Proposed fix; stage 1 (Was: svn commit: r239569 - head/etc/rc.d)

[David O'Brien]

On Thu, Sep 20, 2012 at 08:44:10AM -0400, John Baldwin wrote:
> I leave it up to someone else to explicitly ok that this data goes into
> the RANDOM_INTERRUPT queue with the claim of 2 bits of entropy:
> 
> Index: sys/kern/kern_intr.c
...
>+	if (harvest.swi) {
>+		CTR3(KTR_INTR, "swi_sched: pid %d (%s) gathering entropy",
>+		    curproc->p_pid, curthread->td_name);

		CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
		    curproc->p_pid, curthread->td_name);
--or-- 
		CTR2(KTR_INTR, "swi_sched: pid %d (%s) gathering entropy",
		    curproc->p_pid, curthread->td_name);

This seems to have captured some harvesting.
I applied your patch and only enabled harvest.swi with:
Index: harvest.c
===================================================================
--- harvest.c	(revision 240694)
+++ harvest.c	(working copy)
@@ -51 +51,7 @@ static int read_random_phony(void *, int
-struct harvest_select harvest = { 1, 1, 1, 0 };
+struct harvest_select harvest = {
+	0,	/*ethernet*/
+	0,	/*pt2pt*/
+	0,	/*intr*/
+	1,	/*swi*/
+	0,	/*devprobe*/
+};


ngoc# sysctl kern.random
kern.random.yarrow.gengateinterval: 10
kern.random.yarrow.bins: 10
kern.random.yarrow.fastthresh: 192
kern.random.yarrow.slowthresh: 256
kern.random.yarrow.slowoverthresh: 2
kern.random.sys.seeded: 1
kern.random.sys.harvest.ethernet: 0
kern.random.sys.harvest.point_to_point: 0
kern.random.sys.harvest.devprobe: 0
kern.random.sys.harvest.interrupt: 0
kern.random.sys.harvest.swi: 1
kern.random.sys.harvest.entropy_processed: write=0/0, keyboard=0/0,
mouse=0/0, net=0/0, interrupt=4235/3, device=0/0 pure=0/0

(note, this system is initialized as non-seeded as shown in my previous patch)
-- 
-- David  (obrien at FreeBSD.org)