1 /*
2 * Stack-less Just-In-Time compiler
3 *
4 * Copyright Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without modification, are
7 * permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright notice, this list of
10 * conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
13 * of conditions and the following disclaimer in the documentation and/or other materials
14 * provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
19 * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
21 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /* ------------------------------------------------------------------------ */
28 /* Locks */
29 /* ------------------------------------------------------------------------ */
30
31 /* Executable Allocator */
32
33 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) \
34 && !(defined SLJIT_WX_EXECUTABLE_ALLOCATOR && SLJIT_WX_EXECUTABLE_ALLOCATOR)
35 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
36 #define SLJIT_ALLOCATOR_LOCK()
37 #define SLJIT_ALLOCATOR_UNLOCK()
38 #elif !(defined _WIN32)
39 #include <pthread.h>
40
41 static pthread_mutex_t allocator_lock = PTHREAD_MUTEX_INITIALIZER;
42
43 #define SLJIT_ALLOCATOR_LOCK() pthread_mutex_lock(&allocator_lock)
44 #define SLJIT_ALLOCATOR_UNLOCK() pthread_mutex_unlock(&allocator_lock)
45 #else /* windows */
46 static HANDLE allocator_lock;
47
allocator_grab_lock(void)48 static SLJIT_INLINE void allocator_grab_lock(void)
49 {
50 HANDLE lock;
51 if (SLJIT_UNLIKELY(!InterlockedCompareExchangePointer(&allocator_lock, NULL, NULL))) {
52 lock = CreateMutex(NULL, FALSE, NULL);
53 if (InterlockedCompareExchangePointer(&allocator_lock, lock, NULL))
54 CloseHandle(lock);
55 }
56 WaitForSingleObject(allocator_lock, INFINITE);
57 }
58
59 #define SLJIT_ALLOCATOR_LOCK() allocator_grab_lock()
60 #define SLJIT_ALLOCATOR_UNLOCK() ReleaseMutex(allocator_lock)
61 #endif /* thread implementation */
62 #endif /* SLJIT_EXECUTABLE_ALLOCATOR && !SLJIT_WX_EXECUTABLE_ALLOCATOR */
63
64 /* ------------------------------------------------------------------------ */
65 /* Stack */
66 /* ------------------------------------------------------------------------ */
67
68 #if ((defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) \
69 && !(defined SLJIT_UTIL_SIMPLE_STACK_ALLOCATION && SLJIT_UTIL_SIMPLE_STACK_ALLOCATION)) \
70 || ((defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) \
71 && !((defined SLJIT_PROT_EXECUTABLE_ALLOCATOR && SLJIT_PROT_EXECUTABLE_ALLOCATOR) \
72 || (defined SLJIT_WX_EXECUTABLE_ALLOCATOR && SLJIT_WX_EXECUTABLE_ALLOCATOR)))
73
74 #ifndef _WIN32
75 /* Provides mmap function. */
76 #include <sys/types.h>
77 #include <sys/mman.h>
78
79 #ifndef MAP_ANON
80 #ifdef MAP_ANONYMOUS
81 #define MAP_ANON MAP_ANONYMOUS
82 #endif /* MAP_ANONYMOUS */
83 #endif /* !MAP_ANON */
84
85 #ifndef MAP_ANON
86
87 #include <fcntl.h>
88
89 #ifdef O_CLOEXEC
90 #define SLJIT_CLOEXEC O_CLOEXEC
91 #else /* !O_CLOEXEC */
92 #define SLJIT_CLOEXEC 0
93 #endif /* O_CLOEXEC */
94
95 /* Some old systems do not have MAP_ANON. */
96 static int dev_zero = -1;
97
98 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
99
open_dev_zero(void)100 static SLJIT_INLINE int open_dev_zero(void)
101 {
102 dev_zero = open("/dev/zero", O_RDWR | SLJIT_CLOEXEC);
103
104 return dev_zero < 0;
105 }
106
107 #else /* !SLJIT_SINGLE_THREADED */
108
109 #include <pthread.h>
110
111 static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;
112
open_dev_zero(void)113 static SLJIT_INLINE int open_dev_zero(void)
114 {
115 pthread_mutex_lock(&dev_zero_mutex);
116 if (SLJIT_UNLIKELY(dev_zero < 0))
117 dev_zero = open("/dev/zero", O_RDWR | SLJIT_CLOEXEC);
118
119 pthread_mutex_unlock(&dev_zero_mutex);
120 return dev_zero < 0;
121 }
122
123 #endif /* SLJIT_SINGLE_THREADED */
124 #undef SLJIT_CLOEXEC
125 #endif /* !MAP_ANON */
126 #endif /* !_WIN32 */
127 #endif /* open_dev_zero */
128
129 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) \
130 || (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
131
132 #ifdef _WIN32
133
get_page_alignment(void)134 static SLJIT_INLINE sljit_uw get_page_alignment(void) {
135 SYSTEM_INFO si;
136 static sljit_uw sljit_page_align = 0;
137 if (!sljit_page_align) {
138 GetSystemInfo(&si);
139 sljit_page_align = (sljit_uw)si.dwPageSize - 1;
140 }
141 return sljit_page_align;
142 }
143
144 #else
145
146 #include <unistd.h>
147
get_page_alignment(void)148 static SLJIT_INLINE sljit_uw get_page_alignment(void) {
149 static sljit_uw sljit_page_align = 0;
150
151 sljit_sw align;
152
153 if (!sljit_page_align) {
154 #ifdef _SC_PAGESIZE
155 align = sysconf(_SC_PAGESIZE);
156 #else
157 align = getpagesize();
158 #endif
159 /* Should never happen. */
160 if (align < 0)
161 align = 4096;
162 sljit_page_align = (sljit_uw)align - 1;
163 }
164 return sljit_page_align;
165 }
166
167 #endif /* _WIN32 */
168
169 #endif /* get_page_alignment() */
170
171 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK)
172
173 #if (defined SLJIT_UTIL_SIMPLE_STACK_ALLOCATION && SLJIT_UTIL_SIMPLE_STACK_ALLOCATION)
174
sljit_allocate_stack(sljit_uw start_size,sljit_uw max_size,void * allocator_data)175 SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_FUNC sljit_allocate_stack(sljit_uw start_size, sljit_uw max_size, void *allocator_data)
176 {
177 struct sljit_stack *stack;
178 void *ptr;
179
180 SLJIT_UNUSED_ARG(allocator_data);
181
182 if (start_size > max_size || start_size < 1)
183 return NULL;
184
185 stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack), allocator_data);
186 if (stack == NULL)
187 return NULL;
188
189 ptr = SLJIT_MALLOC(max_size, allocator_data);
190 if (ptr == NULL) {
191 SLJIT_FREE(stack, allocator_data);
192 return NULL;
193 }
194
195 stack->min_start = (sljit_u8 *)ptr;
196 stack->end = stack->min_start + max_size;
197 stack->start = stack->end - start_size;
198 stack->top = stack->end;
199 return stack;
200 }
201
sljit_free_stack(struct sljit_stack * stack,void * allocator_data)202 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
203 {
204 SLJIT_UNUSED_ARG(allocator_data);
205 SLJIT_FREE((void*)stack->min_start, allocator_data);
206 SLJIT_FREE(stack, allocator_data);
207 }
208
sljit_stack_resize(struct sljit_stack * stack,sljit_u8 * new_start)209 SLJIT_API_FUNC_ATTRIBUTE sljit_u8 *SLJIT_FUNC sljit_stack_resize(struct sljit_stack *stack, sljit_u8 *new_start)
210 {
211 if ((new_start < stack->min_start) || (new_start >= stack->end))
212 return NULL;
213 stack->start = new_start;
214 return new_start;
215 }
216
217 #else /* !SLJIT_UTIL_SIMPLE_STACK_ALLOCATION */
218
219 #ifdef _WIN32
220
sljit_free_stack(struct sljit_stack * stack,void * allocator_data)221 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
222 {
223 SLJIT_UNUSED_ARG(allocator_data);
224 VirtualFree((void*)stack->min_start, 0, MEM_RELEASE);
225 SLJIT_FREE(stack, allocator_data);
226 }
227
228 #else /* !_WIN32 */
229
sljit_free_stack(struct sljit_stack * stack,void * allocator_data)230 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
231 {
232 SLJIT_UNUSED_ARG(allocator_data);
233 munmap((void*)stack->min_start, (size_t)(stack->end - stack->min_start));
234 SLJIT_FREE(stack, allocator_data);
235 }
236
237 #endif /* _WIN32 */
238
sljit_allocate_stack(sljit_uw start_size,sljit_uw max_size,void * allocator_data)239 SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_FUNC sljit_allocate_stack(sljit_uw start_size, sljit_uw max_size, void *allocator_data)
240 {
241 struct sljit_stack *stack;
242 void *ptr;
243 sljit_uw page_align;
244
245 SLJIT_UNUSED_ARG(allocator_data);
246
247 if (start_size > max_size || start_size < 1)
248 return NULL;
249
250 stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack), allocator_data);
251 if (stack == NULL)
252 return NULL;
253
254 /* Align max_size. */
255 page_align = get_page_alignment();
256 max_size = (max_size + page_align) & ~page_align;
257
258 #ifdef _WIN32
259 ptr = VirtualAlloc(NULL, max_size, MEM_RESERVE, PAGE_READWRITE);
260 if (!ptr) {
261 SLJIT_FREE(stack, allocator_data);
262 return NULL;
263 }
264
265 stack->min_start = (sljit_u8 *)ptr;
266 stack->end = stack->min_start + max_size;
267 stack->start = stack->end;
268
269 if (sljit_stack_resize(stack, stack->end - start_size) == NULL) {
270 sljit_free_stack(stack, allocator_data);
271 return NULL;
272 }
273 #else /* !_WIN32 */
274 #ifdef MAP_ANON
275 ptr = mmap(NULL, max_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
276 #else /* !MAP_ANON */
277 if (SLJIT_UNLIKELY((dev_zero < 0) && open_dev_zero())) {
278 SLJIT_FREE(stack, allocator_data);
279 return NULL;
280 }
281 ptr = mmap(NULL, max_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, dev_zero, 0);
282 #endif /* MAP_ANON */
283 if (ptr == MAP_FAILED) {
284 SLJIT_FREE(stack, allocator_data);
285 return NULL;
286 }
287 stack->min_start = (sljit_u8 *)ptr;
288 stack->end = stack->min_start + max_size;
289 stack->start = stack->end - start_size;
290 #endif /* _WIN32 */
291
292 stack->top = stack->end;
293 return stack;
294 }
295
sljit_stack_resize(struct sljit_stack * stack,sljit_u8 * new_start)296 SLJIT_API_FUNC_ATTRIBUTE sljit_u8 *SLJIT_FUNC sljit_stack_resize(struct sljit_stack *stack, sljit_u8 *new_start)
297 {
298 #if defined _WIN32 || defined(POSIX_MADV_DONTNEED)
299 sljit_uw aligned_old_start;
300 sljit_uw aligned_new_start;
301 sljit_uw page_align;
302 #endif
303
304 if ((new_start < stack->min_start) || (new_start >= stack->end))
305 return NULL;
306
307 #ifdef _WIN32
308 page_align = get_page_alignment();
309
310 aligned_new_start = (sljit_uw)new_start & ~page_align;
311 aligned_old_start = ((sljit_uw)stack->start) & ~page_align;
312 if (aligned_new_start != aligned_old_start) {
313 if (aligned_new_start < aligned_old_start) {
314 if (!VirtualAlloc((void*)aligned_new_start, aligned_old_start - aligned_new_start, MEM_COMMIT, PAGE_READWRITE))
315 return NULL;
316 }
317 else {
318 if (!VirtualFree((void*)aligned_old_start, aligned_new_start - aligned_old_start, MEM_DECOMMIT))
319 return NULL;
320 }
321 }
322 #elif defined(POSIX_MADV_DONTNEED)
323 if (stack->start < new_start) {
324 page_align = get_page_alignment();
325
326 aligned_new_start = (sljit_uw)new_start & ~page_align;
327 aligned_old_start = ((sljit_uw)stack->start) & ~page_align;
328
329 if (aligned_new_start > aligned_old_start) {
330 posix_madvise((void*)aligned_old_start, aligned_new_start - aligned_old_start, POSIX_MADV_DONTNEED);
331 #ifdef MADV_FREE
332 madvise((void*)aligned_old_start, aligned_new_start - aligned_old_start, MADV_FREE);
333 #endif /* MADV_FREE */
334 }
335 }
336 #endif /* _WIN32 */
337
338 stack->start = new_start;
339 return new_start;
340 }
341
342 #endif /* SLJIT_UTIL_SIMPLE_STACK_ALLOCATION */
343
344 #endif /* SLJIT_UTIL_STACK */
345
