Fill out the mincore(2) manual page a little; define the NetBSD call

to be like the Solaris call.

lib/libc/sys/mincore.2

@@ -1,4 +1,4 @@
-.\"	$NetBSD: mincore.2,v 1.9 1998/02/03 21:12:50 perry Exp $
+.\"	$NetBSD: mincore.2,v 1.10 1999/06/07 01:42:30 thorpej Exp $
 .\"
 .\" Copyright (c) 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -33,7 +33,7 @@
 .\"
 .\"	@(#)mincore.2	8.1 (Berkeley) 6/9/93
 .\"
-.Dd June 9, 1993
+.Dd June 6, 1999
 .Dt MINCORE 2
 .Os
 .Sh NAME
@@ -49,17 +49,50 @@ The
 .Fn mincore
 system call
 allows a process to obtain information about whether pages are
-core resident.
-Here the current core residency of the pages is returned
-in the character array 
-.Fa vec ,
-with a value of 1 meaning that the page is in-core.
+core resident.  The status of the memory range is returned in the
+character-per-page array
+.Ar vec .
+If the page is resident, the least significant bit of the corresponding
+character in
+.Ar vec
+will be set.  Other bits are reserved for additional information
+which future implementations may return.
+.Pp
+Note that the status of each page may change between the call to
+.Fn mincore
+and the return of the page status information.  In order to guarantee
+that pages will remain in core, the address range must be locked with
+.Xr mlock 2 .
+.Sh RETURN VALUES
+.Fn mincore
+returns 0 on success, or -1 on failure and sets the variable
+.Va errno
+to indicate the error.
+.Sh ERRORS
+The    
+.Fn mincore
+call will fail if:
+.Bl -tag -width Er
+.It Bq Er EFAULT
+.Ar vec
+points to an illegal address.
+.It Bq Er EINVAL
+.Ar addr
+is not a multiple of the system page size.
+.It Bq Er EINVAL
+.Ar len
+is equal to 0.
+.It Bq Er ENOMEM
+The address range specified is invalid for the calling process,
+or one or more of the pages specified in the range are not mapped.
+.El
 .Sh SEE ALSO
 .Xr madvise 2 ,
 .Xr mlock 2 ,
 .Xr mprotect 2 ,
 .Xr msync 2 ,
-.Xr munmap 2
+.Xr munmap 2 ,
+.Xr sysconf 3
 .Sh HISTORY
 The
 .Fn mincore