src/mesa/main/execmem.c

   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
  61 static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
  62
  63 static struct mem_block *exec_heap = NULL;
  64 static unsigned char *exec_mem = NULL;
  65
  66
  67 static int
  68 init_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
  89 void *
  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
 110 bail:
 111    mtx_unlock(&exec_mutex);
 112
 113    return addr;
 114 }
 115
 116
 117 void
 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
 139 void *
 140 _mesa_exec_malloc(GLuint size)
 141 {
 142    return malloc( size );
 143 }
 144
 145
 146 void
 147 _mesa_exec_free(void *addr)
 148 {
 149    free(addr);
 150 }
 151
 152
 153 #endif