execmem.c revision c1f859d4 
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5
4 *
5 * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26/**
27 * \file exemem.c
28 * Functions for allocating executable memory.
29 *
30 * \author Keith Whitwell
31 */
32
33
34#include "imports.h"
35#include "glapi/glthread.h"
36
37
38
39#if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun)
40
41/*
42 * Allocate a large block of memory which can hold code then dole it out
43 * in pieces by means of the generic memory manager code.
44*/
45
46#include <unistd.h>
47#include <sys/mman.h>
48#include "mm.h"
49
50#ifdef MESA_SELINUX
51#include <selinux/selinux.h>
52#endif
53
54
55#ifndef MAP_ANONYMOUS
56#define MAP_ANONYMOUS MAP_ANON
57#endif
58
59
60#define EXEC_HEAP_SIZE (10*1024*1024)
61
62_glthread_DECLARE_STATIC_MUTEX(exec_mutex);
63
64static struct mem_block *exec_heap = NULL;
65static unsigned char *exec_mem = NULL;
66
67
68static int
69init_heap(void)
70{
71#ifdef MESA_SELINUX
72   if (is_selinux_enabled()) {
73      if (!security_get_boolean_active("allow_execmem") ||
74	  !security_get_boolean_pending("allow_execmem"))
75         return 0;
76   }
77#endif
78
79   if (!exec_heap)
80      exec_heap = mmInit( 0, EXEC_HEAP_SIZE );
81
82   if (!exec_mem)
83      exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
84					PROT_EXEC | PROT_READ | PROT_WRITE,
85					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
86
87   return (exec_mem != NULL);
88}
89
90
91void *
92_mesa_exec_malloc(GLuint size)
93{
94   struct mem_block *block = NULL;
95   void *addr = NULL;
96
97   _glthread_LOCK_MUTEX(exec_mutex);
98
99   if (!init_heap())
100      goto bail;
101
102   if (exec_heap) {
103      size = (size + 31) & ~31;
104      block = mmAllocMem( exec_heap, size, 32, 0 );
105   }
106
107   if (block)
108      addr = exec_mem + block->ofs;
109   else
110      _mesa_printf("_mesa_exec_malloc failed\n");
111
112bail:
113   _glthread_UNLOCK_MUTEX(exec_mutex);
114
115   return addr;
116}
117
118
119void
120_mesa_exec_free(void *addr)
121{
122   _glthread_LOCK_MUTEX(exec_mutex);
123
124   if (exec_heap) {
125      struct mem_block *block = mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
126
127      if (block)
128	 mmFreeMem(block);
129   }
130
131   _glthread_UNLOCK_MUTEX(exec_mutex);
132}
133
134
135#else
136
137/*
138 * Just use regular memory.
139 */
140
141void *
142_mesa_exec_malloc(GLuint size)
143{
144   return _mesa_malloc( size );
145}
146
147
148void
149_mesa_exec_free(void *addr)
150{
151   _mesa_free(addr);
152}
153
154
155#endif
156