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 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__)
  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 #define EXEC_HEAP_SIZE (10*1024*1024)
  55
  56 _glthread_DECLARE_STATIC_MUTEX(exec_mutex);
  57
  58 static struct mem_block *exec_heap = NULL;
  59 static unsigned char *exec_mem = NULL;
  60
  61
  62 static int
  63 init_heap(void)
  64 {
  65 #ifdef MESA_SELINUX
  66    if (is_selinux_enabled()) {
  67       if (!security_get_boolean_active("allow_execmem") ||
  68           !security_get_boolean_pending("allow_execmem"))
  69          return 0;
  70    }
  71 #endif
  72
  73    if (!exec_heap)
  74       exec_heap = mmInit( 0, EXEC_HEAP_SIZE );
  75
  76    if (!exec_mem)
  77       exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
  78                                         PROT_EXEC | PROT_READ | PROT_WRITE,
  79                                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  80
  81    return (exec_mem != NULL);
  82 }
  83
  84
  85 void *
  86 _mesa_exec_malloc(GLuint size)
  87 {
  88    struct mem_block *block = NULL;
  89    void *addr = NULL;
  90
  91    _glthread_LOCK_MUTEX(exec_mutex);
  92
  93    if (!init_heap())
  94       goto bail;
  95
  96    if (exec_heap) {
  97       size = (size + 31) & ~31;
  98       block = mmAllocMem( exec_heap, size, 32, 0 );
  99    }
 100
 101    if (block)
 102       addr = exec_mem + block->ofs;
 103    else
 104       _mesa_printf("_mesa_exec_malloc failed\n");
 105
 106 bail:
 107    _glthread_UNLOCK_MUTEX(exec_mutex);
 108
 109    return addr;
 110 }
 111
 112
 113 void
 114 _mesa_exec_free(void *addr)
 115 {
 116    _glthread_LOCK_MUTEX(exec_mutex);
 117
 118    if (exec_heap) {
 119       struct mem_block *block = mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
 120
 121       if (block)
 122          mmFreeMem(block);
 123    }
 124
 125    _glthread_UNLOCK_MUTEX(exec_mutex);
 126 }
 127
 128
 129 #else
 130
 131 /*
 132  * Just use regular memory.
 133  */
 134
 135 void *
 136 _mesa_exec_malloc(GLuint size)
 137 {
 138    return _mesa_malloc( size );
 139 }
 140
 141
 142 void
 143 _mesa_exec_free(void *addr)
 144 {
 145    _mesa_free(addr);
 146 }
 147
 148
 149 #endif