rtasm_execmem.c revision cdc920a0 
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 "os/os_thread.h"
62#include "util/u_mm.h"
63
64#define EXEC_HEAP_SIZE (10*1024*1024)
65
66pipe_static_mutex(exec_mutex);
67
68static struct mem_block *exec_heap = NULL;
69static unsigned char *exec_mem = NULL;
70
71
72static void
73init_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
84
85void *
86rtasm_exec_malloc(size_t size)
87{
88   struct mem_block *block = NULL;
89   void *addr = NULL;
90
91   pipe_mutex_lock(exec_mutex);
92
93   init_heap();
94
95   if (exec_heap) {
96      size = (size + 31) & ~31;  /* next multiple of 32 bytes */
97      block = u_mmAllocMem( exec_heap, size, 5, 0 ); /* 5 -> 32-byte alignment */
98   }
99
100   if (block)
101      addr = exec_mem + block->ofs;
102   else
103      debug_printf("rtasm_exec_malloc failed\n");
104
105   pipe_mutex_unlock(exec_mutex);
106
107   return addr;
108}
109
110
111void
112rtasm_exec_free(void *addr)
113{
114   pipe_mutex_lock(exec_mutex);
115
116   if (exec_heap) {
117      struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
118
119      if (block)
120	 u_mmFreeMem(block);
121   }
122
123   pipe_mutex_unlock(exec_mutex);
124}
125
126
127#elif defined(PIPE_OS_WINDOWS)
128
129
130/*
131 * Avoid Data Execution Prevention.
132 */
133
134void *
135rtasm_exec_malloc(size_t size)
136{
137   return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
138}
139
140
141void
142rtasm_exec_free(void *addr)
143{
144   VirtualFree(addr, 0, MEM_RELEASE);
145}
146
147
148#else
149
150
151/*
152 * Just use regular memory.
153 */
154
155void *
156rtasm_exec_malloc(size_t size)
157{
158   return MALLOC( size );
159}
160
161
162void
163rtasm_exec_free(void *addr)
164{
165   FREE(addr);
166}
167
168
169#endif
170