Home | History | Annotate | Download | only in rtasm 
      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  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
     19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     21  * OTHER DEALINGS IN THE SOFTWARE.
     22  *
     23  **************************************************************************/
     24 
     25 
     26 /**
     27  * \file exemem.c
     28  * Functions for allocating executable memory.
     29  *
     30  * \author Keith Whitwell
     31  */
     32 
     33 
     34 #include "pipe/p_compiler.h"
     35 #include "util/u_debug.h"
     36 #include "os/os_thread.h"
     37 #include "util/u_memory.h"
     38 
     39 #include "rtasm_execmem.h"
     40 
     41 #ifndef MAP_ANONYMOUS
     42 #define MAP_ANONYMOUS MAP_ANON
     43 #endif
     44 
     45 #if defined(PIPE_OS_WINDOWS)
     46 #ifndef WIN32_LEAN_AND_MEAN
     47 #define WIN32_LEAN_AND_MEAN 1
     48 #endif
     49 #include <windows.h>
     50 #endif
     51 
     52 #if defined(PIPE_OS_UNIX)
     53 
     54 
     55 /*
     56  * Allocate a large block of memory which can hold code then dole it out
     57  * in pieces by means of the generic memory manager code.
     58  */
     59 
     60 #include <unistd.h>
     61 #include <sys/mman.h>
     62 #include "util/u_mm.h"
     63 
     64 #define EXEC_HEAP_SIZE (10*1024*1024)
     65 
     66 static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
     67 
     68 static struct mem_block *exec_heap = NULL;
     69 static unsigned char *exec_mem = NULL;
     70 
     71 
     72 static int
     73 init_heap(void)
     74 {
     75    if (!exec_heap)
     76       exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
     77 
     78    if (!exec_mem)
     79       exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE,
     80 					PROT_EXEC | PROT_READ | PROT_WRITE,
     81 					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
     82 
     83    return (exec_mem != MAP_FAILED);
     84 }
     85 
     86 
     87 void *
     88 rtasm_exec_malloc(size_t size)
     89 {
     90    struct mem_block *block = NULL;
     91    void *addr = NULL;
     92 
     93    mtx_lock(&exec_mutex);
     94 
     95    if (!init_heap())
     96       goto bail;
     97 
     98    if (exec_heap) {
     99       size = (size + 31) & ~31;  /* next multiple of 32 bytes */
    100       block = u_mmAllocMem( exec_heap, size, 5, 0 ); /* 5 -> 32-byte alignment */
    101    }
    102 
    103    if (block)
    104       addr = exec_mem + block->ofs;
    105    else
    106       debug_printf("rtasm_exec_malloc failed\n");
    107 
    108 bail:
    109    mtx_unlock(&exec_mutex);
    110 
    111    return addr;
    112 }
    113 
    114 
    115 void
    116 rtasm_exec_free(void *addr)
    117 {
    118    mtx_lock(&exec_mutex);
    119 
    120    if (exec_heap) {
    121       struct mem_block *block = u_mmFindBlock(exec_heap, (unsigned char *)addr - exec_mem);
    122 
    123       if (block)
    124 	 u_mmFreeMem(block);
    125    }
    126 
    127    mtx_unlock(&exec_mutex);
    128 }
    129 
    130 
    131 #elif defined(PIPE_OS_WINDOWS)
    132 
    133 
    134 /*
    135  * Avoid Data Execution Prevention.
    136  */
    137 
    138 void *
    139 rtasm_exec_malloc(size_t size)
    140 {
    141    return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    142 }
    143 
    144 
    145 void
    146 rtasm_exec_free(void *addr)
    147 {
    148    VirtualFree(addr, 0, MEM_RELEASE);
    149 }
    150 
    151 
    152 #else
    153 
    154 
    155 /*
    156  * Just use regular memory.
    157  */
    158 
    159 void *
    160 rtasm_exec_malloc(size_t size)
    161 {
    162    return MALLOC( size );
    163 }
    164 
    165 
    166 void
    167 rtasm_exec_free(void *addr)
    168 {
    169    FREE(addr);
    170 }
    171 
    172 
    173 #endif
    174