minix/lib/libc/sys/mprotect.2
Lionel Sambuc f14fb60209 Libraries updates and cleanup
* Updating common/lib
 * Updating lib/csu
 * Updating lib/libc
 * Updating libexec/ld.elf_so
 * Corrected test on __minix in featuretest to actually follow the
   meaning of the comment.
 * Cleaned up _REENTRANT-related defintions.
 * Disabled -D_REENTRANT for libfetch
 * Removing some unneeded __NBSD_LIBC defines and tests

Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
2013-01-14 11:36:26 +01:00

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.\" $NetBSD: mprotect.2,v 1.24 2011/04/03 06:54:30 jruoho Exp $
.\"
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.\" @(#)mprotect.2 8.1 (Berkeley) 6/9/93
.\"
.Dd April 3, 2011
.Dt MPROTECT 2
.Os
.Sh NAME
.Nm mprotect
.Nd control the protection of pages
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/mman.h
.Ft int
.Fn mprotect "void *addr" "size_t len" "int prot"
.Sh 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.
.Pp
The protections (region accessibility) are specified in the
.Fa prot
argument by
.Tn OR Ns 'ing
the following values:
.Pp
.Bl -tag -width MAP_FIXEDX -offset indent
.It Dv PROT_EXEC
Pages may be executed.
.It Dv PROT_READ
Pages may be read.
.It Dv PROT_WRITE
Pages may be written.
.It Dv PROT_NONE
No permissions.
.El
.Sh RETURN VALUES
Upon successful completion,
a value of 0 is returned.
Otherwise, a value of \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EACCES
A memory protection violation occurred, or the
.Dv PROT_EXEC
flag was attempted on pages which belong to a filesystem mounted with the
.Dv NOEXEC
flag.
.It Bq Er EINVAL
An invalid memory range, or invalid parameters were provided.
.It Bq Er ENOMEM
A resource shortage occurred while internally calling
.Xr uvm_map_protect 9 .
.El
.Sh SEE ALSO
.Xr madvise 2 ,
.Xr mincore 2 ,
.Xr msync 2 ,
.Xr munmap 2
.Sh HISTORY
The
.Fn mprotect
function first appeared in
.Bx 4.4 .