DragonFly On-Line Manual Pages

MPROTECT(2)              DragonFly System Calls Manual             MPROTECT(2)

NAME
     mprotect -- control the protection of pages

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/types.h>
     #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.  A region is the virtual address space defined by the start and
     end addresses of a struct vm_map_entry.

     Currently these protection bits are known, which can be combined, OR'd
     together:

           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
     The mprotect() function returns the value 0 if successful; otherwise the
     value -1 is returned and the global variable errno is set to indicate the
     error.

ERRORS
     The mprotect() function will fail if:

     [EINVAL]           The virtual address range specified by the addr and
                        len arguments is not valid.

     [EACCES]           The calling process was not allowed to change the
                        protection to the value specified by the prot
                        argument.

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

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

DragonFly 4.3                  January 31, 2010                  DragonFly 4.3