osx man page for mprotect

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

NAME
     mprotect -- control the protection of pages

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 but Mac OS X's current implementation does.

     When a program violates the protections of a page, it gets a SIGBUS or SIGSEGV signal.

     Currently prot can be one or more of the following:

     PROT_NONE	 No permissions at all.
     PROT_READ	 The pages can be read.
     PROT_WRITE  The pages can be written.
     PROT_EXEC	 The pages can be executed.

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
     mprotect() will fail if:

     [EACCES]		The requested protection conflicts with the access permissions of the process on the specified address range.

     [EINVAL]		addr is not a multiple of the page size (i.e.  addr is not page-aligned).

     [ENOTSUP]		The combination of accesses requested in prot is not supported.

LEGACY SYNOPSIS
     #include <sys/types.h>
     #include <sys/mman.h>

     The include file <sys/types.h> is necessary.

     int
     mprotect(caddr_t addr, size_t len, int prot);

     The type of addr has changed.

SEE ALSO
     madvise(2), mincore(2), msync(2), munmap(2), compat(5)

HISTORY
     The mprotect() function first appeared in 4.4BSD.

BSD
								 October 16, 2008							       BSD