12 #define USE_DL_PREFIX 1
14 #include "mono-codeman.h"
15 #include "mono-mmap.h"
16 #include "mono-counters.h"
18 #include <mono/metadata/profiler-private.h>
19 #ifdef HAVE_VALGRIND_MEMCHECK_H
20 #include <valgrind/memcheck.h>
23 #include <mono/utils/mono-os-mutex.h>
26 static uintptr_t code_memory_used = 0;
27 static size_t dynamic_code_alloc_count;
28 static size_t dynamic_code_bytes_count;
29 static size_t dynamic_code_frees_count;
30 static MonoCodeManagerCallbacks code_manager_callbacks;
33 * AMD64 processors maintain icache coherency only for pages which are
34 * marked executable. Also, windows DEP requires us to obtain executable memory from
35 * malloc when using dynamic code managers. The system malloc can't do this so we use a
36 * slighly modified version of Doug Lea's Malloc package for this purpose:
37 * http://g.oswego.edu/dl/html/malloc.html
42 #if defined(__ia64__) || defined(__x86_64__) || defined (_WIN64)
44 * We require 16 byte alignment on amd64 so the fp literals embedded in the code are
45 * properly aligned for SSE2.
52 /* if a chunk has less than this amount of free space it's considered full */
53 #define MAX_WASTAGE 32
57 #define ARCH_MAP_FLAGS MONO_MMAP_32BIT
59 #define ARCH_MAP_FLAGS 0
62 #define MONO_PROT_RWX (MONO_MMAP_READ|MONO_MMAP_WRITE|MONO_MMAP_EXEC)
64 typedef struct _CodeChunck CodeChunk;
76 unsigned int flags: 8;
77 /* this number of bytes is available to resolve addresses far in memory */
78 unsigned int bsize: 24;
81 struct _MonoCodeManager {
89 #define ALIGN_INT(val,alignment) (((val) + (alignment - 1)) & ~(alignment - 1))
91 #define VALLOC_FREELIST_SIZE 16
93 static mono_mutex_t valloc_mutex;
94 static GHashTable *valloc_freelists;
97 codechunk_valloc (void *preferred, guint32 size)
102 if (!valloc_freelists) {
103 mono_os_mutex_init_recursive (&valloc_mutex);
104 valloc_freelists = g_hash_table_new (NULL, NULL);
108 * Keep a small freelist of memory blocks to decrease pressure on the kernel memory subsystem to avoid #3321.
110 mono_os_mutex_lock (&valloc_mutex);
111 freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
113 ptr = freelist->data;
114 memset (ptr, 0, size);
115 freelist = g_slist_delete_link (freelist, freelist);
116 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
118 ptr = mono_valloc (preferred, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
119 if (!ptr && preferred)
120 ptr = mono_valloc (NULL, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
122 mono_os_mutex_unlock (&valloc_mutex);
127 codechunk_vfree (void *ptr, guint32 size)
131 mono_os_mutex_lock (&valloc_mutex);
132 freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
133 if (!freelist || g_slist_length (freelist) < VALLOC_FREELIST_SIZE) {
134 freelist = g_slist_prepend (freelist, ptr);
135 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
137 mono_vfree (ptr, size, MONO_MEM_ACCOUNT_CODE);
139 mono_os_mutex_unlock (&valloc_mutex);
143 codechunk_cleanup (void)
148 if (!valloc_freelists)
150 g_hash_table_iter_init (&iter, valloc_freelists);
151 while (g_hash_table_iter_next (&iter, &key, &value)) {
152 GSList *freelist = (GSList *) value;
155 for (l = freelist; l; l = l->next) {
156 mono_vfree (l->data, GPOINTER_TO_UINT (key), MONO_MEM_ACCOUNT_CODE);
158 g_slist_free (freelist);
160 g_hash_table_destroy (valloc_freelists);
164 mono_code_manager_init (void)
166 mono_counters_register ("Dynamic code allocs", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_alloc_count);
167 mono_counters_register ("Dynamic code bytes", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_bytes_count);
168 mono_counters_register ("Dynamic code frees", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_frees_count);
172 mono_code_manager_cleanup (void)
174 codechunk_cleanup ();
178 mono_code_manager_install_callbacks (MonoCodeManagerCallbacks* callbacks)
180 code_manager_callbacks = *callbacks;
184 * mono_code_manager_new:
186 * Creates a new code manager. A code manager can be used to allocate memory
187 * suitable for storing native code that can be later executed.
188 * A code manager allocates memory from the operating system in large chunks
189 * (typically 64KB in size) so that many methods can be allocated inside them
190 * close together, improving cache locality.
192 * Returns: the new code manager
195 mono_code_manager_new (void)
197 return (MonoCodeManager *) g_malloc0 (sizeof (MonoCodeManager));
201 * mono_code_manager_new_dynamic:
203 * Creates a new code manager suitable for holding native code that can be
204 * used for single or small methods that need to be deallocated independently
205 * of other native code.
207 * Returns: the new code manager
210 mono_code_manager_new_dynamic (void)
212 MonoCodeManager *cman = mono_code_manager_new ();
219 free_chunklist (CodeChunk *chunk)
223 #if defined(HAVE_VALGRIND_MEMCHECK_H) && defined (VALGRIND_JIT_UNREGISTER_MAP)
224 int valgrind_unregister = 0;
225 if (RUNNING_ON_VALGRIND)
226 valgrind_unregister = 1;
227 #define valgrind_unregister(x) do { if (valgrind_unregister) { VALGRIND_JIT_UNREGISTER_MAP(NULL,x); } } while (0)
229 #define valgrind_unregister(x)
234 mono_profiler_code_chunk_destroy ((gpointer) dead->data);
235 if (code_manager_callbacks.chunk_destroy)
236 code_manager_callbacks.chunk_destroy ((gpointer)dead->data);
238 if (dead->flags == CODE_FLAG_MMAP) {
239 codechunk_vfree (dead->data, dead->size);
240 /* valgrind_unregister(dead->data); */
241 } else if (dead->flags == CODE_FLAG_MALLOC) {
244 code_memory_used -= dead->size;
250 * mono_code_manager_destroy:
251 * @cman: a code manager
253 * Free all the memory associated with the code manager @cman.
256 mono_code_manager_destroy (MonoCodeManager *cman)
258 free_chunklist (cman->full);
259 free_chunklist (cman->current);
264 * mono_code_manager_invalidate:
265 * @cman: a code manager
267 * Fill all the memory with an invalid native code value
268 * so that any attempt to execute code allocated in the code
269 * manager @cman will fail. This is used for debugging purposes.
272 mono_code_manager_invalidate (MonoCodeManager *cman)
276 #if defined(__i386__) || defined(__x86_64__)
277 int fill_value = 0xcc; /* x86 break */
279 int fill_value = 0x2a;
282 for (chunk = cman->current; chunk; chunk = chunk->next)
283 memset (chunk->data, fill_value, chunk->size);
284 for (chunk = cman->full; chunk; chunk = chunk->next)
285 memset (chunk->data, fill_value, chunk->size);
289 * mono_code_manager_set_read_only:
290 * @cman: a code manager
292 * Make the code manager read only, so further allocation requests cause an assert.
295 mono_code_manager_set_read_only (MonoCodeManager *cman)
297 cman->read_only = TRUE;
301 * mono_code_manager_foreach:
302 * @cman: a code manager
303 * @func: a callback function pointer
304 * @user_data: additional data to pass to @func
306 * Invokes the callback @func for each different chunk of memory allocated
307 * in the code manager @cman.
310 mono_code_manager_foreach (MonoCodeManager *cman, MonoCodeManagerFunc func, void *user_data)
313 for (chunk = cman->current; chunk; chunk = chunk->next) {
314 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
317 for (chunk = cman->full; chunk; chunk = chunk->next) {
318 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
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
328 #if defined(__ppc__) || defined(__powerpc__)
331 #if defined(TARGET_ARM64)
336 new_codechunk (CodeChunk *last, int dynamic, int size)
338 int minsize, flags = CODE_FLAG_MMAP;
339 int chunk_size, bsize = 0;
340 int pagesize, valloc_granule;
345 flags = CODE_FLAG_MALLOC;
348 pagesize = mono_pagesize ();
349 valloc_granule = mono_valloc_granule ();
353 flags = CODE_FLAG_MALLOC;
355 minsize = MAX (pagesize * MIN_PAGES, valloc_granule);
357 chunk_size = minsize;
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);
365 chunk_size += valloc_granule - 1;
366 chunk_size &= ~ (valloc_granule - 1);
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;
374 bsize = chunk_size / BIND_ROOM;
375 if (bsize < MIN_BSIZE)
377 bsize += MIN_ALIGN -1;
378 bsize &= ~ (MIN_ALIGN - 1);
379 if (chunk_size - size < bsize) {
380 chunk_size = size + bsize;
382 chunk_size += valloc_granule - 1;
383 chunk_size &= ~ (valloc_granule - 1);
388 if (flags == CODE_FLAG_MALLOC) {
389 ptr = dlmemalign (MIN_ALIGN, chunk_size + MIN_ALIGN - 1);
393 /* Try to allocate code chunks next to each other to help the VM */
396 ptr = codechunk_valloc ((guint8*)last->data + last->size, chunk_size);
398 ptr = codechunk_valloc (NULL, chunk_size);
403 if (flags == CODE_FLAG_MALLOC) {
405 /* Make sure the thunks area is zeroed */
406 memset (ptr, 0, bsize);
410 chunk = (CodeChunk *) g_malloc (sizeof (CodeChunk));
412 if (flags == CODE_FLAG_MALLOC)
415 mono_vfree (ptr, chunk_size, MONO_MEM_ACCOUNT_CODE);
419 chunk->size = chunk_size;
420 chunk->data = (char *) ptr;
421 chunk->flags = flags;
423 chunk->bsize = bsize;
424 if (code_manager_callbacks.chunk_new)
425 code_manager_callbacks.chunk_new ((gpointer)chunk->data, chunk->size);
426 mono_profiler_code_chunk_new((gpointer) chunk->data, chunk->size);
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);*/
435 * mono_code_manager_reserve:
436 * @cman: a code manager
437 * @size: size of memory to allocate
438 * @alignment: power of two alignment value
440 * Allocates at least @size bytes of memory inside the code manager @cman.
442 * Returns: the pointer to the allocated memory or #NULL on failure
445 mono_code_manager_reserve_align (MonoCodeManager *cman, int size, int alignment)
447 CodeChunk *chunk, *prev;
449 guint32 align_mask = alignment - 1;
451 g_assert (!cman->read_only);
453 /* eventually allow bigger alignments, but we need to fix the dynamic alloc code to
456 g_assert (alignment <= MIN_ALIGN);
459 ++dynamic_code_alloc_count;
460 dynamic_code_bytes_count += size;
463 if (!cman->current) {
464 cman->current = new_codechunk (cman->last, cman->dynamic, size);
467 cman->last = cman->current;
470 for (chunk = cman->current; chunk; chunk = chunk->next) {
471 if (ALIGN_INT (chunk->pos, alignment) + size <= chunk->size) {
472 chunk->pos = ALIGN_INT (chunk->pos, alignment);
473 /* Align the chunk->data we add to chunk->pos */
474 /* or we can't guarantee proper alignment */
475 ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
476 chunk->pos = ((char*)ptr - chunk->data) + size;
481 * no room found, move one filled chunk to cman->full
482 * to keep cman->current from growing too much
485 for (chunk = cman->current; chunk; prev = chunk, chunk = chunk->next) {
486 if (chunk->pos + MIN_ALIGN * 4 <= chunk->size)
489 prev->next = chunk->next;
491 cman->current = chunk->next;
493 chunk->next = cman->full;
497 chunk = new_codechunk (cman->last, cman->dynamic, size);
500 chunk->next = cman->current;
501 cman->current = chunk;
502 cman->last = cman->current;
503 chunk->pos = ALIGN_INT (chunk->pos, alignment);
504 /* Align the chunk->data we add to chunk->pos */
505 /* or we can't guarantee proper alignment */
506 ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
507 chunk->pos = ((char*)ptr - chunk->data) + size;
512 * mono_code_manager_reserve:
513 * @cman: a code manager
514 * @size: size of memory to allocate
516 * Allocates at least @size bytes of memory inside the code manager @cman.
518 * Returns: the pointer to the allocated memory or #NULL on failure
521 mono_code_manager_reserve (MonoCodeManager *cman, int size)
523 return mono_code_manager_reserve_align (cman, size, MIN_ALIGN);
527 * mono_code_manager_commit:
528 * @cman: a code manager
529 * @data: the pointer returned by mono_code_manager_reserve ()
530 * @size: the size requested in the call to mono_code_manager_reserve ()
531 * @newsize: the new size to reserve
533 * If we reserved too much room for a method and we didn't allocate
534 * already from the code manager, we can get back the excess allocation
535 * for later use in the code manager.
538 mono_code_manager_commit (MonoCodeManager *cman, void *data, int size, int newsize)
540 g_assert (newsize <= size);
542 if (cman->current && (size != newsize) && (data == cman->current->data + cman->current->pos - size)) {
543 cman->current->pos -= size - newsize;
548 * mono_code_manager_size:
549 * @cman: a code manager
550 * @used_size: pointer to an integer for the result
552 * This function can be used to get statistics about a code manager:
553 * the integer pointed to by @used_size will contain how much
554 * memory is actually used inside the code managed @cman.
556 * Returns: the amount of memory allocated in @cman
559 mono_code_manager_size (MonoCodeManager *cman, int *used_size)
564 for (chunk = cman->current; chunk; chunk = chunk->next) {
568 for (chunk = cman->full; chunk; chunk = chunk->next) {