mvalid(2) [osf1 man page]

mvalid(2)							System Calls Manual							 mvalid(2)

NAME

       mvalid - Checks 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 specified 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 following 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).

RELATED INFORMATION

       Functions: mmap(2), mprotect(2), sysconf(3) delim off

																	 mvalid(2)

mprotect(2)							   System Calls 						       mprotect(2)

NAME

       mprotect - set protection of memory mapping

SYNOPSIS

       #include <sys/mman.h>

       int mprotect(void *addr, size_t len, int prot);

DESCRIPTION

       The   mprotect()  function changes the access protections on the mappings specified by the range [addr, addr + len), rounding len up to the
       next multiple of the page size as returned by sysconf(3C), to be that specified by prot. Legitimate values for prot are the same  as  those
       permitted for mmap(2) and are defined in <sys/mman.h> as:

       PROT_READ       /* page can be read */

       PROT_WRITE      /* page can be written */

       PROT_EXEC       /* page can be executed */

       PROT_NONE       /* page can not be accessed */

       When  mprotect()  fails	for  reasons other than EINVAL, the protections on some of the pages in the range [addr, addr + len) may have been
       changed. If the error occurs on some page at addr2, then the protections of all whole pages in the range [addr, addr2] will have been modi-
       fied.

RETURN VALUES

       Upon successful completion, mprotect() returns 0. Otherwise, it returns -1 and sets errno to indicate the error.

ERRORS

       The mprotect() function will fail if:

       EACCES	       The  prot  argument  specifies  a  protection  that violates the access permission the process has to the underlying memory
		       object.

       EINVAL	       The len argument has a value equal to 0, or addr is not a multiple of the page size as returned by sysconf(3C).

       ENOMEM	       Addresses in the range [addr, addr + len) are invalid for the address space of a process, or  specify  one  or  more  pages
		       which are not mapped.

       The mprotect() function may fail if:

       EAGAIN	       The  address  range  [addr,  addr  +  len)  includes one or more pages that have been locked in memory and that were mapped
		       MAP_PRIVATE; prot includes PROT_WRITE; and the system has insufficient resources to reserve memory for  the  private  pages
		       that may be created. These private pages may be created by store operations in the now-writable address range.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       mmap(2), plock(3C), mlock(3C), mlockall(3C), sysconf(3C), attributes(5), standards(5)

SunOS 5.10							    12 Jan 1998 						       mprotect(2)