osdep/mmap-os2.c

   1 /*
   2  * very simple implementation of mmap() for OS/2
   3  *
   4  * Copyright (c) 2008 KO Myung-Hun (komh@chollian.net)
   5  *
   6  * This file is part of MPlayer.
   7  *
   8  * MPlayer is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * MPlayer is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define INCL_DOS
  24 #include <os2.h>
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <io.h>
  29 #include <sys/types.h>
  30
  31 #include "config.h"
  32 #include "mmap.h"
  33 #include "mmap_anon.h"
  34
  35 typedef struct os2_mmap_s
  36 {
  37     void    *addr;
  38     size_t  len;
  39     int     flags;
  40     struct os2_mmap_s *prev;
  41     struct os2_mmap_s *next;
  42 } os2_mmap;
  43 static os2_mmap *m_mmap = NULL;
  44
  45 void *mmap( void *addr, size_t len, int prot, int flags, int fildes, off_t off )
  46 {
  47     os2_mmap *new_mmap;
  48
  49     ULONG fl;
  50     ULONG rc;
  51
  52     void  *ret;
  53
  54     if( prot & PROT_WRITE )
  55     {
  56         if( flags & MAP_SHARED )
  57             return MAP_FAILED;
  58
  59         if( !( flags & MAP_PRIVATE ))
  60             return MAP_FAILED;
  61     }
  62
  63     if( flags & MAP_FIXED )
  64     {
  65         ULONG cb;
  66
  67         cb = len;
  68         rc = DosQueryMem( addr, &cb, &fl );
  69         if( rc || ( cb < len ))
  70             return MAP_FAILED;
  71
  72         rc = DosSetMem( addr, len, fPERM );
  73         if( rc )
  74             return MAP_FAILED;
  75
  76         ret = addr;
  77     }
  78     else
  79     {
  80         // Allocate tiled memory compatible with 16-bit selectors
  81         // 'fs_seg' in 'ldt_keeper.c' need this attribute
  82         rc = DosAllocMem( &ret, len, fALLOC );
  83         if( rc )
  84             return MAP_FAILED;
  85     }
  86
  87     new_mmap = ( os2_mmap * )malloc( sizeof( os2_mmap ));
  88     new_mmap->addr  = ret;
  89     new_mmap->len   = len;
  90     new_mmap->flags = flags;
  91     new_mmap->prev  = m_mmap;
  92     new_mmap->next  = NULL;
  93
  94     if( m_mmap )
  95         m_mmap->next = new_mmap;
  96     m_mmap = new_mmap;
  97
  98     if( !( flags & MAP_ANON ))
  99     {
 100         int pos;
 101
 102         /* Now read in the file */
 103         if(( pos = lseek( fildes, off, SEEK_SET )) == -1)
 104         {
 105             munmap( ret, len );
 106
 107             return MAP_FAILED;
 108         }
 109
 110         read( fildes, ret, len );
 111         lseek( fildes, pos, SEEK_SET );  /* Restore the file pointer */
 112     }
 113
 114     fl = 0;
 115
 116     if( prot & PROT_READ )
 117         fl |= PAG_READ;
 118
 119     if( prot & PROT_WRITE )
 120         fl |= PAG_WRITE;
 121
 122     if( prot & PROT_EXEC )
 123         fl |= PAG_EXECUTE;
 124
 125     if( prot & PROT_NONE )
 126         fl |= PAG_GUARD;
 127
 128     rc = DosSetMem( ret, len, fl );
 129     if( rc )
 130     {
 131         munmap( ret, len );
 132
 133         return MAP_FAILED;
 134     }
 135
 136     return ret;
 137 }
 138
 139 int munmap( void *addr, size_t len )
 140 {
 141     os2_mmap *mm;
 142
 143     for( mm = m_mmap; mm; mm = mm->prev )
 144     {
 145         if( mm->addr == addr )
 146             break;
 147     }
 148
 149     if( mm )
 150     {
 151
 152         if( !( mm->flags & MAP_FIXED ))
 153             DosFreeMem( addr );
 154
 155         if( mm->next )
 156             mm->next->prev = mm->prev;
 157
 158         if( mm->prev )
 159             mm->prev->next = mm->next;
 160
 161         if( m_mmap == mm )
 162             m_mmap = mm->prev;
 163
 164         free( mm );
 165
 166         return 0;
 167     }
 168
 169     return -1;
 170 }
 171
 172 int mprotect( void *addr, size_t len, int prot )
 173 {
 174     os2_mmap *mm;
 175
 176     for( mm = m_mmap; mm; mm = mm->prev )
 177     {
 178         if( mm->addr == addr )
 179             break;
 180     }
 181
 182     if( mm )
 183     {
 184         ULONG fl;
 185
 186         fl = 0;
 187
 188         if( prot & PROT_READ )
 189             fl |= PAG_READ;
 190
 191         if( prot & PROT_WRITE )
 192             fl |= PAG_WRITE;
 193
 194         if( prot & PROT_EXEC )
 195             fl |= PAG_EXECUTE;
 196
 197         if( prot & PROT_NONE )
 198             fl |= PAG_GUARD;
 199
 200         if( DosSetMem( addr, len, fl ) == 0 )
 201             return 0;
 202     }
 203
 204     return -1;
 205 }
 206
 207 void *mmap_anon( void *addr, size_t len, int prot, int flags, off_t off )
 208 {
 209     return mmap( addr, len, prot, flags | MAP_ANON, -1, off );
 210 }