Put on my peril sensitive sunglasses and add a flags field to the internal

sysctl routines and state.  Add some code to use it for signalling the need
to downconvert a data structure to 32 bits on a 64 bit OS when requested by
a 32 bit app.

I tried to do this in a generic abi wrapper that intercepted the sysctl
oid's, or looked up the format string etc, but it was a real can of worms
that turned into a fragile mess before I even got it partially working.

With this, we can now run 'sysctl -a' on a 32 bit sysctl binary and have
it not abort.  Things like netstat, ps, etc have a long way to go.

This also fixes a bug in the kern.ps_strings and kern.usrstack hacks.
These do matter very much because they are used by libc_r and other things.

1 files changed, 18 insertions, 2 deletions

diff --git a/sys/vm/vm_meter.c b/sys/vm/vm_meter.c
index 4c09acd..4c3d60b 100644
--- a/sys/vm/vm_meter.c
+++ b/sys/vm/vm_meter.c
@@ -85,8 +85,24 @@ SYSCTL_UINT(_vm, VM_V_PAGEOUT_FREE_MIN, v_pageout_free_min,
 SYSCTL_UINT(_vm, OID_AUTO, v_free_severe,
 	CTLFLAG_RW, &cnt.v_free_severe, 0, "");
 
-SYSCTL_STRUCT(_vm, VM_LOADAVG, loadavg, CTLFLAG_RD, 
-    &averunnable, loadavg, "Machine loadaverage history");
+static int
+sysctl_vm_loadavg(SYSCTL_HANDLER_ARGS)
+{
+#ifdef SCTL_MASK32
+	u_int32_t la[4];
+
+	if (req->flags & SCTL_MASK32) {
+		la[0] = averunnable.ldavg[0];
+		la[1] = averunnable.ldavg[1];
+		la[2] = averunnable.ldavg[2];
+		la[3] = averunnable.fscale;
+		return SYSCTL_OUT(req, la, sizeof(la));
+	} else
+#endif
+		return SYSCTL_OUT(req, &averunnable, sizeof(averunnable));
+}
+SYSCTL_PROC(_vm, VM_LOADAVG, loadavg, CTLTYPE_STRUCT|CTLFLAG_RD, 
+    NULL, 0, sysctl_vm_loadavg, "S,loadavg", "Machine loadaverage history");
 
 static int
 vmtotal(SYSCTL_HANDLER_ARGS)