Index: share/man/man7/mitigations.7
===================================================================
--- share/man/man7/mitigations.7
+++ share/man/man7/mitigations.7
@@ -234,8 +234,20 @@
 .\"
 .\".Ss Stack Smashing Protection (SSP)
 .\"
-.\".Ss Supervisor mode memory protection
-.\"
+.Ss Supervisor mode memory protection
+Certain processors include features that prevent unintended access to memory
+pages not owned by the kernel.
+This is intended to prevent exploitation of kernel bugs from userland.
+.Bl -column -offset indent "Architecture" "Feature" "Access Type Prevented"
+.It Sy Architecture Ta Sy Feature Ta Sy Access Type Prevented
+.It amd64       Ta SMAP  Ta Read / Write / Execute
+.It amd64       Ta SMEP  Ta Execute
+.It arm64       Ta PAN   Ta Read / Write / Execute
+.It arm64       Ta PXN   Ta Execute
+.El
+.Pp
+These features are used by the kernel.
+There is no user-facing configuration.
 .Ss Hardware vulnerability controls
 See
 .Xr security 7