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 "util/imports.h"
  36 #include "main/glheader.h"
  37 #include "execmem.h"
  38 #include "c11/threads.h"
  39
  40
  41 #if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun) || defined(__HAIKU__)
  42
  43 /*
  44  * Allocate a large block of memory which can hold code then dole it out
  45  * in pieces by means of the generic memory manager code.
  46 */
  47
  48 #include <unistd.h>
  49 #include <sys/mman.h>
  50 #include "util/u_mm.h"
  51
  52 #ifdef MESA_SELINUX
  53 #include <selinux/selinux.h>
  54 #endif
  55
  56
  57 #ifndef MAP_ANONYMOUS
  58 #define MAP_ANONYMOUS MAP_ANON
  59 #endif
  60
  61
  62 #define EXEC_HEAP_SIZE (10*1024*1024)
  63
  64 static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
  65
  66 static struct mem_block *exec_heap = NULL;
  67 static unsigned char *exec_mem = NULL;
  68
  69
  70 static int
  71 init_heap(void)
  72 {
  73 #ifdef MESA_SELINUX
  74    if (is_selinux_enabled()) {
  75       if (!security_get_boolean_active("allow_execmem") ||
  76           !security_get_boolean_pending("allow_execmem"))
  77          return 0;
  78    }
  79 #endif
  80
  81    if (!exec_heap)
  82       exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
  83
  84    if (!exec_mem)
  85       exec_mem = mmap(NULL, EXEC_HEAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
  86                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  87
  88    return (exec_mem != MAP_FAILED);
  89 }
  90
  91
  92 void *
  93 _mesa_exec_malloc(unsigned size)
  94 {
  95    struct mem_block *block = NULL;
  96    void *addr = NULL;
  97
  98    mtx_lock(&exec_mutex);
  99
 100    if (!init_heap())
 101       goto bail;
 102
 103    if (exec_heap) {
 104       size = (size + 31) & ~31;
 105       block = u_mmAllocMem(exec_heap, size, 5, 0);
 106    }
 107
 108    if (block)
 109       addr = exec_mem + block->ofs;
 110    else
 111       printf("_mesa_exec_malloc failed\n");
 112
 113 bail:
 114    mtx_unlock(&exec_mutex);
 115
 116    return addr;
 117 }
 118
 119
 120 void
 121 _mesa_exec_free(void *addr)
 122 {
 123    mtx_lock(&exec_mutex);
 124
 125    if (exec_heap) {
 126       struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
 127
 128       if (block)
 129          u_mmFreeMem(block);
 130    }
 131
 132    mtx_unlock(&exec_mutex);
 133 }
 134
 135
 136 #else
 137
 138 /*
 139  * Just use regular memory.
 140  */
 141
 142 void *
 143 _mesa_exec_malloc(unsigned size)
 144 {
 145    return malloc( size );
 146 }
 147
 148
 149 void
 150 _mesa_exec_free(void *addr)
 151 {
 152    free(addr);
 153 }
 154
 155
 156 #endif