mprotect (2)

Leading comments

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	The Regents of the University of California.  All rights reserved.

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(The comments found at the beginning of the groff file "man2/mprotect.2freebsd".)

NAME

mprotect - control the protection of pages

LIBRARY

Lb libc

SYNOPSIS

In sys/mman.h Ft int Fn mprotect const void *addr size_t len int prot

DESCRIPTION

The Fn mprotect system call changes the specified pages to have protection Fa 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 Vt 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

Rv -std mprotect

ERRORS

The Fn mprotect system call will fail if:

Bq Er EINVAL

The virtual address range specified by the Fa addr and Fa len arguments is not valid.

Bq Er EACCES

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

SEE ALSO

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

HISTORY

The Fn mprotect system call first appeared in BSD 4.4