NAME
mvalid() — check memory region for validity
SYNOPSIS
#include <sys/types.h>
#include <sys/mman.h>
int mvalid(
caddr_t addr,
size_t len,
int prot
);
Parameters
- addr
The address of the region whose validity is to be checked.
- len
The length in bytes of the region specified by the
addr
parameter.
- prot
The desired access protection for the region.
DESCRIPTION
The
mvalid()
function checks the validity of a memory region.
A region is considered to be valid if accesses of the requested type
are allowed to all addresses in the region.
The
<sys/mman.h>
header file defines
the following access options:
- PROT_READ
The mapped region can be read.
- PROT_WRITE
The mapped region can be written.
- PROT_EXEC
The mapped region can be executed.
The
prot
parameter can be any combination of
PROT_READ,
PROT_WRITE,
and
PROT_EXEC,
ORed together.
RETURN VALUES
The
mvalid()
function returns:
- 0
Success.
Accesses requiring the specified protection
are allowed to all addresses within the specified range of addresses.
- -1
Failure.
errno
is set to indicate the error.
ERRORS
If the
mvalid()
function fails,
errno
may be set to one of the following values:
- EACCES
The range specified by
(addr,
addr+len)
is invalid for the process's address space,
or the range specifies one or more unmapped pages,
or one or more pages of the range
disallows accesses of the specified protection.
- EINVAL
The
prot
parameter is invalid, or the
addr
parameter is not a multiple of the page size as returned by
sysconf(_SC_PAGE_SIZE).
- ENOMEM
The range specified by
(addr,
addr+len)
is invalid for the process's address space,
or the range specifies one or more unmapped pages.
AUTHOR
mvalid()
was developed by HP.
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