xref: /PHP-8.3/ext/pcre/pcre2lib/sljit/sljitUtils.c (revision 32cceb75)
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