12 #define USE_DL_PREFIX 1
14 #include "mono-codeman.h"
15 #include "mono-mmap.h"
16 #include "mono-counters.h"
18 #include <mono/io-layer/io-layer.h>
19 #include <mono/metadata/profiler-private.h>
20 #ifdef HAVE_VALGRIND_MEMCHECK_H
21 #include <valgrind/memcheck.h>
24 #include <mono/utils/mono-os-mutex.h>
27 static uintptr_t code_memory_used = 0;
28 static size_t dynamic_code_alloc_count;
29 static size_t dynamic_code_bytes_count;
30 static size_t dynamic_code_frees_count;
31 static MonoCodeManagerCallbacks code_manager_callbacks;
34 * AMD64 processors maintain icache coherency only for pages which are
35 * marked executable. Also, windows DEP requires us to obtain executable memory from
36 * malloc when using dynamic code managers. The system malloc can't do this so we use a
37 * slighly modified version of Doug Lea's Malloc package for this purpose:
38 * http://g.oswego.edu/dl/html/malloc.html
43 #if defined(__ia64__) || defined(__x86_64__) || defined (_WIN64)
45 * We require 16 byte alignment on amd64 so the fp literals embedded in the code are
46 * properly aligned for SSE2.
53 /* if a chunk has less than this amount of free space it's considered full */
54 #define MAX_WASTAGE 32
58 #define ARCH_MAP_FLAGS MONO_MMAP_32BIT
60 #define ARCH_MAP_FLAGS 0
63 #define MONO_PROT_RWX (MONO_MMAP_READ|MONO_MMAP_WRITE|MONO_MMAP_EXEC)
65 typedef struct _CodeChunck CodeChunk;
77 unsigned int flags: 8;
78 /* this number of bytes is available to resolve addresses far in memory */
79 unsigned int bsize: 24;
82 struct _MonoCodeManager {
90 #define ALIGN_INT(val,alignment) (((val) + (alignment - 1)) & ~(alignment - 1))
92 #define VALLOC_FREELIST_SIZE 16
94 static mono_mutex_t valloc_mutex;
95 static GHashTable *valloc_freelists;
98 codechunk_valloc (void *preferred, guint32 size)
103 if (!valloc_freelists) {
104 mono_os_mutex_init_recursive (&valloc_mutex);
105 valloc_freelists = g_hash_table_new (NULL, NULL);
109 * Keep a small freelist of memory blocks to decrease pressure on the kernel memory subsystem to avoid #3321.
111 mono_os_mutex_lock (&valloc_mutex);
112 freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
114 ptr = freelist->data;
115 memset (ptr, 0, size);
116 freelist = g_slist_delete_link (freelist, freelist);
117 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
119 ptr = mono_valloc (preferred, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
120 if (!ptr && preferred)
121 ptr = mono_valloc (NULL, size, MONO_PROT_RWX | ARCH_MAP_FLAGS, MONO_MEM_ACCOUNT_CODE);
123 mono_os_mutex_unlock (&valloc_mutex);
128 codechunk_vfree (void *ptr, guint32 size)
132 mono_os_mutex_lock (&valloc_mutex);
133 freelist = (GSList *) g_hash_table_lookup (valloc_freelists, GUINT_TO_POINTER (size));
134 if (!freelist || g_slist_length (freelist) < VALLOC_FREELIST_SIZE) {
135 freelist = g_slist_prepend (freelist, ptr);
136 g_hash_table_insert (valloc_freelists, GUINT_TO_POINTER (size), freelist);
138 mono_vfree (ptr, size, MONO_MEM_ACCOUNT_CODE);
140 mono_os_mutex_unlock (&valloc_mutex);
144 codechunk_cleanup (void)
149 if (!valloc_freelists)
151 g_hash_table_iter_init (&iter, valloc_freelists);
152 while (g_hash_table_iter_next (&iter, &key, &value)) {
153 GSList *freelist = (GSList *) value;
156 for (l = freelist; l; l = l->next) {
157 mono_vfree (l->data, GPOINTER_TO_UINT (key), MONO_MEM_ACCOUNT_CODE);
159 g_slist_free (freelist);
161 g_hash_table_destroy (valloc_freelists);
165 mono_code_manager_init (void)
167 mono_counters_register ("Dynamic code allocs", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_alloc_count);
168 mono_counters_register ("Dynamic code bytes", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_bytes_count);
169 mono_counters_register ("Dynamic code frees", MONO_COUNTER_JIT | MONO_COUNTER_ULONG, &dynamic_code_frees_count);
173 mono_code_manager_cleanup (void)
175 codechunk_cleanup ();
179 mono_code_manager_install_callbacks (MonoCodeManagerCallbacks* callbacks)
181 code_manager_callbacks = *callbacks;
185 * mono_code_manager_new:
187 * Creates a new code manager. A code manager can be used to allocate memory
188 * suitable for storing native code that can be later executed.
189 * A code manager allocates memory from the operating system in large chunks
190 * (typically 64KB in size) so that many methods can be allocated inside them
191 * close together, improving cache locality.
193 * Returns: the new code manager
196 mono_code_manager_new (void)
198 return (MonoCodeManager *) g_malloc0 (sizeof (MonoCodeManager));
202 * mono_code_manager_new_dynamic:
204 * Creates a new code manager suitable for holding native code that can be
205 * used for single or small methods that need to be deallocated independently
206 * of other native code.
208 * Returns: the new code manager
211 mono_code_manager_new_dynamic (void)
213 MonoCodeManager *cman = mono_code_manager_new ();
220 free_chunklist (CodeChunk *chunk)
224 #if defined(HAVE_VALGRIND_MEMCHECK_H) && defined (VALGRIND_JIT_UNREGISTER_MAP)
225 int valgrind_unregister = 0;
226 if (RUNNING_ON_VALGRIND)
227 valgrind_unregister = 1;
228 #define valgrind_unregister(x) do { if (valgrind_unregister) { VALGRIND_JIT_UNREGISTER_MAP(NULL,x); } } while (0)
230 #define valgrind_unregister(x)
235 mono_profiler_code_chunk_destroy ((gpointer) dead->data);
236 if (code_manager_callbacks.chunk_destroy)
237 code_manager_callbacks.chunk_destroy ((gpointer)dead->data);
239 if (dead->flags == CODE_FLAG_MMAP) {
240 codechunk_vfree (dead->data, dead->size);
241 /* valgrind_unregister(dead->data); */
242 } else if (dead->flags == CODE_FLAG_MALLOC) {
245 code_memory_used -= dead->size;
251 * mono_code_manager_destroy:
252 * @cman: a code manager
254 * Free all the memory associated with the code manager @cman.
257 mono_code_manager_destroy (MonoCodeManager *cman)
259 free_chunklist (cman->full);
260 free_chunklist (cman->current);
265 * mono_code_manager_invalidate:
266 * @cman: a code manager
268 * Fill all the memory with an invalid native code value
269 * so that any attempt to execute code allocated in the code
270 * manager @cman will fail. This is used for debugging purposes.
273 mono_code_manager_invalidate (MonoCodeManager *cman)
277 #if defined(__i386__) || defined(__x86_64__)
278 int fill_value = 0xcc; /* x86 break */
280 int fill_value = 0x2a;
283 for (chunk = cman->current; chunk; chunk = chunk->next)
284 memset (chunk->data, fill_value, chunk->size);
285 for (chunk = cman->full; chunk; chunk = chunk->next)
286 memset (chunk->data, fill_value, chunk->size);
290 * mono_code_manager_set_read_only:
291 * @cman: a code manager
293 * Make the code manager read only, so further allocation requests cause an assert.
296 mono_code_manager_set_read_only (MonoCodeManager *cman)
298 cman->read_only = TRUE;
302 * mono_code_manager_foreach:
303 * @cman: a code manager
304 * @func: a callback function pointer
305 * @user_data: additional data to pass to @func
307 * Invokes the callback @func for each different chunk of memory allocated
308 * in the code manager @cman.
311 mono_code_manager_foreach (MonoCodeManager *cman, MonoCodeManagerFunc func, void *user_data)
314 for (chunk = cman->current; chunk; chunk = chunk->next) {
315 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
318 for (chunk = cman->full; chunk; chunk = chunk->next) {
319 if (func (chunk->data, chunk->size, chunk->bsize, user_data))
324 /* BIND_ROOM is the divisor for the chunck of code size dedicated
325 * to binding branches (branches not reachable with the immediate displacement)
326 * bind_size = size/BIND_ROOM;
327 * we should reduce it and make MIN_PAGES bigger for such systems
329 #if defined(__ppc__) || defined(__powerpc__)
332 #if defined(TARGET_ARM64)
337 new_codechunk (CodeChunk *last, int dynamic, int size)
339 int minsize, flags = CODE_FLAG_MMAP;
340 int chunk_size, bsize = 0;
341 int pagesize, valloc_granule;
346 flags = CODE_FLAG_MALLOC;
349 pagesize = mono_pagesize ();
350 valloc_granule = mono_valloc_granule ();
354 flags = CODE_FLAG_MALLOC;
356 minsize = MAX (pagesize * MIN_PAGES, valloc_granule);
358 chunk_size = minsize;
360 /* Allocate MIN_ALIGN-1 more than we need so we can still */
361 /* guarantee MIN_ALIGN alignment for individual allocs */
362 /* from mono_code_manager_reserve_align. */
363 size += MIN_ALIGN - 1;
364 size &= ~(MIN_ALIGN - 1);
366 chunk_size += valloc_granule - 1;
367 chunk_size &= ~ (valloc_granule - 1);
372 /* Reserve more space since there are no other chunks we might use if this one gets full */
373 bsize = (chunk_size * 2) / BIND_ROOM;
375 bsize = chunk_size / BIND_ROOM;
376 if (bsize < MIN_BSIZE)
378 bsize += MIN_ALIGN -1;
379 bsize &= ~ (MIN_ALIGN - 1);
380 if (chunk_size - size < bsize) {
381 chunk_size = size + bsize;
383 chunk_size += valloc_granule - 1;
384 chunk_size &= ~ (valloc_granule - 1);
389 if (flags == CODE_FLAG_MALLOC) {
390 ptr = dlmemalign (MIN_ALIGN, chunk_size + MIN_ALIGN - 1);
394 /* Try to allocate code chunks next to each other to help the VM */
397 ptr = codechunk_valloc ((guint8*)last->data + last->size, chunk_size);
399 ptr = codechunk_valloc (NULL, chunk_size);
404 if (flags == CODE_FLAG_MALLOC) {
406 /* Make sure the thunks area is zeroed */
407 memset (ptr, 0, bsize);
411 chunk = (CodeChunk *) g_malloc (sizeof (CodeChunk));
413 if (flags == CODE_FLAG_MALLOC)
416 mono_vfree (ptr, chunk_size, MONO_MEM_ACCOUNT_CODE);
420 chunk->size = chunk_size;
421 chunk->data = (char *) ptr;
422 chunk->flags = flags;
424 chunk->bsize = bsize;
425 if (code_manager_callbacks.chunk_new)
426 code_manager_callbacks.chunk_new ((gpointer)chunk->data, chunk->size);
427 mono_profiler_code_chunk_new((gpointer) chunk->data, chunk->size);
429 code_memory_used += chunk_size;
430 mono_runtime_resource_check_limit (MONO_RESOURCE_JIT_CODE, code_memory_used);
431 /*printf ("code chunk at: %p\n", ptr);*/
436 * mono_code_manager_reserve:
437 * @cman: a code manager
438 * @size: size of memory to allocate
439 * @alignment: power of two alignment value
441 * Allocates at least @size bytes of memory inside the code manager @cman.
443 * Returns: the pointer to the allocated memory or #NULL on failure
446 mono_code_manager_reserve_align (MonoCodeManager *cman, int size, int alignment)
448 CodeChunk *chunk, *prev;
450 guint32 align_mask = alignment - 1;
452 g_assert (!cman->read_only);
454 /* eventually allow bigger alignments, but we need to fix the dynamic alloc code to
457 g_assert (alignment <= MIN_ALIGN);
460 ++dynamic_code_alloc_count;
461 dynamic_code_bytes_count += size;
464 if (!cman->current) {
465 cman->current = new_codechunk (cman->last, cman->dynamic, size);
468 cman->last = cman->current;
471 for (chunk = cman->current; chunk; chunk = chunk->next) {
472 if (ALIGN_INT (chunk->pos, alignment) + size <= chunk->size) {
473 chunk->pos = ALIGN_INT (chunk->pos, alignment);
474 /* Align the chunk->data we add to chunk->pos */
475 /* or we can't guarantee proper alignment */
476 ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
477 chunk->pos = ((char*)ptr - chunk->data) + size;
482 * no room found, move one filled chunk to cman->full
483 * to keep cman->current from growing too much
486 for (chunk = cman->current; chunk; prev = chunk, chunk = chunk->next) {
487 if (chunk->pos + MIN_ALIGN * 4 <= chunk->size)
490 prev->next = chunk->next;
492 cman->current = chunk->next;
494 chunk->next = cman->full;
498 chunk = new_codechunk (cman->last, cman->dynamic, size);
501 chunk->next = cman->current;
502 cman->current = chunk;
503 cman->last = cman->current;
504 chunk->pos = ALIGN_INT (chunk->pos, alignment);
505 /* Align the chunk->data we add to chunk->pos */
506 /* or we can't guarantee proper alignment */
507 ptr = (void*)((((uintptr_t)chunk->data + align_mask) & ~(uintptr_t)align_mask) + chunk->pos);
508 chunk->pos = ((char*)ptr - chunk->data) + size;
513 * mono_code_manager_reserve:
514 * @cman: a code manager
515 * @size: size of memory to allocate
517 * Allocates at least @size bytes of memory inside the code manager @cman.
519 * Returns: the pointer to the allocated memory or #NULL on failure
522 mono_code_manager_reserve (MonoCodeManager *cman, int size)
524 return mono_code_manager_reserve_align (cman, size, MIN_ALIGN);
528 * mono_code_manager_commit:
529 * @cman: a code manager
530 * @data: the pointer returned by mono_code_manager_reserve ()
531 * @size: the size requested in the call to mono_code_manager_reserve ()
532 * @newsize: the new size to reserve
534 * If we reserved too much room for a method and we didn't allocate
535 * already from the code manager, we can get back the excess allocation
536 * for later use in the code manager.
539 mono_code_manager_commit (MonoCodeManager *cman, void *data, int size, int newsize)
541 g_assert (newsize <= size);
543 if (cman->current && (size != newsize) && (data == cman->current->data + cman->current->pos - size)) {
544 cman->current->pos -= size - newsize;
549 * mono_code_manager_size:
550 * @cman: a code manager
551 * @used_size: pointer to an integer for the result
553 * This function can be used to get statistics about a code manager:
554 * the integer pointed to by @used_size will contain how much
555 * memory is actually used inside the code managed @cman.
557 * Returns: the amount of memory allocated in @cman
560 mono_code_manager_size (MonoCodeManager *cman, int *used_size)
565 for (chunk = cman->current; chunk; chunk = chunk->next) {
569 for (chunk = cman->full; chunk; chunk = chunk->next) {