execmem.c revision af69d88d 
1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26/**
27 * \file execmem.c
28 * Functions for allocating executable memory.
29 *
30 * \author Keith Whitwell
31 */
32
33
34#include "imports.h"
35
36
37
38#if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun) || defined(__HAIKU__)
39
40/*
41 * Allocate a large block of memory which can hold code then dole it out
42 * in pieces by means of the generic memory manager code.
43*/
44
45#include <unistd.h>
46#include <sys/mman.h>
47#include "mm.h"
48
49#ifdef MESA_SELINUX
50#include <selinux/selinux.h>
51#endif
52
53
54#ifndef MAP_ANONYMOUS
55#define MAP_ANONYMOUS MAP_ANON
56#endif
57
58
59#define EXEC_HEAP_SIZE (10*1024*1024)
60
61static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
62
63static struct mem_block *exec_heap = NULL;
64static unsigned char *exec_mem = NULL;
65
66
67static int
68init_heap(void)
69{
70#ifdef MESA_SELINUX
71   if (is_selinux_enabled()) {
72      if (!security_get_boolean_active("allow_execmem") ||
73	  !security_get_boolean_pending("allow_execmem"))
74         return 0;
75   }
76#endif
77
78   if (!exec_heap)
79      exec_heap = mmInit( 0, EXEC_HEAP_SIZE );
80
81   if (!exec_mem)
82      exec_mem = mmap(NULL, EXEC_HEAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
83		      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
84
85   return (exec_mem != MAP_FAILED);
86}
87
88
89void *
90_mesa_exec_malloc(GLuint size)
91{
92   struct mem_block *block = NULL;
93   void *addr = NULL;
94
95   mtx_lock(&exec_mutex);
96
97   if (!init_heap())
98      goto bail;
99
100   if (exec_heap) {
101      size = (size + 31) & ~31;
102      block = mmAllocMem( exec_heap, size, 32, 0 );
103   }
104
105   if (block)
106      addr = exec_mem + block->ofs;
107   else
108      printf("_mesa_exec_malloc failed\n");
109
110bail:
111   mtx_unlock(&exec_mutex);
112
113   return addr;
114}
115
116
117void
118_mesa_exec_free(void *addr)
119{
120   mtx_lock(&exec_mutex);
121
122   if (exec_heap) {
123      struct mem_block *block = mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
124
125      if (block)
126	 mmFreeMem(block);
127   }
128
129   mtx_unlock(&exec_mutex);
130}
131
132
133#else
134
135/*
136 * Just use regular memory.
137 */
138
139void *
140_mesa_exec_malloc(GLuint size)
141{
142   return malloc( size );
143}
144
145
146void
147_mesa_exec_free(void *addr)
148{
149   free(addr);
150}
151
152
153#endif
154