server/mapping.c

   1 /*
   2  * Server-side file mapping management
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11
  12 #include "config.h"
  13 #include "winnt.h"
  14 #include "winbase.h"
  15
  16 #include "handle.h"
  17 #include "thread.h"
  18 #include "request.h"
  19
  20 struct mapping
  21 {
  22     struct object  obj;             /* object header */
  23     int            size_high;       /* mapping size */
  24     int            size_low;        /* mapping size */
  25     int            protect;         /* protection flags */
  26     struct file   *file;            /* file mapped */
  27 };
  28
  29 static void mapping_dump( struct object *obj, int verbose );
  30 static void mapping_destroy( struct object *obj );
  31
  32 static const struct object_ops mapping_ops =
  33 {
  34     sizeof(struct mapping),      /* size */
  35     mapping_dump,                /* dump */
  36     no_add_queue,                /* add_queue */
  37     NULL,                        /* remove_queue */
  38     NULL,                        /* signaled */
  39     NULL,                        /* satisfied */
  40     NULL,                        /* get_poll_events */
  41     NULL,                        /* poll_event */
  42     no_read_fd,                  /* get_read_fd */
  43     no_write_fd,                 /* get_write_fd */
  44     no_flush,                    /* flush */
  45     no_get_file_info,            /* get_file_info */
  46     mapping_destroy              /* destroy */
  47 };
  48
  49 #ifdef __i386__
  50
  51 /* These are always the same on an i386, and it will be faster this way */
  52 # define page_mask  0xfff
  53 # define page_shift 12
  54 # define init_page_size() /* nothing */
  55
  56 #else  /* __i386__ */
  57
  58 static int page_shift, page_mask;
  59
  60 static void init_page_size(void)
  61 {
  62     int page_size;
  63 # ifdef HAVE_GETPAGESIZE
  64     page_size = getpagesize();
  65 # else
  66 #  ifdef __svr4__
  67     page_size = sysconf(_SC_PAGESIZE);
  68 #  else
  69 #   error Cannot get the page size on this platform
  70 #  endif
  71 # endif
  72     page_mask = page_size - 1;
  73     /* Make sure we have a power of 2 */
  74     assert( !(page_size & page_mask) );
  75     page_shift = 0;
  76     while ((1 << page_shift) != page_size) page_shift++;
  77 }
  78 #endif  /* __i386__ */
  79
  80 #define ROUND_ADDR(addr) \
  81    ((int)(addr) & ~page_mask)
  82
  83 #define ROUND_SIZE(addr,size) \
  84    (((int)(size) + ((int)(addr) & page_mask) + page_mask) & ~page_mask)
  85
  86
  87 static struct object *create_mapping( int size_high, int size_low, int protect,
  88                                       int handle, const WCHAR *name, size_t len )
  89 {
  90     struct mapping *mapping;
  91     int access = 0;
  92
  93     if (!page_mask) init_page_size();
  94
  95     if (!(mapping = create_named_object( &mapping_ops, name, len )))
  96         return NULL;
  97     if (get_error() == STATUS_OBJECT_NAME_COLLISION)
  98         return &mapping->obj;  /* Nothing else to do */
  99
 100     if (protect & VPROT_READ) access |= GENERIC_READ;
 101     if (protect & VPROT_WRITE) access |= GENERIC_WRITE;
 102
 103     if (handle != -1)
 104     {
 105         if (!(mapping->file = get_file_obj( current->process, handle, access ))) goto error;
 106         if (!size_high && !size_low)
 107         {
 108             struct get_file_info_request req;
 109             struct object *obj = (struct object *)mapping->file;
 110             obj->ops->get_file_info( obj, &req );
 111             size_high = req.size_high;
 112             size_low  = ROUND_SIZE( 0, req.size_low );
 113         }
 114         else if (!grow_file( mapping->file, size_high, size_low )) goto error;
 115     }
 116     else  /* Anonymous mapping (no associated file) */
 117     {
 118         if (!size_high && !size_low)
 119         {
 120             set_error( STATUS_INVALID_PARAMETER );
 121             mapping->file = NULL;
 122             goto error;
 123         }
 124         if (!(mapping->file = create_temp_file( access ))) goto error;
 125         if (!grow_file( mapping->file, size_high, size_low )) goto error;
 126     }
 127     mapping->size_high = size_high;
 128     mapping->size_low  = ROUND_SIZE( 0, size_low );
 129     mapping->protect   = protect;
 130     return &mapping->obj;
 131
 132  error:
 133     release_object( mapping );
 134     return NULL;
 135 }
 136
 137 static void mapping_dump( struct object *obj, int verbose )
 138 {
 139     struct mapping *mapping = (struct mapping *)obj;
 140     assert( obj->ops == &mapping_ops );
 141     fprintf( stderr, "Mapping size=%08x%08x prot=%08x file=%p ",
 142              mapping->size_high, mapping->size_low, mapping->protect, mapping->file );
 143     dump_object_name( &mapping->obj );
 144     fputc( '\n', stderr );
 145 }
 146
 147 static void mapping_destroy( struct object *obj )
 148 {
 149     struct mapping *mapping = (struct mapping *)obj;
 150     assert( obj->ops == &mapping_ops );
 151     if (mapping->file) release_object( mapping->file );
 152 }
 153
 154 int get_page_size(void)
 155 {
 156     if (!page_mask) init_page_size();
 157     return page_mask + 1;
 158 }
 159
 160 /* create a file mapping */
 161 DECL_HANDLER(create_mapping)
 162 {
 163     size_t len = get_req_strlenW( req->name );
 164     struct object *obj;
 165
 166     req->handle = -1;
 167     if ((obj = create_mapping( req->size_high, req->size_low,
 168                                req->protect, req->file_handle, req->name, len )))
 169     {
 170         int access = FILE_MAP_ALL_ACCESS;
 171         if (!(req->protect & VPROT_WRITE)) access &= ~FILE_MAP_WRITE;
 172         req->handle = alloc_handle( current->process, obj, access, req->inherit );
 173         release_object( obj );
 174     }
 175 }
 176
 177 /* open a handle to a mapping */
 178 DECL_HANDLER(open_mapping)
 179 {
 180     size_t len = get_req_strlenW( req->name );
 181     req->handle = open_object( req->name, len, &mapping_ops, req->access, req->inherit );
 182 }
 183
 184 /* get a mapping information */
 185 DECL_HANDLER(get_mapping_info)
 186 {
 187     struct mapping *mapping;
 188
 189     if ((mapping = (struct mapping *)get_handle_obj( current->process, req->handle,
 190                                                      0, &mapping_ops )))
 191     {
 192         req->size_high = mapping->size_high;
 193         req->size_low  = mapping->size_low;
 194         req->protect   = mapping->protect;
 195         if (mapping->file) set_reply_fd( current, file_get_mmap_fd( mapping->file ) );
 196         release_object( mapping );
 197     }
 198 }
 199