bits/mman-linux.h

   1 /* Definitions for POSIX memory map interface.  Linux generic version.
   2    Copyright (C) 2001-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_MMAN_H
  20 # error "Never use <bits/mman-linux.h> directly; include <sys/mman.h> instead."
  21 #endif
  22
  23 /* The following definitions basically come from the kernel headers.
  24    But the kernel header is not namespace clean.
  25
  26    This file is also used by some non-Linux configurations of the
  27    GNU C Library, for other systems that use these same bit values.  */
  28
  29
  30 /* Protections are chosen from these bits, OR'd together.  The
  31    implementation does not necessarily support PROT_EXEC or PROT_WRITE
  32    without PROT_READ.  The only guarantees are that no writing will be
  33    allowed without PROT_WRITE and no access will be allowed for PROT_NONE. */
  34
  35 #define PROT_READ       0x1             /* Page can be read.  */
  36 #define PROT_WRITE      0x2             /* Page can be written.  */
  37 #define PROT_EXEC       0x4             /* Page can be executed.  */
  38 #define PROT_NONE       0x0             /* Page can not be accessed.  */
  39 #define PROT_GROWSDOWN  0x01000000      /* Extend change to start of
  40                                            growsdown vma (mprotect only).  */
  41 #define PROT_GROWSUP    0x02000000      /* Extend change to start of
  42                                            growsup vma (mprotect only).  */
  43
  44 /* Sharing types (must choose one and only one of these).  */
  45 #define MAP_SHARED      0x01            /* Share changes.  */
  46 #define MAP_PRIVATE     0x02            /* Changes are private.  */
  47 #ifdef __USE_MISC
  48 # define MAP_TYPE       0x0f            /* Mask for type of mapping.  */
  49 #endif
  50
  51 /* Other flags.  */
  52 #define MAP_FIXED       0x10            /* Interpret addr exactly.  */
  53 #ifdef __USE_MISC
  54 # define MAP_FILE       0
  55 # ifdef __MAP_ANONYMOUS
  56 #  define MAP_ANONYMOUS __MAP_ANONYMOUS /* Don't use a file.  */
  57 # else
  58 #  define MAP_ANONYMOUS 0x20            /* Don't use a file.  */
  59 # endif
  60 # define MAP_ANON       MAP_ANONYMOUS
  61 /* When MAP_HUGETLB is set bits [26:31] encode the log2 of the huge page size.  */
  62 # define MAP_HUGE_SHIFT 26
  63 # define MAP_HUGE_MASK  0x3f
  64 #endif
  65
  66 /* Flags to `msync'.  */
  67 #define MS_ASYNC        1               /* Sync memory asynchronously.  */
  68 #define MS_SYNC         4               /* Synchronous memory sync.  */
  69 #define MS_INVALIDATE   2               /* Invalidate the caches.  */
  70
  71 /* Flags for `mremap'.  */
  72 #ifdef __USE_GNU
  73 # define MREMAP_MAYMOVE 1
  74 # define MREMAP_FIXED   2
  75 #endif
  76
  77 /* Advice to `madvise'.  */
  78 #ifdef __USE_MISC
  79 # define MADV_NORMAL      0     /* No further special treatment.  */
  80 # define MADV_RANDOM      1     /* Expect random page references.  */
  81 # define MADV_SEQUENTIAL  2     /* Expect sequential page references.  */
  82 # define MADV_WILLNEED    3     /* Will need these pages.  */
  83 # define MADV_DONTNEED    4     /* Don't need these pages.  */
  84 # define MADV_FREE        8     /* Free pages only if memory pressure.  */
  85 # define MADV_REMOVE      9     /* Remove these pages and resources.  */
  86 # define MADV_DONTFORK    10    /* Do not inherit across fork.  */
  87 # define MADV_DOFORK      11    /* Do inherit across fork.  */
  88 # define MADV_MERGEABLE   12    /* KSM may merge identical pages.  */
  89 # define MADV_UNMERGEABLE 13    /* KSM may not merge identical pages.  */
  90 # define MADV_HUGEPAGE    14    /* Worth backing with hugepages.  */
  91 # define MADV_NOHUGEPAGE  15    /* Not worth backing with hugepages.  */
  92 # define MADV_DONTDUMP    16    /* Explicity exclude from the core dump,
  93                                    overrides the coredump filter bits.  */
  94 # define MADV_DODUMP      17    /* Clear the MADV_DONTDUMP flag.  */
  95 # define MADV_HWPOISON    100   /* Poison a page for testing.  */
  96 #endif
  97
  98 /* The POSIX people had to invent similar names for the same things.  */
  99 #ifdef __USE_XOPEN2K
 100 # define POSIX_MADV_NORMAL      0 /* No further special treatment.  */
 101 # define POSIX_MADV_RANDOM      1 /* Expect random page references.  */
 102 # define POSIX_MADV_SEQUENTIAL  2 /* Expect sequential page references.  */
 103 # define POSIX_MADV_WILLNEED    3 /* Will need these pages.  */
 104 # define POSIX_MADV_DONTNEED    4 /* Don't need these pages.  */
 105 #endif
 106
 107 /* Flags for `mlockall'.  */
 108 #ifndef MCL_CURRENT
 109 # define MCL_CURRENT    1               /* Lock all currently mapped pages.  */
 110 # define MCL_FUTURE     2               /* Lock all additions to address
 111                                            space.  */
 112 # define MCL_ONFAULT    4               /* Lock all pages that are
 113                                            faulted in.  */
 114 #endif