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 <unistd.h>
  30 #include <sys/types.h>
  31
  32 #include "config.h"
  33 #include "mmap.h"
  34 #include "mmap_anon.h"
  35
  36 typedef struct os2_mmap_s
  37 {
  38     void    *addr;
  39     size_t  len;
  40     int     flags;
  41     struct os2_mmap_s *prev;
  42     struct os2_mmap_s *next;
  43 } os2_mmap;
  44 static os2_mmap *m_mmap = NULL;
  45
  46 void *mmap( void *addr, size_t len, int prot, int flags, int fildes, off_t off )
  47 {
  48     os2_mmap *new_mmap;
  49
  50     ULONG fl;
  51     ULONG rc;
  52
  53     void  *ret;
  54
  55     if( prot & PROT_WRITE )
  56     {
  57         if( flags & MAP_SHARED )
  58             return MAP_FAILED;
  59
  60         if( !( flags & MAP_PRIVATE ))
  61             return MAP_FAILED;
  62     }
  63
  64     if( flags & MAP_FIXED )
  65     {
  66         ULONG cb;
  67
  68         cb = len;
  69         rc = DosQueryMem( addr, &cb, &fl );
  70         if( rc || ( cb < len ))
  71             return MAP_FAILED;
  72
  73         rc = DosSetMem( addr, len, fPERM );
  74         if( rc )
  75             return MAP_FAILED;
  76
  77         ret = addr;
  78     }
  79     else
  80     {
  81         // Allocate tiled memory compatible with 16-bit selectors
  82         // 'fs_seg' in 'ldt_keeper.c' need this attribute
  83         rc = DosAllocMem( &ret, len, fALLOC );
  84         if( rc )
  85             return MAP_FAILED;
  86     }
  87
  88     new_mmap = malloc( sizeof( os2_mmap ));
  89     new_mmap->addr  = ret;
  90     new_mmap->len   = len;
  91     new_mmap->flags = flags;
  92     new_mmap->prev  = m_mmap;
  93     new_mmap->next  = NULL;
  94
  95     if( m_mmap )
  96         m_mmap->next = new_mmap;
  97     m_mmap = new_mmap;
  98
  99     if( !( flags & MAP_ANON ))
 100     {
 101         int pos;
 102
 103         /* Now read in the file */
 104         if(( pos = lseek( fildes, off, SEEK_SET )) == -1)
 105         {
 106             munmap( ret, len );
 107
 108             return MAP_FAILED;
 109         }
 110
 111         read( fildes, ret, len );
 112         lseek( fildes, pos, SEEK_SET );  /* Restore the file pointer */
 113     }
 114
 115     fl = 0;
 116
 117     if( prot & PROT_READ )
 118         fl |= PAG_READ;
 119
 120     if( prot & PROT_WRITE )
 121         fl |= PAG_WRITE;
 122
 123     if( prot & PROT_EXEC )
 124         fl |= PAG_EXECUTE;
 125
 126     if( prot & PROT_NONE )
 127         fl |= PAG_GUARD;
 128
 129     rc = DosSetMem( ret, len, fl );
 130     if( rc )
 131     {
 132         munmap( ret, len );
 133
 134         return MAP_FAILED;
 135     }
 136
 137     return ret;
 138 }
 139
 140 int munmap( void *addr, size_t len )
 141 {
 142     os2_mmap *mm;
 143
 144     for( mm = m_mmap; mm; mm = mm->prev )
 145     {
 146         if( mm->addr == addr )
 147             break;
 148     }
 149
 150     if( mm )
 151     {
 152
 153         if( !( mm->flags & MAP_FIXED ))
 154             DosFreeMem( addr );
 155
 156         if( mm->next )
 157             mm->next->prev = mm->prev;
 158
 159         if( mm->prev )
 160             mm->prev->next = mm->next;
 161
 162         if( m_mmap == mm )
 163             m_mmap = mm->prev;
 164
 165         free( mm );
 166
 167         return 0;
 168     }
 169
 170     return -1;
 171 }
 172
 173 int mprotect( void *addr, size_t len, int prot )
 174 {
 175     os2_mmap *mm;
 176
 177     for( mm = m_mmap; mm; mm = mm->prev )
 178     {
 179         if( mm->addr == addr )
 180             break;
 181     }
 182
 183     if( mm )
 184     {
 185         ULONG fl;
 186
 187         fl = 0;
 188
 189         if( prot & PROT_READ )
 190             fl |= PAG_READ;
 191
 192         if( prot & PROT_WRITE )
 193             fl |= PAG_WRITE;
 194
 195         if( prot & PROT_EXEC )
 196             fl |= PAG_EXECUTE;
 197
 198         if( prot & PROT_NONE )
 199             fl |= PAG_GUARD;
 200
 201         if( DosSetMem( addr, len, fl ) == 0 )
 202             return 0;
 203     }
 204
 205     return -1;
 206 }
 207
 208 void *mmap_anon( void *addr, size_t len, int prot, int flags, off_t off )
 209 {
 210     return mmap( addr, len, prot, flags | MAP_ANON, -1, off );
 211 }