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      1 /**************************************************************************
      2  *
      3  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining a
      6  * copy of this software and associated documentation files (the "Software"),
      7  * to deal in the Software without restriction, including without limitation
      8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      9  * and/or sell copies of the Software, and to permit persons to whom the
     10  * Software is furnished to do so, subject to the following conditions:
     11  *
     12  * The above copyright notice and this permission notice shall be included
     13  * in all copies or substantial portions of the Software.
     14  *
     15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     18  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     19  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     20  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     21  *
     22  **************************************************************************/
     23 
     24 
     25 /**
     26  * \file exemem.c
     27  * Functions for allocating executable memory.
     28  *
     29  * \author Keith Whitwell
     30  */
     31 
     32 
     33 #include "pipe/p_compiler.h"
     34 #include "util/u_debug.h"
     35 #include "os/os_thread.h"
     36 #include "util/u_memory.h"
     37 
     38 #include "rtasm_execmem.h"
     39 
     40 #if defined(PIPE_OS_BSD)
     41 #define MAP_ANONYMOUS MAP_ANON
     42 #endif
     43 
     44 #if defined(PIPE_OS_WINDOWS)
     45 #ifndef WIN32_LEAN_AND_MEAN
     46 #define WIN32_LEAN_AND_MEAN 1
     47 #endif
     48 #include <windows.h>
     49 #endif
     50 
     51 #if defined(PIPE_OS_LINUX) || defined(PIPE_OS_BSD) || defined(PIPE_OS_SOLARIS)
     52 
     53 
     54 /*
     55  * Allocate a large block of memory which can hold code then dole it out
     56  * in pieces by means of the generic memory manager code.
     57  */
     58 
     59 #include <unistd.h>
     60 #include <sys/mman.h>
     61 #include "util/u_mm.h"
     62 
     63 #define EXEC_HEAP_SIZE (10*1024*1024)
     64 
     65 pipe_static_mutex(exec_mutex);
     66 
     67 static struct mem_block *exec_heap = NULL;
     68 static unsigned char *exec_mem = NULL;
     69 
     70 
     71 static void
     72 init_heap(void)
     73 {
     74    if (!exec_heap)
     75       exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
     76 
     77    if (!exec_mem)
     78       exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
     79 					PROT_EXEC | PROT_READ | PROT_WRITE,
     80 					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
     81 }
     82 
     83 
     84 void *
     85 rtasm_exec_malloc(size_t size)
     86 {
     87    struct mem_block *block = NULL;
     88    void *addr = NULL;
     89 
     90    pipe_mutex_lock(exec_mutex);
     91 
     92    init_heap();
     93 
     94    if (exec_heap) {
     95       size = (size + 31) & ~31;  /* next multiple of 32 bytes */
     96       block = u_mmAllocMem( exec_heap, size, 5, 0 ); /* 5 -> 32-byte alignment */
     97    }
     98 
     99    if (block)
    100       addr = exec_mem + block->ofs;
    101    else
    102       debug_printf("rtasm_exec_malloc failed\n");
    103 
    104    pipe_mutex_unlock(exec_mutex);
    105 
    106    return addr;
    107 }
    108 
    109 
    110 void
    111 rtasm_exec_free(void *addr)
    112 {
    113    pipe_mutex_lock(exec_mutex);
    114 
    115    if (exec_heap) {
    116       struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
    117 
    118       if (block)
    119 	 u_mmFreeMem(block);
    120    }
    121 
    122    pipe_mutex_unlock(exec_mutex);
    123 }
    124 
    125 
    126 #elif defined(PIPE_OS_WINDOWS)
    127 
    128 
    129 /*
    130  * Avoid Data Execution Prevention.
    131  */
    132 
    133 void *
    134 rtasm_exec_malloc(size_t size)
    135 {
    136    return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    137 }
    138 
    139 
    140 void
    141 rtasm_exec_free(void *addr)
    142 {
    143    VirtualFree(addr, 0, MEM_RELEASE);
    144 }
    145 
    146 
    147 #else
    148 
    149 
    150 /*
    151  * Just use regular memory.
    152  */
    153 
    154 void *
    155 rtasm_exec_malloc(size_t size)
    156 {
    157    return MALLOC( size );
    158 }
    159 
    160 
    161 void
    162 rtasm_exec_free(void *addr)
    163 {
    164    FREE(addr);
    165 }
    166 
    167 
    168 #endif
    169