nuttx/include/sys/mman.h
ouyangxiangzhen 0451ead2c5 fs/mmap: Ensure anonymous pages are initialized to zero
According to the mmap(2) specification, anonymous pages should be initialized to zero unless the MAP_UNINITIALIZED is specified.

Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
2024-09-13 09:10:21 +08:00

225 lines
8.5 KiB
C

/****************************************************************************
* include/sys/mman.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SYS_MMAN_H
#define __INCLUDE_SYS_MMAN_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Protections are chosen from these bits, OR'd together. NuttX does not
* yet support any of these, but are provided for source level compatibility
*/
#define PROT_NONE 0x0 /* Page may not be accessed */
#define PROT_READ (1 << 0) /* Bit 0: Page may be read */
#define PROT_WRITE (1 << 1) /* Bit 1: Page may be written */
#define PROT_EXEC (1 << 2) /* Bit 2: Page may be executed */
/* mmpa() flags bits. Only MAP_SHARED, MAP_PRIVATE, and MAP_FIXED are
* specified by OpenGroup.org. The rest are unique to NuttX or are
* definitions used by other systems.
*/
/* Sharing types (most are not implemented). */
#define MAP_SHARED (1 << 0) /* Bit 0: Share this mapping */
#define MAP_PRIVATE (1 << 1) /* Bit 1: Create a private copy-on-write mapping */
#define MAP_TYPE (3 << 0) /* Mask for type of mapping */
#define MAP_FIXED (1 << 2) /* Bit 2: Map to specified address exactly */
#define MAP_FILE (1 << 3) /* Bit 3: The mapping is backed by a file */
#define MAP_ANONYMOUS (1 << 4) /* Bit 4: The mapping is not backed by any file */
#define MAP_ANON MAP_ANONYMOUS /* Alias */
/* These are Linux-specific (most are not implemented). */
#define MAP_GROWSDOWN (1 << 5) /* Bit 5: Used to stack allocations */
#define MAP_DENYWRITE (1 << 6) /* Bit 6: Do not permit writes to file */
#define MAP_EXECUTABLE (1 << 7) /* Bit 7: Mark it as an executable */
#define MAP_LOCKED (1 << 8) /* Bit 8: Lock pages mapped into memory */
#define MAP_NORESERVE (1 << 9) /* Bit 9: Do not reserve swap space for this mapping */
#define MAP_POPULATE (1 << 10) /* Bit 10: populate (prefault) page tables */
#define MAP_NONBLOCK (1 << 11) /* Bit 11: Do not block on IO */
#define MAP_UNINITIALIZED (1 << 26) /* Bit 26: Do not clear the anonymous pages */
/* Failure return */
#define MAP_FAILED ((FAR void*)-1)
/* The following flags are used with msync() */
#define MS_ASYNC 0x01 /* Perform asynchronous writes */
#define MS_SYNC 0x02 /* Perform synchronous writes */
#define MS_INVALIDATE 0x04 /* Invalidate mapping */
/* The following flags are used with mlockall() */
#define MCL_CURRENT 0x01 /* Lock currently mapped pages */
#define MCL_FUTURE 0x02 /* Lock pages that become mapped */
/* If the Advisory Information and either the Memory Mapped Files or Shared
* Memory Objects options are supported, values for advice used by
* posix_madvise() are defined as follows:
*
* POSIX_MADV_NORMAL
* The application has no advice to give on its behavior with respect to
* the specified range. It is the default characteristic if no advice is
* given for a range of memory.
* POSIX_MADV_SEQUENTIAL
* The application expects to access the specified range sequentially from
* lower addresses to higher addresses.
* POSIX_MADV_RANDOM
* The application expects to access the specified range in a random order.
* POSIX_MADV_WILLNEED
* The application expects to access the specified range in the near
* future.
* POSIX_MADV_DONTNEED
* The application expects that it will not access the specified range in
* the near future.
*/
#define POSIX_MADV_NORMAL (0)
#define POSIX_MADV_SEQUENTIAL (1)
#define POSIX_MADV_RANDOM (2)
#define POSIX_MADV_WILLNEED (3)
#define POSIX_MADV_DONTNEED (4)
#define MADV_NORMAL POSIX_MADV_NORMAL
#define MADV_SEQUENTIAL POSIX_MADV_SEQUENTIAL
#define MADV_RANDOM POSIX_MADV_RANDOM
#define MADV_WILLNEED POSIX_MADV_WILLNEED
#define MADV_DONTNEED POSIX_MADV_DONTNEED
/* The following flags are defined since Linux 2.6.38.
* None of these flags have been implemented yet.
* MADV_HUGEPAGE
* Enable Transparent Huge Pages (THP) for pages.
* MADV_NOHUGEPAGE
* Ensure the pages will not be backed by transparent hugepages.
*/
#define MADV_HUGEPAGE (14)
#define MADV_NOHUGEPAGE (15)
/* The following flags are defined for posix_typed_mem_open():
*
* POSIX_TYPED_MEM_ALLOCATE
* Allocate on mmap().
* POSIX_TYPED_MEM_ALLOCATE_CONTIG
* Allocate contiguously on mmap().
* POSIX_TYPED_MEM_MAP_ALLOCATABLE
* Map on mmap(), without affecting allocatability.
*/
#define POSIX_TYPED_MEM_ALLOCATE (0)
#define POSIX_TYPED_MEM_ALLOCATE_CONTIG (1)
#define POSIX_TYPED_MEM_MAP_ALLOCATABLE (2)
/* Flags for memfd_create(). */
#define MFD_CLOEXEC O_CLOEXEC
#define MFD_ALLOW_SEALING (1 << 16)
#define MFD_HUGETLB (1 << 17)
#define MFD_HUGE_SHIFT 26
#define MFD_HUGE_MASK 0x3f
#define MFD_HUGE_64KB (16 << MFD_HUGE_SHIFT)
#define MFD_HUGE_512KB (19 << MFD_HUGE_SHIFT)
#define MFD_HUGE_1MB (20 << MFD_HUGE_SHIFT)
#define MFD_HUGE_2MB (21 << MFD_HUGE_SHIFT)
#define MFD_HUGE_8MB (23 << MFD_HUGE_SHIFT)
#define MFD_HUGE_16MB (24 << MFD_HUGE_SHIFT)
#define MFD_HUGE_32MB (25 << MFD_HUGE_SHIFT)
#define MFD_HUGE_256MB (28 << MFD_HUGE_SHIFT)
#define MFD_HUGE_512MB (29 << MFD_HUGE_SHIFT)
#define MFD_HUGE_1GB (30 << MFD_HUGE_SHIFT)
#define MFD_HUGE_2GB (31 << MFD_HUGE_SHIFT)
#define MFD_HUGE_16GB (34 << MFD_HUGE_SHIFT)
#if defined(CONFIG_FS_LARGEFILE)
# define mmap64 mmap
#endif
#define madvise posix_madvise
/****************************************************************************
* Public Type Definitions
****************************************************************************/
struct posix_typed_mem_info
{
size_t posix_tmi_length; /* Maximum length which may be allocated from a
* typed memory object */
};
/****************************************************************************
* Public Data
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
int mlock(FAR const void *addr, size_t len);
int mlockall(int flags);
FAR void *mmap(FAR void *start, size_t length, int prot, int flags, int fd,
off_t offset);
int mprotect(FAR void *addr, size_t len, int prot);
int msync(FAR void *addr, size_t len, int flags);
int munlock(FAR const void *addr, size_t len);
int munlockall(void);
int munmap(FAR void *start, size_t length);
int posix_madvise(FAR void *addr, size_t len, int advice);
int posix_mem_offset(FAR const void *addr, size_t len, FAR off_t *off,
FAR size_t *contig_len, FAR int *fildes);
int posix_typed_mem_get_info(int fildes,
FAR struct posix_typed_mem_info *info);
int posix_typed_mem_open(FAR const char *name, int oflag, int tflag);
int shm_open(FAR const char *name, int oflag, mode_t mode);
int shm_unlink(FAR const char *name);
int memfd_create(FAR const char *name, unsigned int flags);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_MMAN_H */