MPROTECT(2)						      BSD System Calls Manual						       MPROTECT(2)

NAME

     mprotect -- control the protection of pages

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/mman.h>

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

DESCRIPTION

     The mprotect() system call changes the specified pages to have protection prot.  Not all implementations will guarantee protection on a page
     basis; the granularity of protection changes may be as large as an entire region.

     The protections (region accessibility) are specified in the prot argument by OR'ing the following values:

	   PROT_EXEC   Pages may be executed.

	   PROT_READ   Pages may be read.

	   PROT_WRITE  Pages may be written.

	   PROT_NONE   No permissions.

RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS

     [EACCES]		A memory protection violation occurred, or the PROT_EXEC flag was attempted on pages which belong to a filesystem mounted
			with the NOEXEC flag.

     [EINVAL]		An invalid memory range, or invalid parameters were provided.

     [ENOMEM]		A resource shortage occurred while internally calling uvm_map_protect(9).

SEE ALSO

     madvise(2), mincore(2), msync(2), munmap(2)

HISTORY

     The mprotect() function first appeared in 4.4BSD.

BSD
								   April 3, 2011							       BSD