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 <stdio.h>
  35 #include "imports.h"
  36 #include "execmem.h"
  37 #include "c11/threads.h"
  38
  39
  40 #if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun) || defined(__HAIKU__)
  41
  42 /*
  43  * Allocate a large block of memory which can hold code then dole it out
  44  * in pieces by means of the generic memory manager code.
  45 */
  46
  47 #include <unistd.h>
  48 #include <sys/mman.h>
  49 #include "mm.h"
  50
  51 #ifdef MESA_SELINUX
  52 #include <selinux/selinux.h>
  53 #endif
  54
  55
  56 #ifndef MAP_ANONYMOUS
  57 #define MAP_ANONYMOUS MAP_ANON
  58 #endif
  59
  60
  61 #define EXEC_HEAP_SIZE (10*1024*1024)
  62
  63 static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
  64
  65 static struct mem_block *exec_heap = NULL;
  66 static unsigned char *exec_mem = NULL;
  67
  68
  69 static int
  70 init_heap(void)
  71 {
  72 #ifdef MESA_SELINUX
  73    if (is_selinux_enabled()) {
  74       if (!security_get_boolean_active("allow_execmem") ||
  75           !security_get_boolean_pending("allow_execmem"))
  76          return 0;
  77    }
  78 #endif
  79
  80    if (!exec_heap)
  81       exec_heap = mmInit( 0, EXEC_HEAP_SIZE );
  82
  83    if (!exec_mem)
  84       exec_mem = mmap(NULL, EXEC_HEAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
  85                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  86
  87    return (exec_mem != MAP_FAILED);
  88 }
  89
  90
  91 void *
  92 _mesa_exec_malloc(GLuint size)
  93 {
  94    struct mem_block *block = NULL;
  95    void *addr = NULL;
  96
  97    mtx_lock(&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       printf("_mesa_exec_malloc failed\n");
 111
 112 bail:
 113    mtx_unlock(&exec_mutex);
 114
 115    return addr;
 116 }
 117
 118
 119 void
 120 _mesa_exec_free(void *addr)
 121 {
 122    mtx_lock(&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    mtx_unlock(&exec_mutex);
 132 }
 133
 134
 135 #else
 136
 137 /*
 138  * Just use regular memory.
 139  */
 140
 141 void *
 142 _mesa_exec_malloc(GLuint size)
 143 {
 144    return malloc( size );
 145 }
 146
 147
 148 void
 149 _mesa_exec_free(void *addr)
 150 {
 151    free(addr);
 152 }
 153
 154
 155 #endif