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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   * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
19   * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21   *
22   **************************************************************************/
23  
24  
25  /**
26   * \file exemem.c
27   * Functions for allocating executable memory.
28   *
29   * \author Keith Whitwell
30   */
31  
32  
33  #include "pipe/p_compiler.h"
34  #include "util/u_debug.h"
35  #include "os/os_thread.h"
36  #include "util/u_memory.h"
37  
38  #include "rtasm_execmem.h"
39  
40  #if defined(PIPE_OS_BSD)
41  #define MAP_ANONYMOUS MAP_ANON
42  #endif
43  
44  #if defined(PIPE_OS_WINDOWS)
45  #ifndef WIN32_LEAN_AND_MEAN
46  #define WIN32_LEAN_AND_MEAN 1
47  #endif
48  #include <windows.h>
49  #endif
50  
51  #if defined(PIPE_OS_LINUX) || defined(PIPE_OS_BSD) || defined(PIPE_OS_SOLARIS)
52  
53  
54  /*
55   * Allocate a large block of memory which can hold code then dole it out
56   * in pieces by means of the generic memory manager code.
57   */
58  
59  #include <unistd.h>
60  #include <sys/mman.h>
61  #include "util/u_mm.h"
62  
63  #define EXEC_HEAP_SIZE (10*1024*1024)
64  
65  pipe_static_mutex(exec_mutex);
66  
67  static struct mem_block *exec_heap = NULL;
68  static unsigned char *exec_mem = NULL;
69  
70  
71  static void
init_heap(void)72  init_heap(void)
73  {
74     if (!exec_heap)
75        exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
76  
77     if (!exec_mem)
78        exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
79  					PROT_EXEC | PROT_READ | PROT_WRITE,
80  					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
81  }
82  
83  
84  void *
rtasm_exec_malloc(size_t size)85  rtasm_exec_malloc(size_t size)
86  {
87     struct mem_block *block = NULL;
88     void *addr = NULL;
89  
90     pipe_mutex_lock(exec_mutex);
91  
92     init_heap();
93  
94     if (exec_heap) {
95        size = (size + 31) & ~31;  /* next multiple of 32 bytes */
96        block = u_mmAllocMem( exec_heap, size, 5, 0 ); /* 5 -> 32-byte alignment */
97     }
98  
99     if (block)
100        addr = exec_mem + block->ofs;
101     else
102        debug_printf("rtasm_exec_malloc failed\n");
103  
104     pipe_mutex_unlock(exec_mutex);
105  
106     return addr;
107  }
108  
109  
110  void
rtasm_exec_free(void * addr)111  rtasm_exec_free(void *addr)
112  {
113     pipe_mutex_lock(exec_mutex);
114  
115     if (exec_heap) {
116        struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
117  
118        if (block)
119  	 u_mmFreeMem(block);
120     }
121  
122     pipe_mutex_unlock(exec_mutex);
123  }
124  
125  
126  #elif defined(PIPE_OS_WINDOWS)
127  
128  
129  /*
130   * Avoid Data Execution Prevention.
131   */
132  
133  void *
rtasm_exec_malloc(size_t size)134  rtasm_exec_malloc(size_t size)
135  {
136     return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
137  }
138  
139  
140  void
rtasm_exec_free(void * addr)141  rtasm_exec_free(void *addr)
142  {
143     VirtualFree(addr, 0, MEM_RELEASE);
144  }
145  
146  
147  #else
148  
149  
150  /*
151   * Just use regular memory.
152   */
153  
154  void *
rtasm_exec_malloc(size_t size)155  rtasm_exec_malloc(size_t size)
156  {
157     return MALLOC( size );
158  }
159  
160  
161  void
rtasm_exec_free(void * addr)162  rtasm_exec_free(void *addr)
163  {
164     FREE(addr);
165  }
166  
167  
168  #endif
169