bionic (2) mprotect.2freebsd.gz

Provided by: freebsd-manpages_11.1-3_all bug

NAME
     mprotect — control the protection of pages


LIBRARY
     Standard C Library (libc, -lc)


SYNOPSIS
     #include <sys/mman.h>

     int
     mprotect(const 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() system call 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() system call first appeared in 4.4BSD.