Differential D18880 Diff 58844 head/lib/libc/sys/mmap.2

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head/lib/libc/sys/mmap.2

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	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT			.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY			.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF			.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	.\" SUCH DAMAGE.			.\" SUCH DAMAGE.
	.\"			.\"
	.\" @(#)mmap.2 8.4 (Berkeley) 5/11/95			.\" @(#)mmap.2 8.4 (Berkeley) 5/11/95
	.\" $FreeBSD$			.\" $FreeBSD$
	.\"			.\"
	.Dd June 22, 2017			.Dd June 20, 2019
	.Dt MMAP 2			.Dt MMAP 2
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm mmap			.Nm mmap
	.Nd allocate memory, or map files or devices into memory			.Nd allocate memory, or map files or devices into memory
	.Sh LIBRARY			.Sh LIBRARY
	.Lb libc			.Lb libc
	.Sh SYNOPSIS			.Sh SYNOPSIS
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	.It Dv PROT_READ			.It Dv PROT_READ
	Pages may be read.			Pages may be read.
	.It Dv PROT_WRITE			.It Dv PROT_WRITE
	Pages may be written.			Pages may be written.
	.It Dv PROT_EXEC			.It Dv PROT_EXEC
	Pages may be executed.			Pages may be executed.
	.El			.El
	.Pp			.Pp
				In addition to these protection flags,
				.Fx
				provides the ability to set the maximum protection of a region allocated by
				.Nm
				and later altered by
				.Xr mprotect 2 .
				This is accomplished by
				.Em or Ns 'ing
				one or more
				.Dv PROT_
				values wrapped in the
				.Dv PROT_MAX()
				macro into the
				.Fa prot
				argument.
				.Pp
	The			The
	.Fa flags			.Fa flags
	argument specifies the type of the mapped object, mapping options and			argument specifies the type of the mapped object, mapping options and
	whether modifications made to the mapped copy of the page are private			whether modifications made to the mapped copy of the page are private
	to the process or are to be shared with other references.			to the process or are to be shared with other references.
	Sharing, mapping type and options are specified in the			Sharing, mapping type and options are specified in the
	.Fa flags			.Fa flags
	argument by			argument by
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	.Fa offset			.Fa offset
	argument, when			argument, when
	.Fa fd			.Fa fd
	referenced a regular file or shared memory.			referenced a regular file or shared memory.
	.It Bq Er EINVAL			.It Bq Er EINVAL
	An invalid value was passed in the			An invalid value was passed in the
	.Fa prot			.Fa prot
	argument.			argument.
				.It Bq Er EINVAL
				The
				.Fa prot
				argument contains permissions which are not a subset of the specified
				maximum permissions.
	.It Bq Er EINVAL			.It Bq Er EINVAL
	An undefined option was set in the			An undefined option was set in the
	.Fa flags			.Fa flags
	argument.			argument.
	.It Bq Er EINVAL			.It Bq Er EINVAL
	Both			Both
	.Dv MAP_PRIVATE			.Dv MAP_PRIVATE
	and			and
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