1  /* Definitions for BSD-style memory management.
       2     Copyright (C) 1994-2023 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     <https://www.gnu.org/licenses/>.  */
      18  
      19  /* These are the bits used by 4.4 BSD and its derivatives.  On systems
      20     (such as GNU) where these facilities are not system services but can be
      21     emulated in the C library, these are the definitions we emulate.  */
      22  
      23  #ifndef _SYS_MMAN_H
      24  # error "Never use <bits/mman.h> directly; include <sys/mman.h> instead."
      25  #endif
      26  
      27  /* Protections are chosen from these bits, OR'd together.  The
      28     implementation does not necessarily support PROT_EXEC or PROT_WRITE
      29     without PROT_READ.  The only guarantees are that no writing will be
      30     allowed without PROT_WRITE and no access will be allowed for PROT_NONE. */
      31  
      32  #define	PROT_NONE	 0x00	/* No access.  */
      33  #define	PROT_READ	 0x04	/* Pages can be read.  */
      34  #define	PROT_WRITE	 0x02	/* Pages can be written.  */
      35  #define	PROT_EXEC	 0x01	/* Pages can be executed.  */
      36  
      37  /* Flags contain mapping type, sharing type and options.  */
      38  
      39  /* Mapping type (must choose one and only one of these).  */
      40  #define MAP_FILE	 0x0001	/* Mapped from a file or device.  */
      41  #define MAP_ANON	 0x0002	/* Allocated from anonymous virtual memory.  */
      42  #define MAP_TYPE	 0x000f	/* Mask for type field.  */
      43  #define MAP_ANONYMOUS	 MAP_ANON /* Linux name. */
      44  
      45  /* Sharing types (must choose one and only one of these).  */
      46  #define MAP_COPY	 0x0020	/* Virtual copy of region at mapping time.  */
      47  #define	MAP_SHARED	 0x0010	/* Share changes.  */
      48  #define	MAP_PRIVATE	 0x0000	/* Changes private; copy pages on write.  */
      49  
      50  /* Other flags.  */
      51  #define	MAP_FIXED	 0x0100	/* Map address must be exactly as requested. */
      52  #define MAP_NOEXTEND	 0x0200	/* For MAP_FILE, don't change file size.  */
      53  #define MAP_HASSEMPHORE 0x0400	/* Region may contain semaphores.  */
      54  #define MAP_INHERIT	 0x0800	/* Region is retained after exec.  */
      55  
      56  /* Advice to `madvise'.  */
      57  #ifdef __USE_MISC
      58  # define MADV_NORMAL	 0	/* No further special treatment.  */
      59  # define MADV_RANDOM	 1	/* Expect random page references.  */
      60  # define MADV_SEQUENTIAL 2	/* Expect sequential page references.  */
      61  # define MADV_WILLNEED	 3	/* Will need these pages.  */
      62  # define MADV_DONTNEED	 4	/* Don't need these pages.  */
      63  #endif
      64  
      65  /* The POSIX people had to invent similar names for the same things.  */
      66  #ifdef __USE_XOPEN2K
      67  # define POSIX_MADV_NORMAL	0 /* No further special treatment.  */
      68  # define POSIX_MADV_RANDOM	1 /* Expect random page references.  */
      69  # define POSIX_MADV_SEQUENTIAL	2 /* Expect sequential page references.  */
      70  # define POSIX_MADV_WILLNEED	3 /* Will need these pages.  */
      71  # define POSIX_MADV_DONTNEED	4 /* Don't need these pages.  */
      72  #endif
      73  
      74  /* Flags to `msync'.  */
      75  #define MS_ASYNC	1		/* Sync memory asynchronously.  */
      76  #define MS_SYNC		0		/* Synchronous memory sync.  */
      77  #define MS_INVALIDATE	2		/* Invalidate the caches.  */
      78  
      79  /* Flags for `mremap'.  */
      80  #ifdef __USE_GNU
      81  # define MREMAP_MAYMOVE	1		/* Mapping address may change.  */
      82  # define MREMAP_FIXED	2		/* Fifth argument sets new address.  */
      83  #endif
      84  
      85  /* Flags for `mlockall' (can be OR'd together).  */
      86  #define MCL_CURRENT	1		/* Lock all currently mapped pages.  */
      87  #define MCL_FUTURE	2		/* Lock all additions to address
      88  					   space.  */