1 /**************************************************************************
2 *
3 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included
13 * in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 * OTHER DEALINGS IN THE SOFTWARE.
22 *
23 **************************************************************************/
24
25
26 /**
27 * \file exemem.c
28 * Functions for allocating executable memory.
29 *
30 * \author Keith Whitwell
31 */
32
33
34 #include "pipe/p_compiler.h"
35 #include "util/u_debug.h"
36 #include "os/os_thread.h"
37 #include "util/u_memory.h"
38
39 #include "rtasm_execmem.h"
40
41 #ifndef MAP_ANONYMOUS
42 #define MAP_ANONYMOUS MAP_ANON
43 #endif
44
45 #if defined(PIPE_OS_WINDOWS)
46 #ifndef WIN32_LEAN_AND_MEAN
47 #define WIN32_LEAN_AND_MEAN 1
48 #endif
49 #include <windows.h>
50 #endif
51
52 #if defined(PIPE_OS_UNIX)
53
54
55 /*
56 * Allocate a large block of memory which can hold code then dole it out
57 * in pieces by means of the generic memory manager code.
58 */
59
60 #include <unistd.h>
61 #include <sys/mman.h>
62 #include "util/u_mm.h"
63
64 #define EXEC_HEAP_SIZE (10*1024*1024)
65
66 static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
67
68 static struct mem_block *exec_heap = NULL;
69 static unsigned char *exec_mem = NULL;
70
71
72 static int
init_heap(void)73 init_heap(void)
74 {
75 if (!exec_heap)
76 exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
77
78 if (!exec_mem)
79 exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
80 PROT_EXEC | PROT_READ | PROT_WRITE,
81 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
82
83 return (exec_mem != MAP_FAILED);
84 }
85
86
87 void *
rtasm_exec_malloc(size_t size)88 rtasm_exec_malloc(size_t size)
89 {
90 struct mem_block *block = NULL;
91 void *addr = NULL;
92
93 mtx_lock(&exec_mutex);
94
95 if (!init_heap())
96 goto bail;
97
98 if (exec_heap) {
99 size = (size + 31) & ~31; /* next multiple of 32 bytes */
100 block = u_mmAllocMem( exec_heap, size, 5, 0 ); /* 5 -> 32-byte alignment */
101 }
102
103 if (block)
104 addr = exec_mem + block->ofs;
105 else
106 debug_printf("rtasm_exec_malloc failed\n");
107
108 bail:
109 mtx_unlock(&exec_mutex);
110
111 return addr;
112 }
113
114
115 void
rtasm_exec_free(void * addr)116 rtasm_exec_free(void *addr)
117 {
118 mtx_lock(&exec_mutex);
119
120 if (exec_heap) {
121 struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
122
123 if (block)
124 u_mmFreeMem(block);
125 }
126
127 mtx_unlock(&exec_mutex);
128 }
129
130
131 #elif defined(PIPE_OS_WINDOWS)
132
133
134 /*
135 * Avoid Data Execution Prevention.
136 */
137
138 void *
rtasm_exec_malloc(size_t size)139 rtasm_exec_malloc(size_t size)
140 {
141 return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
142 }
143
144
145 void
rtasm_exec_free(void * addr)146 rtasm_exec_free(void *addr)
147 {
148 VirtualFree(addr, 0, MEM_RELEASE);
149 }
150
151
152 #else
153
154
155 /*
156 * Just use regular memory.
157 */
158
159 void *
rtasm_exec_malloc(size_t size)160 rtasm_exec_malloc(size_t size)
161 {
162 return MALLOC( size );
163 }
164
165
166 void
rtasm_exec_free(void * addr)167 rtasm_exec_free(void *addr)
168 {
169 FREE(addr);
170 }
171
172
173 #endif
174