mmap: Document PROT_CAP_*

Consolidate the docuementation in mmap.2 rather than duplicating the
increasingly long description.

lib/libc/sys/mmap.2

@@ -107,7 +107,7 @@ argument by
 .Em or Ns 'ing
 the following values:
 .Pp
-.Bl -tag -width PROT_WRITE -compact
+.Bl -tag -width PROT_CAP_WRITE -compact
 .It Dv PROT_NONE
 Pages may not be accessed.
 .It Dv PROT_READ
@@ -116,8 +116,35 @@ Pages may be read.
 Pages may be written.
 .It Dv PROT_EXEC
 Pages may be executed.
+.It Dv PROT_CAP_READ
+CHERI capabilities may be written to pages.
+.It Dv PROT_CAP_WRITE
+CHERI capabilities may be read from pages.
+.It Dv PROT_CAP_NONE
+CHERI capabilities may not be accessed in pages.
 .El
 .Pp
+When
+.Dv PROT_CAP_NONE
+is combined with
+.Dv PROT_CAP_READ
+or
+.Dv PROT_CAP_WRITE
+it has no effect.
+If no
+.Dv PROT_CAP_*
+flags are included in
+.Fa prot
+than
+.Dv PROT_CAP_READ
+and
+.Dv PROT_CAP_WRITE
+are implied by the presence of
+.Dv PROT_READ
+and
+.Dv PROT_WRITE
+respectively.
+.Pp
 In addition to these protection flags,
 .Fx
 provides the ability to set the maximum protection of a region allocated by

lib/libc/sys/mprotect.2

@@ -47,35 +47,13 @@ system call
 changes the specified pages to have protection
 .Fa prot .
 .Pp
-Currently these protection bits are known,
-which can be combined, OR'd together:
-.Pp
-.Bl -tag -width ".Dv PROT_WRITE" -compact
-.It Dv PROT_NONE
-No permissions at all.
-.It Dv PROT_READ
-The pages can be read.
-.It Dv PROT_WRITE
-The pages can be written.
-.It Dv PROT_EXEC
-The pages can be executed.
-.El
-.Pp
-In addition to these protection flags,
-.Fx
-provides the ability to set the maximum protection of a region
-(which prevents
+The set of protection bits is documented in
+.Xr mmap 2 .
+Like
+.Xr mmap 2 ,
 .Nm
-from upgrading the permissions).
-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.
+can set the maximum protection of a region
+(which prevents upgrading the permissions).
 .Sh RETURN VALUES
 .Rv -std mprotect
 .Sh ERRORS