src/mesa/main/execmem.c

   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 execmem.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
  64 static struct mem_block *exec_heap = NULL;
  65 static unsigned char *exec_mem = NULL;
  66
  67
  68 static int
  69 init_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 = mmap(NULL, EXEC_HEAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
  84                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  85
  86    return (exec_mem != MAP_FAILED);
  87 }
  88
  89
  90 void *
  91 _mesa_exec_malloc(GLuint size)
  92 {
  93    struct mem_block *block = NULL;
  94    void *addr = NULL;
  95
  96    _glthread_LOCK_MUTEX(exec_mutex);
  97
  98    if (!init_heap())
  99       goto bail;
 100
 101    if (exec_heap) {
 102       size = (size + 31) & ~31;
 103       block = mmAllocMem( exec_heap, size, 32, 0 );
 104    }
 105
 106    if (block)
 107       addr = exec_mem + block->ofs;
 108    else
 109       _mesa_printf("_mesa_exec_malloc failed\n");
 110
 111 bail:
 112    _glthread_UNLOCK_MUTEX(exec_mutex);
 113
 114    return addr;
 115 }
 116
 117
 118 void
 119 _mesa_exec_free(void *addr)
 120 {
 121    _glthread_LOCK_MUTEX(exec_mutex);
 122
 123    if (exec_heap) {
 124       struct mem_block *block = mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
 125
 126       if (block)
 127          mmFreeMem(block);
 128    }
 129
 130    _glthread_UNLOCK_MUTEX(exec_mutex);
 131 }
 132
 133
 134 #else
 135
 136 /*
 137  * Just use regular memory.
 138  */
 139
 140 void *
 141 _mesa_exec_malloc(GLuint size)
 142 {
 143    return _mesa_malloc( size );
 144 }
 145
 146
 147 void
 148 _mesa_exec_free(void *addr)
 149 {
 150    _mesa_free(addr);
 151 }
 152
 153
 154 #endif