
  10 #include <heap_int.h>
  11 #include <limits.h>
  12 #include <debug_hooks.h>
  13
  14 #define WARNINGS        1       // Warn and dump on heap errors
  15 #define DEBUG_TRACE     0       // Enable tracing of allocations
  16 #define VERBOSE_DUMP    0       // Set to 1 to enable a verbose dump when heap errors are encountered
  17 #define VALIDATE_ON_ALLOC       1       // Set to 1 to enable validation of the heap on all malloc() calls
  18
  19 // === CONSTANTS ===
  20 #define HEAP_INIT_SIZE  0x8000  // 32 KiB
  21 #define MIN_SIZE        (sizeof(void*))*8       // 8 Machine Words
  22 #define POW2_SIZES      0
  23 #define COMPACT_HEAP    0       // Use 4 byte header?
  24 #define FIRST_FIT       0
  25
  26 //#define       MAGIC_FOOT      0x2ACE5505
  27 //#define       MAGIC_FREE      0xACE55000
  28 //#define       MAGIC_USED      0x862B0505      // MAGIC_FOOT ^ MAGIC_FREE
  29 #define MAGIC_FOOT      0x544F4F46      // 'FOOT'
  30 #define MAGIC_FREE      0x45455246      // 'FREE'
  31 #define MAGIC_USED      0x44455355      // 'USED'
  32
  33 // === PROTOTYPES ===
  34 void    Heap_Install(void);
  35 void    *Heap_Extend(size_t Bytes);
  36 void    *Heap_Merge(tHeapHead *Head);
  37 static const size_t     Heap_int_GetBlockSize(size_t AllocSize);
  38 //void  *Heap_Allocate(const char *File, int Line, size_t Bytes);
  39 //void  *Heap_AllocateZero(const char *File, int Line, size_t Bytes);
  40 //void  *Heap_Reallocate(const char *File, int Line, void *Ptr, size_t Bytes);
  41 //void  Heap_Deallocate(const char *File, int Line, void *Ptr);
  42  int    Heap_int_ApplyWatchpont(void *Addr, bool Enabled);
  43 void    Heap_int_WatchBlock(tHeapHead *Head, bool Enabled);
  44 //void  Heap_Dump(void);
  45 void    Heap_ValidateDump(int bVerbose);
  46 //void  Heap_Stats(void);
  47
  48 // === GLOBALS ===
  49 tMutex  glHeap;
  50 tHeapHead       *gHeapStart;
  51 tHeapHead       *gHeapEnd;
  52
  53 // === CODE ===
  54 void Heap_Install(void)
  55 {
  56         gHeapStart = (void*)MM_KHEAP_BASE;
  57         gHeapEnd   = gHeapStart;
  58         Heap_Extend(HEAP_INIT_SIZE);
  59 }
  60
  61 static inline tHeapHead *Heap_NextHead(tHeapHead *Head) {
  62         return (void*)( (char*)Head + Head->Size );
  63 }
  64 static inline tHeapFoot *Heap_ThisFoot(tHeapHead *Head) {
  65         return (void*)( (char*)Head + Head->Size - sizeof(tHeapFoot) );
  66 }
  67 static inline tHeapFoot *Heap_PrevFoot(tHeapHead *Head) {
  68         //ASSERT(Head != gHeapStart);
  69         return (void*)( (char*)Head - sizeof(tHeapFoot) );
  70 }
  71
  72 /**
  73  * \brief Extend the size of the heap
  74  */
  75 void *Heap_Extend(size_t Bytes)
  76 {
  77         //Debug("Heap_Extend(0x%x)", Bytes);
  78
  79         // Bounds Check
  80         if( gHeapEnd == (tHeapHead*)MM_KHEAP_MAX ) {
  81                 Log_Error("Heap", "Heap limit reached (%p)", (void*)MM_KHEAP_MAX);
  82                 return NULL;
  83         }
  84
  85         if( Bytes == 0 ) {
  86                 Log_Warning("Heap", "Heap_Extend called with Bytes=%i", Bytes);
  87                 return NULL;
  88         }
  89
  90         const Uint      pages = (Bytes + 0xFFF) >> 12;
  91         tHeapHead       *new_end = (void*)( (tVAddr)gHeapEnd + (pages << 12) );
  92         // Bounds Check
  93         if( new_end > (tHeapHead*)MM_KHEAP_MAX )
  94         {
  95                 Log_Error("Heap", "Heap limit exceeded (%p)", (void*)new_end);
  96                 // TODO: Clip allocation to available space, and have caller check returned block
  97                 return NULL;
  98         }
  99
 100         // Heap expands in pages
 101         for( Uint i = 0; i < pages; i ++ )
 102         {
 103                 if( !MM_Allocate( (tPage*)gHeapEnd + i ) )
 104                 {
 105                         Warning("OOM - Heap_Extend (%i bytes)");
 106                         Heap_Dump();
 107                         return NULL;
 108                 }
 109         }
 110
 111         // Increase heap end
 112         tHeapHead       *head = gHeapEnd;
 113         gHeapEnd = new_end;
 114
 115         // Create Block
 116         head->Size = (Bytes+0xFFF)&~0xFFF;
 117         head->Magic = MAGIC_FREE;
 118         tHeapFoot *foot = Heap_ThisFoot(head);
 119         foot->Head = head;
 120         foot->Magic = MAGIC_FOOT;
 121
 122         return Heap_Merge(head);        // Merge with previous block
 123 }
 124
 125 /**
 126  * \brief Merges two adjacent heap blocks
 127  */
 128 void *Heap_Merge(tHeapHead *Head)
 129 {
 130         //Log("Heap_Merge: (Head=%p)", Head);
 131         tHeapFoot *thisFoot = Heap_ThisFoot(Head);
 132
 133         ASSERT( Heap_NextHead(Head) <= gHeapEnd );
 134
 135         // Merge Left (Down)
 136         tHeapFoot *foot = Heap_PrevFoot(Head);
 137         if( Head > gHeapStart && foot->Head->Magic == MAGIC_FREE)
 138         {
 139                 foot->Head->Size += Head->Size; // Increase size
 140                 thisFoot->Head = foot->Head;    // Change backlink
 141                 Head->Magic = 0;        // Clear old head
 142                 Head->Size = 0;
 143                 Head = foot->Head;      // Save new head address
 144                 foot->Head = NULL;      // Clear central footer
 145                 foot->Magic = 0;
 146         }
 147
 148         // Merge Right (Upwards)
 149         tHeapHead *nexthead = Heap_NextHead(Head);
 150         if(nexthead < gHeapEnd && nexthead->Magic == MAGIC_FREE)
 151         {
 152                 Head->Size += nexthead->Size;
 153                 foot = Heap_ThisFoot(Head);
 154                 foot->Head = Head;      // Update Backlink
 155                 thisFoot->Head = NULL;  // Clear old footer
 156                 thisFoot->Magic = 0;
 157                 nexthead->Size = 0;             // Clear old header
 158                 nexthead->Magic = 0;
 159         }
 160
 161         // Return new address
 162         return Head;
 163 }
 164
 165 static const size_t Heap_int_GetBlockSize(size_t AllocSize)
 166 {
 167         size_t Bytes;
 168         #if POW2_SIZES
 169         Bytes = AllocSize + sizeof(tHeapHead) + sizeof(tHeapFoot);
 170         Bytes = 1UUL << LOG2(Bytes);
 171         #else
 172         Bytes = (AllocSize + sizeof(tHeapHead) + sizeof(tHeapFoot) + MIN_SIZE-1) & ~(MIN_SIZE-1);
 173         #endif
 174         return Bytes;
 175 }
 176
 177 /**
 178  * \param File  Allocating source file
 179  * \param Line  Source line
 180  * \param __Bytes       Size of region to allocate
 181  */
 182 void *Heap_Allocate(const char *File, int Line, size_t __Bytes)
 183 {
 184         tHeapHead       *newhead;
 185         tHeapFoot       *foot, *newfoot;
 186         tHeapHead       *best = NULL;
 187         Uint    bestSize = UINT_MAX;    // Speed hack
 188         size_t  Bytes;
 189
 190         if( __Bytes == 0 ) {
 191                 return NULL;    // TODO: Return a known un-mapped range.
 192 //              return INVLPTR;
 193         }
 194
 195         #if VALIDATE_ON_ALLOC
 196         Heap_Validate();
 197         #endif
 198
 199         // Get required size
 200         Bytes = Heap_int_GetBlockSize(__Bytes);
 201
 202         // Lock Heap
 203         Mutex_Acquire(&glHeap);
 204
 205         // Traverse Heap
 206         for( tHeapHead *head = gHeapStart; head < gHeapEnd; head = Heap_NextHead(head) )
 207         {
 208                 // Alignment Check
 209                 #if POW2_SIZES
 210                 if( head->Size != 1UUL << LOG2(head->Size) ) {
 211                 #else
 212                 if( head->Size & (MIN_SIZE-1) ) {
 213                 #endif
 214                         Mutex_Release(&glHeap); // Release spinlock
 215                         #if WARNINGS
 216                         Log_Warning("Heap", "Size of heap address %p is invalid"
 217                                 " - not aligned (0x%x) [at paddr 0x%x]",
 218                                 head, head->Size, MM_GetPhysAddr(&head->Size));
 219                         Heap_ValidateDump(VERBOSE_DUMP);
 220                         #endif
 221                         return NULL;
 222                 }
 223                 if( head->Size < MIN_SIZE ) {
 224                         Mutex_Release(&glHeap);
 225                         #if WARNINGS
 226                         Log_Warning("Heap", "Size of heap address %p is invalid"
 227                                 " - Too small (0x%x) [at paddr 0x%x]",
 228                                 head, head->Size, MM_GetPhysAddr(&head->Size));
 229                         Heap_ValidateDump(VERBOSE_DUMP);
 230                         #endif
 231                         return NULL;
 232                 }
 233                 if( head->Size > (2<<30) ) {
 234                         Mutex_Release(&glHeap);
 235                         #if WARNINGS
 236                         Log_Warning("Heap", "Size of heap address %p is invalid"
 237                                 " - Over 2GiB (0x%x) [at paddr 0x%x]",
 238                                 head, head->Size, MM_GetPhysAddr(&head->Size));
 239                         Heap_ValidateDump(VERBOSE_DUMP);
 240                         #endif
 241                         return NULL;
 242                 }
 243
 244                 // Check if allocated
 245                 if(head->Magic == MAGIC_USED)   continue;
 246                 // Error check
 247                 if(head->Magic != MAGIC_FREE)   {
 248                         Mutex_Release(&glHeap); // Release spinlock
 249                         #if WARNINGS
 250                         Log_Warning("Heap", "Magic of heap address %p is invalid (%p = 0x%x)",
 251                                 head, &head->Magic, head->Magic);
 252                         Heap_ValidateDump(VERBOSE_DUMP);
 253                         #endif
 254                         return NULL;
 255                 }
 256
 257                 // Size check
 258                 if(head->Size < Bytes)  continue;
 259
 260                 // Perfect fit
 261                 if(head->Size == Bytes) {
 262                         head->Magic = MAGIC_USED;
 263                         head->File = File;
 264                         head->Line = Line;
 265                         head->ValidSize = __Bytes;
 266                         head->AllocateTime = now();
 267                         Mutex_Release(&glHeap); // Release spinlock
 268                         #if DEBUG_TRACE
 269                         Log_Debug("Heap", "Malloc'd %p (0x%x bytes), returning to %s:%i",
 270                                 head->Data, head->Size, File, Line);
 271                         #endif
 272                         return head->Data;
 273                 }
 274
 275                 // Break out of loop
 276                 #if FIRST_FIT
 277                 best = head;
 278                 bestSize = head->Size;
 279                 break;
 280                 #else
 281                 // or check if the block is the best size
 282                 if(bestSize > head->Size) {
 283                         best = head;
 284                         bestSize = head->Size;
 285                 }
 286                 #endif
 287         }
 288
 289         // If no block large enough is found, create one
 290         if(!best)
 291         {
 292                 best = Heap_Extend( Bytes );
 293                 // Check for errors
 294                 if(!best) {
 295                         Warning("OOM when allocating 0x%x bytes", Bytes);
 296                         Mutex_Release(&glHeap); // Release spinlock
 297                         return NULL;
 298                 }
 299                 // Check size
 300                 if(best->Size == Bytes) {
 301                         best->Magic = MAGIC_USED;       // Mark block as used
 302                         best->File = File;
 303                         best->Line = Line;
 304                         best->ValidSize = __Bytes;
 305                         best->AllocateTime = now();
 306                         Mutex_Release(&glHeap); // Release spinlock
 307                         #if DEBUG_TRACE
 308                         Log_Debug("Heap", "Malloc'd %p (0x%x bytes), returning to %s:%i",
 309                                 best->Data, best->Size, File, Line);
 310                         #endif
 311                         return best->Data;
 312                 }
 313         }
 314
 315         // Split Block
 316         // - Save size for new block
 317         size_t  newsize = best->Size - Bytes;
 318         // - Allocate beginning of old block
 319         best->Size = Bytes;             // Update size in old header
 320         best->ValidSize = __Bytes;
 321         best->Magic = MAGIC_USED;       // Mark block as used
 322         best->File = File;
 323         best->Line = Line;
 324         best->AllocateTime = now();
 325         // - Create a new foot on old block
 326         newfoot = Heap_ThisFoot(best);
 327         newfoot->Head = best;   // Create new footer
 328         newfoot->Magic = MAGIC_FOOT;
 329         // - Create a new header after resized old
 330         newhead = Heap_NextHead(best);
 331         newhead->Size = newsize;
 332         newhead->Magic = MAGIC_FREE;
 333         newhead->ValidSize = 0;
 334         newhead->File = NULL;
 335         newhead->Line = 0;
 336         // - Update footer
 337         foot = Heap_ThisFoot(newhead);
 338         foot->Head = newhead;
 339
 340         Mutex_Release(&glHeap); // Release spinlock
 341         #if DEBUG_TRACE
 342         Log_Debug("Heap", "Malloc'd %p (0x%x bytes), returning to %s:%i",
 343                 best->Data, best->Size, File, Line);
 344         #endif
 345         return best->Data;
 346 }
 347
 348 /**
 349  * \brief Free an allocated memory block
 350  */
 351 void Heap_Deallocate(const char *File, int Line, void *Ptr)
 352 {
 353         // INVLPTR is returned from Heap_Allocate when the allocation
 354         // size is zero.
 355         if( Ptr == INVLPTR )    return;
 356
 357         // Alignment Check
 358         if( (tVAddr)Ptr % sizeof(void*) != 0 ) {
 359                 Log_Warning("Heap", "free - Passed a non-aligned address (%p)", Ptr);
 360                 return;
 361         }
 362
 363         // Sanity check
 364         if((Uint)Ptr < (Uint)gHeapStart || (Uint)Ptr > (Uint)gHeapEnd)
 365         {
 366                 Log_Warning("Heap", "free - Passed a non-heap address by %p (%p < %p < %p)",
 367                         __builtin_return_address(0), gHeapStart, Ptr, gHeapEnd);
 368                 return;
 369         }
 370
 371         // Check memory block - Header
 372         tHeapHead *head = (tHeapHead*)Ptr - 1;
 373         if(head->Magic == MAGIC_FREE) {
 374                 Log_Warning("Heap", "free - Passed a freed block (%p) by %s:%i (was freed by %s:%i)",
 375                         head, File, Line,
 376                         head->File, head->Line);
 377                 Proc_PrintBacktrace();
 378                 return;
 379         }
 380         if(head->Magic != MAGIC_USED) {
 381                 Log_Warning("Heap", "free - Magic value is invalid (%p, 0x%x)", head, head->Magic);
 382                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 383                 return;
 384         }
 385
 386         // Check memory block - Footer
 387         tHeapFoot *foot = Heap_ThisFoot(head);
 388         if(foot->Head != head) {
 389                 Log_Warning("Heap", "free - Footer backlink is incorrect (%p, 0x%x)", head, foot->Head);
 390                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 391                 return;
 392         }
 393         if(foot->Magic != MAGIC_FOOT) {
 394                 Log_Warning("Heap", "free - Footer magic is invalid (%p, %p = 0x%x)",
 395                         head, &foot->Magic, foot->Magic);
 396                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 397                 return;
 398         }
 399
 400         #if DEBUG_TRACE
 401         Log_Debug("Heap", "free: %p freed by %s:%i (%i old)",
 402                 Ptr, File, Line, now()-head->AllocateTime);
 403         #endif
 404
 405         // Lock
 406         Mutex_Acquire( &glHeap );
 407
 408         Heap_int_WatchBlock(head, false);
 409
 410         // Mark as free
 411         head->Magic = MAGIC_FREE;
 412         head->File = File;
 413         head->Line = Line;
 414         head->ValidSize = 0;
 415         // Merge blocks
 416         Heap_Merge( head );
 417
 418         // Release
 419         Mutex_Release( &glHeap );
 420 }
 421
 422 /**
 423  * \brief Increase/Decrease the size of an allocation
 424  * \param File  Calling File
 425  * \param Line  Calling Line
 426  * \param __ptr Old memory
 427  * \param __size        New Size
 428  */
 429 void *Heap_Reallocate(const char *File, int Line, void *__ptr, size_t __size)
 430 {
 431         tHeapHead       *head = (tHeapHead*)__ptr - 1;
 432         tHeapHead       *nextHead;
 433         tHeapFoot       *foot;
 434         Uint    newSize = Heap_int_GetBlockSize(__size);
 435
 436         // Check for reallocating NULL
 437         if(__ptr == NULL)
 438                 return Heap_Allocate(File, Line, __size);
 439
 440         if( !Heap_IsHeapAddr(__ptr)) {
 441                 Log_Error("Heap", "%s:%i passed non-heap address %p when reallocating to %zi",
 442                         File, Line, __ptr, __size);
 443                 return NULL;
 444         }
 445
 446         // Check if resize is needed
 447         // TODO: Reduce size of block if needed
 448         if(newSize <= head->Size) {
 449                 #if DEBUG_TRACE
 450                 Log_Debug("Heap", "realloc maintain %p (0x%x >= 0x%x), returning to %s:%i",
 451                         head->Data, head->Size, newSize, File, Line);
 452                 #endif
 453                 return __ptr;
 454         }
 455
 456         #if VALIDATE_ON_ALLOC
 457         Heap_Validate();
 458         #endif
 459
 460         Heap_int_WatchBlock(head, false);
 461
 462         // Check if next block is free
 463         nextHead = Heap_NextHead(head);
 464
 465         // Extend into next block
 466         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 467         {
 468                 #if DEBUG_TRACE
 469                 Log_Debug("Heap", "realloc expand %p (0x%x to 0x%x), returning to %s:%i",
 470                         head->Data, head->Size, newSize, File, Line);
 471                 #endif
 472                 Uint    size = nextHead->Size + head->Size;
 473                 foot = Heap_ThisFoot(nextHead);
 474                 // Exact Fit
 475                 if(size == newSize) {
 476                         head->Size = newSize;
 477                         head->ValidSize = __size;
 478                         head->File = File;
 479                         head->Line = Line;
 480                         foot->Head = head;
 481                         nextHead->Magic = 0;
 482                         nextHead->Size = 0;
 483                         return __ptr;
 484                 }
 485                 // Create a new heap block
 486                 // - Update old with new information
 487                 head->Size = newSize;
 488                 head->File = File;      // Kinda counts as a new allocation
 489                 head->Line = Line;
 490                 head->ValidSize = __size;
 491                 // - Create new footer
 492                 foot = Heap_ThisFoot(head);
 493                 foot->Head = head;
 494                 foot->Magic = MAGIC_FOOT;
 495                 // - Create new header
 496                 nextHead = Heap_NextHead(head);
 497                 nextHead->Size = size - newSize;
 498                 nextHead->Magic = MAGIC_FREE;
 499                 // - Update old footer
 500                 Heap_ThisFoot(nextHead)->Head = nextHead;
 501                 return __ptr;
 502         }
 503
 504         // Extend downwards?
 505         foot = Heap_PrevFoot(head);
 506         nextHead = foot->Head;
 507         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 508         {
 509                 Uint    size = nextHead->Size + head->Size;
 510                 // Inexact fit, split things up
 511                 if(size > newSize)
 512                 {
 513                         // TODO: Handle splitting of downwards blocks
 514                         Warning("[Heap   ] TODO: Space efficient realloc when new size is smaller");
 515                 }
 516
 517                 #if DEBUG_TRACE
 518                 Log_Debug("Heap", "realloc expand down %p (0x%x to 0x%x), returning to %s:%i",
 519                         head->Data, head->Size, newSize, File, Line);
 520                 #endif
 521
 522                 // Exact fit
 523                 Uint    oldDataSize;
 524                 // Set 1st (new/lower) header
 525                 nextHead->Magic = MAGIC_USED;
 526                 nextHead->Size = newSize;
 527                 nextHead->File = File;
 528                 nextHead->Line = Line;
 529                 nextHead->ValidSize = __size;
 530                 // Get 2nd (old) footer
 531                 foot = Heap_ThisFoot(nextHead);
 532                 foot->Head = nextHead;
 533                 // Save old data size
 534                 oldDataSize = head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead);
 535                 // Clear old header
 536                 head->Size = 0;
 537                 head->Magic = 0;
 538                 // Copy data
 539                 memmove(nextHead->Data, __ptr, oldDataSize);
 540                 // Return
 541                 return nextHead->Data;
 542         }
 543
 544         // Well, darn
 545         nextHead = Heap_Allocate( File, Line, __size );
 546         if(!nextHead)   return NULL;
 547         nextHead -= 1;
 548         nextHead->File = File;
 549         nextHead->Line = Line;
 550         nextHead->ValidSize = __size;
 551
 552         ASSERTC(head->Size, <, nextHead->Size);
 553         ASSERTC(__ptr, ==, head->Data);
 554         memcpy(
 555                 nextHead->Data,
 556                 __ptr,
 557                 head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead)
 558                 );
 559
 560         free(__ptr);
 561         Heap_Validate();
 562
 563         return nextHead->Data;
 564 }
 565
 566 /**
 567  * \fn void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 568  * \brief Allocate and Zero a buffer in memory
 569  * \param File  Allocating file
 570  * \param Line  Line of allocation
 571  * \param Bytes Size of the allocation
 572  */
 573 void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 574 {
 575         void    *ret = Heap_Allocate(File, Line, Bytes);
 576         if(ret == NULL) return NULL;
 577
 578         memset( ret, 0, Bytes );
 579
 580         return ret;
 581 }
 582
 583 /**
 584  * \fn int Heap_IsHeapAddr(void *Ptr)
 585  * \brief Checks if an address is a heap pointer
 586  */
 587 int Heap_IsHeapAddr(void *Ptr)
 588 {
 589         tHeapHead       *head;
 590         if((Uint)Ptr < (Uint)gHeapStart)        return 0;
 591         if((Uint)Ptr > (Uint)gHeapEnd)  return 0;
 592         if((Uint)Ptr & (sizeof(Uint)-1))        return 0;
 593
 594         head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 595         if(head->Magic != MAGIC_USED && head->Magic != MAGIC_FREE)
 596                 return 0;
 597
 598         return 1;
 599 }
 600
 601 int Heap_int_ApplyWatchpont(void *Word, bool enabled)
 602 {
 603         #if ARCHDIR_IS_x86
 604         static void     *active_wps[4];
 605         unsigned int    dr;
 606         for( dr = 2; dr < 4; dr ++ )
 607         {
 608                 if( (enabled && active_wps[dr] == NULL) || active_wps[dr] == Word)
 609                         break;
 610         }
 611         if(dr == 4) {
 612                 return 1;
 613         }
 614         if( enabled )
 615         {
 616                 active_wps[dr] = Word;
 617                 switch(dr)
 618                 {
 619                 //case 0:       ASM("mov %0, %%dr0" : : "r" (Word));    break;
 620                 //case 1:       ASM("mov %0, %%dr1" : : "r" (Word));    break;
 621                 case 2: ASM("mov %0, %%dr2" : : "r" (Word));    break;
 622                 case 3: ASM("mov %0, %%dr3" : : "r" (Word));    break;
 623                 default:        ASSERTC(dr,<,4);        return 1;
 624                 }
 625         }
 626         else
 627         {
 628                 active_wps[dr] = NULL;
 629         }
 630         Uint32  dr7flag;
 631         ASM("MOV %%dr7, %0" : "=r" (dr7flag));
 632         dr7flag &= ~(0x2 << (dr*2));
 633         dr7flag &= ~(0xF000 << (dr*4));
 634         if( enabled ) {
 635                 dr7flag |= 0x2 << (dr*2);
 636                 dr7flag |= 0xD000 << (dr*4);    // 4 bytes, write
 637                 Debug("Heap_int_ApplyWatchpont: Watchpoint #%i %p ENABLED", dr, Word);
 638         }
 639         else {
 640                 Debug("Heap_int_ApplyWatchpont: Watchpoint #%i %p disabled", dr, Word);
 641         }
 642         ASM("MOV %0, %%dr7" : : "r" (dr7flag));
 643         return 0;
 644         #else
 645         return 1;
 646         #endif
 647 }
 648
 649 void Heap_int_WatchBlock(tHeapHead *Head, bool Enabled)
 650 {
 651         int rv;
 652         rv = Heap_int_ApplyWatchpont( &Head->Size, Enabled );
 653         //rv = Heap_int_ApplyWatchpont( &Head->Magic, Enabled );
 654         rv = rv + Heap_int_ApplyWatchpont( &Heap_ThisFoot(Head)->Head, Enabled );
 655         if(rv && Enabled) {
 656                 Warning("Can't apply watch on %p", Head);
 657         }
 658 }
 659
 660 int Heap_WatchBlock(void *Ptr)
 661 {
 662         //Heap_int_ApplyWatchpont();
 663         tHeapHead       *head;
 664         if((Uint)Ptr < (Uint)gHeapStart)        return 0;
 665         if((Uint)Ptr > (Uint)gHeapEnd)  return 0;
 666         if((Uint)Ptr & (sizeof(Uint)-1))        return 0;
 667
 668         head = (tHeapHead*)Ptr - 1;
 669
 670         Heap_int_WatchBlock( head, true );
 671
 672         return 0;
 673 }
 674
 675 /**
 676  */
 677 void Heap_Validate(void)
 678 {
 679         // Call dump non-verbosely.
 680         // - If a heap error is detected, it'll print
 681         Heap_ValidateDump(0);
 682 }
 683
 684 void Heap_Dump(void)
 685 {
 686         Heap_ValidateDump(1);
 687 }
 688
 689 void Heap_ValidateDump(int bVerbose)
 690 {
 691         tHeapHead       *head, *badHead;
 692         tHeapFoot       *foot = NULL;
 693         static int      in_heap_dump;
 694
 695         if( in_heap_dump )      return;
 696
 697         in_heap_dump = 1;
 698
 699         head = gHeapStart;
 700         while( (Uint)head < (Uint)gHeapEnd )
 701         {
 702                 foot = Heap_ThisFoot(head);
 703
 704                 if( bVerbose )
 705                 {
 706                         Log_Log("Heap", "%p (%P): 0x%08x (%i) %4C",
 707                                 head, MM_GetPhysAddr(head), head->Size, head->ValidSize, &head->Magic);
 708                         Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 709                         if(head->File) {
 710                                 Log_Log("Heap", "%sowned by %s:%i",
 711                                         (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 712                         }
 713                 }
 714
 715                 // Sanity Check Header
 716                 if(head->Size == 0) {
 717                         Log_Warning("Heap", "HALTED - Size is zero");
 718                         break;
 719                 }
 720                 if(head->Size & (MIN_SIZE-1)) {
 721                         Log_Warning("Heap", "HALTED - Size is malaligned");
 722                         break;
 723                 }
 724                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 725                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 726                         break;
 727                 }
 728
 729                 // Check footer
 730                 if(foot->Magic != MAGIC_FOOT) {
 731                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 732                         break;
 733                 }
 734                 if(head != foot->Head) {
 735                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 736                         break;
 737                 }
 738
 739                 if( bVerbose )
 740                 {
 741                         Log_Log("Heap", "");
 742                 }
 743
 744                 // All OK? Go to next
 745                 head = foot->NextHead;
 746         }
 747
 748         // If the heap is valid, ok!
 749         if( (tVAddr)head == (tVAddr)gHeapEnd ) {
 750                 in_heap_dump = 0;
 751                 return ;
 752         }
 753
 754         // Check for a bad return
 755         if( (tVAddr)head >= (tVAddr)gHeapEnd ) {
 756                 in_heap_dump = 0;
 757                 return ;
 758         }
 759
 760         // If not verbose, we need to dump the failing block
 761         if( !bVerbose )
 762         {
 763                 Log_Log("Heap", "%p (%P): 0x%08lx %i %4C",
 764                         head, MM_GetPhysAddr(head), head->Size, head->ValidSize, &head->Magic);
 765                 if(foot)
 766                         Log_Log("Heap", "Foot %p = {Head:%p,Magic:%4C}", foot, foot->Head, &foot->Magic);
 767                 if(head->File) {
 768                         Log_Log("Heap", "%sowned by %s:%i",
 769                                 (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 770                 }
 771                 Log_Log("Heap", "");
 772         }
 773
 774         badHead = head;
 775
 776         // Work backwards
 777         foot = Heap_PrevFoot(gHeapEnd);
 778         Log_Log("Heap", "==== Going Backwards ==== (from %p)", foot);
 779         head = foot->Head;
 780         while( (tVAddr)head >= (tVAddr)badHead )
 781         {
 782                 Log_Log("Heap", "%p (%P): 0x%08lx %i %4C",
 783                         head, MM_GetPhysAddr(head), head->Size, head->ValidSize, &head->Magic);
 784                 Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 785                 if(head->File)
 786                         Log_Log("Heap", "%sowned by %s:%i",
 787                                 (head->Magic!=MAGIC_USED?"was ":""),
 788                                 head->File, head->Line);
 789                 Log_Log("Heap", "");
 790
 791                 // Sanity Check Header
 792                 if(head->Size == 0) {
 793                         Log_Warning("Heap", "HALTED - Size is zero");
 794                         break;
 795                 }
 796                 if(head->Size & (MIN_SIZE-1)) {
 797                         Log_Warning("Heap", " - Size is malaligned (&0x%x)", ~(MIN_SIZE-1));
 798                         break ;
 799                 }
 800                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 801                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 802                         break;
 803                 }
 804
 805                 // Check footer
 806                 if(foot->Magic != MAGIC_FOOT) {
 807                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 808                         break;
 809                 }
 810                 if(head != foot->Head) {
 811                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 812                         break;
 813                 }
 814
 815                 if(head == badHead)     break;
 816
 817                 foot = Heap_PrevFoot(head);
 818                 head = foot->Head;
 819                 Log_Debug("Heap", "head=%p", head);
 820         }
 821
 822         Panic("Heap_Dump - Heap is corrupted, kernel panic! (%p)", badHead);
 823 }
 824
 825 void Heap_Stats(void)
 826 {
 827          int    nBlocks = 0;
 828          int    nFree = 0;
 829          int    totalBytes = 0;
 830          int    freeBytes = 0;
 831          int    maxAlloc=0, minAlloc=-1;
 832          int    avgAlloc, frag, overhead;
 833
 834         for( tHeapHead *head = gHeapStart; head < gHeapEnd; head = Heap_NextHead(head) )
 835         {
 836                 nBlocks ++;
 837                 totalBytes += head->Size;
 838                 if( head->Magic == MAGIC_FREE )
 839                 {
 840                         nFree ++;
 841                         freeBytes += head->Size;
 842                 }
 843                 else if( head->Magic == MAGIC_USED) {
 844                         if(maxAlloc < head->Size)       maxAlloc = head->Size;
 845                         if(minAlloc == -1 || minAlloc > head->Size)
 846                                 minAlloc = head->Size;
 847                 }
 848                 else {
 849                         Log_Warning("Heap", "Magic on %p invalid, skipping remainder of heap", head);
 850                         break;
 851                 }
 852
 853                 // Print the block info?
 854                 #if 1
 855                 if( head->Magic == MAGIC_FREE )
 856                         Log_Debug("Heap", "%p (%P) - 0x%x free",
 857                                 head->Data, MM_GetPhysAddr(&head->Data), head->Size);
 858                 else
 859                         Log_Debug("Heap", "%p (%P) - 0x%x (%i) Owned by %s:%i (%lli ms old)",
 860                                 head->Data, MM_GetPhysAddr(&head->Data), head->Size,
 861                                 head->ValidSize, head->File, head->Line,
 862                                 now() - head->AllocateTime
 863                                 );
 864                 #endif
 865         }
 866
 867         Log_Log("Heap", "%i blocks (0x%x bytes)", nBlocks, totalBytes);
 868         Log_Log("Heap", "%i free blocks (0x%x bytes)", nFree, freeBytes);
 869         if(nBlocks != 0)
 870                 frag = (nFree-1)*10000/nBlocks;
 871         else
 872                 frag = 0;
 873         Log_Log("Heap", "%i.%02i%% Heap Fragmentation", frag/100, frag%100);
 874         if(nBlocks <= nFree)
 875                 avgAlloc = 0;
 876         else
 877                 avgAlloc = (totalBytes-freeBytes)/(nBlocks-nFree);
 878         if(avgAlloc != 0)
 879                 overhead = (sizeof(tHeapFoot)+sizeof(tHeapHead))*10000/avgAlloc;
 880         else
 881                 overhead = 0;
 882         Log_Log("Heap", "Average allocation: %i bytes, Average Overhead: %i.%02i%%",
 883                 avgAlloc, overhead/100, overhead%100
 884                 );
 885         Log_Log("Heap", "Smallest Block: %i bytes, Largest: %i bytes",
 886                 minAlloc, maxAlloc);
 887
 888         // Scan and get distribution
 889         #if 1
 890         if(nBlocks > 0)
 891         {
 892                 struct {
 893                         Uint    Size;
 894                         Uint    Count;
 895                 }       sizeCounts[nBlocks];
 896                  int    i;
 897
 898                 memset(sizeCounts, 0, nBlocks*sizeof(sizeCounts[0]));
 899
 900                 for(tHeapHead *head = gHeapStart; head < gHeapEnd; head = (void*)( (tVAddr)head + head->Size ) )
 901                 {
 902                         for( i = 0; i < nBlocks; i ++ ) {
 903                                 if( sizeCounts[i].Size == 0 )
 904                                         break;
 905                                 if( sizeCounts[i].Size == head->Size )
 906                                         break;
 907                         }
 908                         // Should never reach this part (in a non-concurrent case)
 909                         if( i == nBlocks )      continue;
 910                         sizeCounts[i].Size = head->Size;
 911                         sizeCounts[i].Count ++;
 912                         #if 0
 913                         Log("Heap_Stats: %i %p - 0x%x bytes (%s) (%i)", nBlocks, head,
 914                                 head->Size, (head->Magic==MAGIC_FREE?"FREE":"used"), i
 915                                 );
 916                         Log("Heap_Stats: sizeCounts[%i] = {Size:0x%x, Count: %i}", i,
 917                                 sizeCounts[i].Size, sizeCounts[i].Count);
 918                         #endif
 919                 }
 920
 921                 for( i = 0; i < nBlocks && sizeCounts[i].Count; i ++ )
 922                 {
 923                         Log("Heap_Stats: 0x%x - %i blocks",
 924                                 sizeCounts[i].Size, sizeCounts[i].Count
 925                                 );
 926                 }
 927         }
 928         #endif
 929 }
 930
 931 // === EXPORTS ===
 932 EXPORT(Heap_Allocate);
 933 EXPORT(Heap_AllocateZero);
 934 EXPORT(Heap_Reallocate);
 935 EXPORT(Heap_Deallocate);
 936 EXPORT(Heap_IsHeapAddr);