mprotect(2)							System Calls Manual						       mprotect(2)

NAME

       mprotect() - set or check protection of memory mapping

SYNOPSIS

DESCRIPTION

       The  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 to be that specified by prot.  Legitimate values for prot are the same  as  those  permitted  for  and  are
       defined in

	      Page can be read.

	      Page can be written.

	      Page can be executed.

	      Page cannot be accessed.

	      Check page effective permissions

       If  flag  is specified, checks the access protections on the mappings specified with the rest of prot value to see if the requested permis-
       sions are set.

       If the address range being modified corresponds to a mapped file that was mapped with grants write  access  permission  only  if  the  file
       descriptor  used to map the file was opened for writing.  If the address range corresponds to a mapped file that was mapped with the or the
       flag, grants all requested access permissions.

       When fails for reasons other than the protections on some of the pages in the range [addr, addr+len] may have been changed.

       For example, if an error occurs on some page at an addr2, then may  have  modified  the	protections  of  all  whole  pages  in	the  range
       [addr,addr2].

RETURN VALUE

       Upon successful completion, returns Otherwise, it returns and sets to indicate the error.

ERRORS

       The function will fail if:

	      The	     prot  argument  specifies	a  protection that violates, or is different than (in the case where flag is present), the
			     access permission the process has to the underlying memory object.

	      prot	     is invalid, or addr is not a multiple of the page size as returned by

	      The range specified by
			     [addr, addr+len] (from, and including, addr to, but not including, addr+len) is invalid for the address  space  of  a
			     process, or the range specifies one or more unmapped pages.

	      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	     prot argument specifies over a mapping and there are insufficient memory resources to reserve for locking the private
			     page.

AUTHOR

       was developed by HP, AT&T, and OSF.

SEE ALSO

       mmap(2), sysconf(2), <sys/mman.h>.

STANDARDS CONFORMANCE

																       mprotect(2)