mono/utils/mono-codeman.c

   1 /**
   2  * \file
   3  */
   4
   5 #include "config.h"
   6
   7 #ifdef HAVE_UNISTD_H
   8 #include <unistd.h>
   9 #endif
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <assert.h>
  13 #include <glib.h>
  14
  15 /* For dlmalloc.h */
  16 #define USE_DL_PREFIX 1
  17
  18 #include "mono-codeman.h"
  19 #include "mono-mmap.h"
  20 #include "mono-counters.h"
  21 #include "dlmalloc.h"
  22 #include <mono/metadata/profiler-private.h>
  23 #ifdef HAVE_VALGRIND_MEMCHECK_H
  24 #include <valgrind/memcheck.h>
  25 #endif
  26
  27 #include <mono/utils/mono-os-mutex.h>
  28
  29
  30 static uintptr_t code_memory_used = 0;
  31 static size_t dynamic_code_alloc_count;
  32 static size_t dynamic_code_bytes_count;
  33 static size_t dynamic_code_frees_count;
  34 static const MonoCodeManagerCallbacks *code_manager_callbacks;
  35
  36 /*
  37  * AMD64 processors maintain icache coherency only for pages which are
  38  * marked executable. Also, windows DEP requires us to obtain executable memory from
  39  * malloc when using dynamic code managers. The system malloc can't do this so we use a
  40  * slighly modified version of Doug Lea's Malloc package for this purpose:
  41  * http://g.oswego.edu/dl/html/malloc.html
  42  */
  43
  44 #define MIN_PAGES 16
  45
  46 #if defined(__x86_64__) || defined (_WIN64)
  47 /*
  48  * We require 16 byte alignment on amd64 so the fp literals embedded in the code are
  49  * properly aligned for SSE2.
  50  */
  51 #define MIN_ALIGN 16
  52 #else
  53 #define MIN_ALIGN 8
  54 #endif
  55
  56 /* if a chunk has less than this amount of free space it's considered full */
  57 #define MAX_WASTAGE 32
  58 #define MIN_BSIZE 32
  59
  60 #ifdef __x86_64__
  61 #define ARCH_MAP_FLAGS MONO_MMAP_32BIT
  62 #else
  63 #define ARCH_MAP_FLAGS 0
  64 #endif
  65
  66 #define MONO_PROT_RWX (MONO_MMAP_READ|MONO_MMAP_WRITE|MONO_MMAP_EXEC|MONO_MMAP_JIT)
  67
  68 typedef struct _CodeChunck CodeChunk;
  69
  70 enum {
  71         CODE_FLAG_MMAP,
  72         CODE_FLAG_MALLOC
  73 };
  74
  75 struct _CodeChunck {
  76         char *data;
  77         int pos;
  78         int size;
  79         CodeChunk *next;
  80         unsigned int flags: 8;
  81         /* this number of bytes is available to resolve addresses far in memory */
  82         unsigned int bsize: 24;
  83 };
  84
  85 struct _MonoCodeManager {
  86         int dynamic;
  87         int read_only;
  88         CodeChunk *current;
  89         CodeChunk *full;
  90         CodeChunk *last;
  91 };
  92
  93 #define ALIGN_INT(val,alignment) (((val) + (alignment - 1)) & ~(alignment - 1))
  94
  95 #define VALLOC_FREELIST_SIZE 16
  96
  97 static mono_mutex_t valloc_mutex;
  98 static GHashTable *valloc_freelists;
  99
 100 static void*
 101 codechunk_valloc (void *preferred, guint32 size)
 102 {
 103         void *ptr;
 104         GSList *freelist;
 105
 106         if (!valloc_freelists) {
 107                 mono_os_mutex_init_recursive (&valloc_mutex);
 108                 valloc_freelists = g_hash_table_new (NULL, NULL);
 109         }
 110
 111         /*
 112          * Keep a small freelist of memory blocks to decrease pressure on the kernel memory subsystem to avoid #3321.
 113          */
 114         mono_os_mutex_lock (&valloc_mutex);
 115         freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
 116         if (freelist) {
 117                 ptr = freelist->data;
 118                 memset (ptr, 0, size);
 119                 freelist = g_slist_delete_link (freelist, freelist);
 120                 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
 121         } else {
 122                 ptr = mono_valloc (preferred, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
 123                 if (!ptr && preferred)
 124                         ptr = mono_valloc (NULL, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
 125         }
 126         mono_os_mutex_unlock (&valloc_mutex);
 127         return ptr;
 128 }
 129
 130 static void
 131 codechunk_vfree (void *ptr, guint32 size)
 132 {
 133         GSList *freelist;
 134
 135         mono_os_mutex_lock (&valloc_mutex);
 136         freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
 137         if (!freelist || g_slist_length (freelist) < VALLOC_FREELIST_SIZE) {
 138                 freelist = g_slist_prepend (freelist, ptr);
 139                 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
 140         } else {
 141                 mono_vfree (ptr, size, MONO_MEM_ACCOUNT_CODE);
 142         }
 143         mono_os_mutex_unlock (&valloc_mutex);
 144 }
 145
 146 static void
 147 codechunk_cleanup (void)
 148 {
 149         GHashTableIter iter;
 150         gpointer key, value;
 151
 152         if (!valloc_freelists)
 153                 return;
 154         g_hash_table_iter_init (&iter, valloc_freelists);
 155         while (g_hash_table_iter_next (&iter, &key, &value)) {
 156                 GSList *freelist = (GSList *) value;
 157                 GSList *l;
 158
 159                 for (l = freelist; l; l = l->next) {
 160                         mono_vfree (l->data, GPOINTER_TO_UINT (key), MONO_MEM_ACCOUNT_CODE);
 161                 }
 162                 g_slist_free (freelist);
 163         }
 164         g_hash_table_destroy (valloc_freelists);
 165 }
 166
 167 void
 168 mono_code_manager_init (void)
 169 {
 170         mono_counters_register ("Dynamic code allocs", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_alloc_count);
 171         mono_counters_register ("Dynamic code bytes", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_bytes_count);
 172         mono_counters_register ("Dynamic code frees", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_frees_count);
 173 }
 174
 175 void
 176 mono_code_manager_cleanup (void)
 177 {
 178         codechunk_cleanup ();
 179 }
 180
 181 void
 182 mono_code_manager_install_callbacks (const MonoCodeManagerCallbacks* callbacks)
 183 {
 184         code_manager_callbacks = callbacks;
 185 }
 186
 187 /**
 188  * mono_code_manager_new:
 189  *
 190  * Creates a new code manager. A code manager can be used to allocate memory
 191  * suitable for storing native code that can be later executed.
 192  * A code manager allocates memory from the operating system in large chunks
 193  * (typically 64KB in size) so that many methods can be allocated inside them
 194  * close together, improving cache locality.
 195  *
 196  * Returns: the new code manager
 197  */
 198 MonoCodeManager*
 199 mono_code_manager_new (void)
 200 {
 201         return (MonoCodeManager *) g_malloc0 (sizeof (MonoCodeManager));
 202 }
 203
 204 /**
 205  * mono_code_manager_new_dynamic:
 206  *
 207  * Creates a new code manager suitable for holding native code that can be
 208  * used for single or small methods that need to be deallocated independently
 209  * of other native code.
 210  *
 211  * Returns: the new code manager
 212  */
 213 MonoCodeManager*
 214 mono_code_manager_new_dynamic (void)
 215 {
 216         MonoCodeManager *cman = mono_code_manager_new ();
 217         cman->dynamic = 1;
 218         return cman;
 219 }
 220
 221
 222 static void
 223 free_chunklist (CodeChunk *chunk)
 224 {
 225         CodeChunk *dead;
 226
 227 #if defined(HAVE_VALGRIND_MEMCHECK_H) && defined (VALGRIND_JIT_UNREGISTER_MAP)
 228         int valgrind_unregister = 0;
 229         if (RUNNING_ON_VALGRIND)
 230                 valgrind_unregister = 1;
 231 #define valgrind_unregister(x) do { if (valgrind_unregister) { VALGRIND_JIT_UNREGISTER_MAP(NULL,x); } } while (0)
 232 #else
 233 #define valgrind_unregister(x)
 234 #endif
 235
 236         for (; chunk; ) {
 237                 dead = chunk;
 238                 MONO_PROFILER_RAISE (jit_chunk_destroyed, ((mono_byte *) dead->data));
 239                 if (code_manager_callbacks)
 240                         code_manager_callbacks->chunk_destroy (dead->data);
 241                 chunk = chunk->next;
 242                 if (dead->flags == CODE_FLAG_MMAP) {
 243                         codechunk_vfree (dead->data, dead->size);
 244                         /* valgrind_unregister(dead->data); */
 245                 } else if (dead->flags == CODE_FLAG_MALLOC) {
 246                         dlfree (dead->data);
 247                 }
 248                 code_memory_used -= dead->size;
 249                 g_free (dead);
 250         }
 251 }
 252
 253 /**
 254  * mono_code_manager_destroy:
 255  * \param cman a code manager
 256  * Free all the memory associated with the code manager \p cman.
 257  */
 258 void
 259 mono_code_manager_destroy (MonoCodeManager *cman)
 260 {
 261         free_chunklist (cman->full);
 262         free_chunklist (cman->current);
 263         g_free (cman);
 264 }
 265
 266 /**
 267  * mono_code_manager_invalidate:
 268  * \param cman a code manager
 269  * Fill all the memory with an invalid native code value
 270  * so that any attempt to execute code allocated in the code
 271  * manager \p cman will fail. This is used for debugging purposes.
 272  */
 273 void
 274 mono_code_manager_invalidate (MonoCodeManager *cman)
 275 {
 276         CodeChunk *chunk;
 277
 278 #if defined(__i386__) || defined(__x86_64__)
 279         int fill_value = 0xcc; /* x86 break */
 280 #else
 281         int fill_value = 0x2a;
 282 #endif
 283
 284         for (chunk = cman->current; chunk; chunk = chunk->next)
 285                 memset (chunk->data, fill_value, chunk->size);
 286         for (chunk = cman->full; chunk; chunk = chunk->next)
 287                 memset (chunk->data, fill_value, chunk->size);
 288 }
 289
 290 /**
 291  * mono_code_manager_set_read_only:
 292  * \param cman a code manager
 293  * Make the code manager read only, so further allocation requests cause an assert.
 294  */
 295 void
 296 mono_code_manager_set_read_only (MonoCodeManager *cman)
 297 {
 298         cman->read_only = TRUE;
 299 }
 300
 301 /**
 302  * mono_code_manager_foreach:
 303  * \param cman a code manager
 304  * \param func a callback function pointer
 305  * \param user_data additional data to pass to \p func
 306   * Invokes the callback \p func for each different chunk of memory allocated
 307  * in the code manager \p cman.
 308  */
 309 void
 310 mono_code_manager_foreach (MonoCodeManager *cman, MonoCodeManagerFunc func, void *user_data)
 311 {
 312         CodeChunk *chunk;
 313         for (chunk = cman->current; chunk; chunk = chunk->next) {
 314                 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
 315                         return;
 316         }
 317         for (chunk = cman->full; chunk; chunk = chunk->next) {
 318                 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
 319                         return;
 320         }
 321 }
 322
 323 /* BIND_ROOM is the divisor for the chunck of code size dedicated
 324  * to binding branches (branches not reachable with the immediate displacement)
 325  * bind_size = size/BIND_ROOM;
 326  * we should reduce it and make MIN_PAGES bigger for such systems
 327  */
 328 #if defined(__ppc__) || defined(__powerpc__)
 329 #define BIND_ROOM 4
 330 #endif
 331 #if defined(TARGET_ARM64)
 332 #define BIND_ROOM 4
 333 #endif
 334
 335 static CodeChunk*
 336 new_codechunk (CodeChunk *last, int dynamic, int size)
 337 {
 338         int minsize, flags = CODE_FLAG_MMAP;
 339         int chunk_size, bsize = 0;
 340         int pagesize, valloc_granule;
 341         CodeChunk *chunk;
 342         void *ptr;
 343
 344 #ifdef FORCE_MALLOC
 345         flags = CODE_FLAG_MALLOC;
 346 #endif
 347
 348         pagesize = mono_pagesize ();
 349         valloc_granule = mono_valloc_granule ();
 350
 351         if (dynamic) {
 352                 chunk_size = size;
 353                 flags = CODE_FLAG_MALLOC;
 354         } else {
 355                 minsize = MAX (pagesize * MIN_PAGES, valloc_granule);
 356                 if (size < minsize)
 357                         chunk_size = minsize;
 358                 else {
 359                         /* Allocate MIN_ALIGN-1 more than we need so we can still */
 360                         /* guarantee MIN_ALIGN alignment for individual allocs    */
 361                         /* from mono_code_manager_reserve_align.                  */
 362                         size += MIN_ALIGN - 1;
 363                         size &= ~(MIN_ALIGN - 1);
 364                         chunk_size = size;
 365                         chunk_size += valloc_granule - 1;
 366                         chunk_size &= ~ (valloc_granule - 1);
 367                 }
 368         }
 369 #ifdef BIND_ROOM
 370         if (dynamic)
 371                 /* Reserve more space since there are no other chunks we might use if this one gets full */
 372                 bsize = (chunk_size * 2) / BIND_ROOM;
 373         else
 374                 bsize = chunk_size / BIND_ROOM;
 375         if (bsize < MIN_BSIZE)
 376                 bsize = MIN_BSIZE;
 377         bsize += MIN_ALIGN -1;
 378         bsize &= ~ (MIN_ALIGN - 1);
 379         if (chunk_size - size < bsize) {
 380                 chunk_size = size + bsize;
 381                 if (!dynamic) {
 382                         chunk_size += valloc_granule - 1;
 383                         chunk_size &= ~ (valloc_granule - 1);
 384                 }
 385         }
 386 #endif
 387
 388         if (flags == CODE_FLAG_MALLOC) {
 389                 ptr = dlmemalign (MIN_ALIGN, chunk_size + MIN_ALIGN - 1);
 390                 if (!ptr)
 391                         return NULL;
 392         } else {
 393                 /* Try to allocate code chunks next to each other to help the VM */
 394                 ptr = NULL;
 395                 if (last)
 396                         ptr = codechunk_valloc ((guint8*)last->data + last->size, chunk_size);
 397                 if (!ptr)
 398                         ptr = codechunk_valloc (NULL, chunk_size);
 399                 if (!ptr)
 400                         return NULL;
 401         }
 402
 403         if (flags == CODE_FLAG_MALLOC) {
 404 #ifdef BIND_ROOM
 405                 /* Make sure the thunks area is zeroed */
 406                 memset (ptr, 0, bsize);
 407 #endif
 408         }
 409
 410         chunk = (CodeChunk *) g_malloc (sizeof (CodeChunk));
 411         if (!chunk) {
 412                 if (flags == CODE_FLAG_MALLOC)
 413                         dlfree (ptr);
 414                 else
 415                         mono_vfree (ptr, chunk_size, MONO_MEM_ACCOUNT_CODE);
 416                 return NULL;
 417         }
 418         chunk->next = NULL;
 419         chunk->size = chunk_size;
 420         chunk->data = (char *) ptr;
 421         chunk->flags = flags;
 422         chunk->pos = bsize;
 423         chunk->bsize = bsize;
 424         if (code_manager_callbacks)
 425                 code_manager_callbacks->chunk_new (chunk->data, chunk->size);
 426         MONO_PROFILER_RAISE (jit_chunk_created, ((mono_byte *) chunk->data, chunk->size));
 427
 428         code_memory_used += chunk_size;
 429         mono_runtime_resource_check_limit (MONO_RESOURCE_JIT_CODE, code_memory_used);
 430         /*printf ("code chunk at: %p\n", ptr);*/
 431         return chunk;
 432 }
 433
 434 /**
 435  * mono_code_manager_reserve_align:
 436  * \param cman a code manager
 437  * \param size size of memory to allocate
 438  * \param alignment power of two alignment value
 439  * Allocates at least \p size bytes of memory inside the code manager \p cman.
 440  * \returns the pointer to the allocated memory or NULL on failure
 441  */
 442 void*
 443 mono_code_manager_reserve_align (MonoCodeManager *cman, int size, int alignment)
 444 {
 445         CodeChunk *chunk, *prev;
 446         void *ptr;
 447         guint32 align_mask = alignment - 1;
 448
 449         g_assert (!cman->read_only);
 450
 451         /* eventually allow bigger alignments, but we need to fix the dynamic alloc code to
 452          * handle this before
 453          */
 454         g_assert (alignment <= MIN_ALIGN);
 455
 456         if (cman->dynamic) {
 457                 ++dynamic_code_alloc_count;
 458                 dynamic_code_bytes_count += size;
 459         }
 460
 461         if (!cman->current) {
 462                 cman->current = new_codechunk (cman->last, cman->dynamic, size);
 463                 if (!cman->current)
 464                         return NULL;
 465                 cman->last = cman->current;
 466         }
 467
 468         for (chunk = cman->current; chunk; chunk = chunk->next) {
 469                 if (ALIGN_INT (chunk->pos, alignment) + size <= chunk->size) {
 470                         chunk->pos = ALIGN_INT (chunk->pos, alignment);
 471                         /* Align the chunk->data we add to chunk->pos */
 472                         /* or we can't guarantee proper alignment     */
 473                         ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
 474                         chunk->pos = ((char*)ptr - chunk->data) + size;
 475                         return ptr;
 476                 }
 477         }
 478         /*
 479          * no room found, move one filled chunk to cman->full
 480          * to keep cman->current from growing too much
 481          */
 482         prev = NULL;
 483         for (chunk = cman->current; chunk; prev = chunk, chunk = chunk->next) {
 484                 if (chunk->pos + MIN_ALIGN * 4 <= chunk->size)
 485                         continue;
 486                 if (prev) {
 487                         prev->next = chunk->next;
 488                 } else {
 489                         cman->current = chunk->next;
 490                 }
 491                 chunk->next = cman->full;
 492                 cman->full = chunk;
 493                 break;
 494         }
 495         chunk = new_codechunk (cman->last, cman->dynamic, size);
 496         if (!chunk)
 497                 return NULL;
 498         chunk->next = cman->current;
 499         cman->current = chunk;
 500         cman->last = cman->current;
 501         chunk->pos = ALIGN_INT (chunk->pos, alignment);
 502         /* Align the chunk->data we add to chunk->pos */
 503         /* or we can't guarantee proper alignment     */
 504         ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
 505         chunk->pos = ((char*)ptr - chunk->data) + size;
 506         return ptr;
 507 }
 508
 509 /**
 510  * mono_code_manager_reserve:
 511  * \param cman a code manager
 512  * \param size size of memory to allocate
 513  * Allocates at least \p size bytes of memory inside the code manager \p cman.
 514  * \returns the pointer to the allocated memory or NULL on failure
 515  */
 516 void*
 517 mono_code_manager_reserve (MonoCodeManager *cman, int size)
 518 {
 519         return mono_code_manager_reserve_align (cman, size, MIN_ALIGN);
 520 }
 521
 522 /**
 523  * mono_code_manager_commit:
 524  * \param cman a code manager
 525  * \param data the pointer returned by mono_code_manager_reserve ()
 526  * \param size the size requested in the call to mono_code_manager_reserve ()
 527  * \param newsize the new size to reserve
 528  * If we reserved too much room for a method and we didn't allocate
 529  * already from the code manager, we can get back the excess allocation
 530  * for later use in the code manager.
 531  */
 532 void
 533 mono_code_manager_commit (MonoCodeManager *cman, void *data, int size, int newsize)
 534 {
 535         g_assert (newsize <= size);
 536
 537         if (cman->current && (size != newsize) && (data == cman->current->data + cman->current->pos - size)) {
 538                 cman->current->pos -= size - newsize;
 539         }
 540 }
 541
 542 /**
 543  * mono_code_manager_size:
 544  * \param cman a code manager
 545  * \param used_size pointer to an integer for the result
 546  * This function can be used to get statistics about a code manager:
 547  * the integer pointed to by \p used_size will contain how much
 548  * memory is actually used inside the code managed \p cman.
 549  * \returns the amount of memory allocated in \p cman
 550  */
 551 int
 552 mono_code_manager_size (MonoCodeManager *cman, int *used_size)
 553 {
 554         CodeChunk *chunk;
 555         guint32 size = 0;
 556         guint32 used = 0;
 557         for (chunk = cman->current; chunk; chunk = chunk->next) {
 558                 size += chunk->size;
 559                 used += chunk->pos;
 560         }
 561         for (chunk = cman->full; chunk; chunk = chunk->next) {
 562                 size += chunk->size;
 563                 used += chunk->pos;
 564         }
 565         if (used_size)
 566                 *used_size = used;
 567         return size;
 568 }