mvalid(2)mvalid(2)NAMEmvalid - 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
Specifies the address of the region whose validity is to be checked.
Specifies length in bytes of the region specified by the addr parame‐
ter. Specifies 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: The
mapped region can be read. The mapped region can be written. 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 (zero) if accesses requiring the speci‐
fied protection are allowed to all addresses within the specified range
of addresses. Otherwise, the mvalid() function returns -1 and sets
errno to indicate the error.
ERRORS
If the mvalid() function fails, errno may be set to one of the follow‐
ing values: The range specified by [addr, addr + len) is invalid for
the process' 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. The prot parameter is invalid, or the addr
parameter is not a multiple of the page size as returned by
sysconf(_SC_PAGE_SIZE).
SEE ALSO
Functions: mmap(2), mprotect(2), sysconf(3)mvalid(2)
