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
66static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
67
68static struct mem_block *exec_heap = NULL;
69static unsigned char *exec_mem = NULL;
70
71
72static int
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(NULL, 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
87void *
88rtasm_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
108bail:
109   mtx_unlock(&exec_mutex);
110
111   return addr;
112}
113
114
115void
116rtasm_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
138void *
139rtasm_exec_malloc(size_t size)
140{
141   return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
142}
143
144
145void
146rtasm_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
159void *
160rtasm_exec_malloc(size_t size)
161{
162   return MALLOC( size );
163}
164
165
166void
167rtasm_exec_free(void *addr)
168{
169   FREE(addr);
170}
171
172
173#endif
174