MPROTECT(2)               NetBSD 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_EXECUTE 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().

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

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

NetBSD 5.0_STABLE               October 7, 2006              NetBSD 5.0_STABLE
