source: mainline/uspace/lib/c/generic/mman.c@ 6aae539d

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 6aae539d was fbcdeb8, checked in by Martin Decky <martin@…>, 14 years ago

Remove the two-phase way of creating virtual memory areas (first asking for a mappable address and then mapping it) which was prone to race conditions when two or more calls to as_get_mappable_page() and as_area_create() were interleaved. This for example caused the e1k driver to randomly fail.

The memory area related syscalls and IPC calls have all been altered to accept a special value (void *) -1, representing a demand to atomically search for a mappable address space "hole" and map to it.

Individual changes:

  • IPC_M_SHARE_OUT: the destination address space area is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the callee via a pointer in an IPC reply argument)

  • IPC_M_SHARE_IN: the destination address space ares is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the caller as usual via an IPC argument)

  • SYS_AS_GET_UNMAPPED_AREA was removed
  • dummy implementations of SYS_PHYSMEM_UNMAP and SYS_IOSPACE_DISABLE were added for the sake of symmetry (they do nothing yet)
  • SYS_PHYSMEM_MAP and SYS_DMAMEM_MAP were altered to accept (void *) -1 as address space area base and a lower bound
  • kernel as_area_create() and as_area_share() were altered to accept (void *) -1 as address space area base and a lower bound
  • uspace libraries and programs were altered to reflect the new API
  • Property mode set to 100644
File size: 1.9 KB
RevLine 
[83b1d61]1/*
[df4ed85]2 * Copyright (c) 2006 Ondrej Palkovsky
[83b1d61]3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
[a46da63]29/** @addtogroup libc
[b2951e2]30 * @{
31 */
32/** @file
33 */
34
[2def788]35#include <sys/mman.h>
[5d4e90f0]36#include <sys/types.h>
[83b1d61]37#include <as.h>
38#include <unistd.h>
39
[db24058]40void *mmap(void *start, size_t length, int prot, int flags, int fd,
[ed903174]41 aoff64_t offset)
[83b1d61]42{
43 if (!start)
[fbcdeb8]44 start = (void *) -1;
[83b1d61]45
[db24058]46// if (!((flags & MAP_SHARED) ^ (flags & MAP_PRIVATE)))
[90f5d64]47// return MAP_FAILED;
[db24058]48
49 if (!(flags & MAP_ANONYMOUS))
[90f5d64]50 return MAP_FAILED;
[db24058]51
[83b1d61]52 return as_area_create(start, length, prot);
53}
54
55int munmap(void *start, size_t length)
56{
57 return as_area_destroy(start);
58}
[b2951e2]59
[a46da63]60/** @}
[b2951e2]61 */
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