kernel: switch to fast portable chacha based seed-once random number generator

3 files changed, 6 insertions, 153 deletions

diff --git a/sys/src/9/pc/devarch.c b/sys/src/9/pc/devarch.c
index f3be061cb..0b4cad252 100644
--- a/sys/src/9/pc/devarch.c
+++ b/sys/src/9/pc/devarch.c
@@ -872,6 +872,11 @@ cpuidentify(void)
 		fprestore = fpx87restore;
 	}
 
+	if(strcmp(m->cpuidid, "GenuineIntel") == 0 && (m->cpuidcx & Rdrnd) != 0)
+		hwrandbuf = rdrandbuf;
+	else
+		hwrandbuf = nil;
+
 	cputype = t;
 	return t->family;
 }
diff --git a/sys/src/9/pc/mkfile b/sys/src/9/pc/mkfile
index 96ab2c623..c6e683e22 100644
--- a/sys/src/9/pc/mkfile
+++ b/sys/src/9/pc/mkfile
@@ -32,6 +32,7 @@ PORT=\
 	proc.$O\
 	qio.$O\
 	qlock.$O\
+	random.$O\
 	rdb.$O\
 	rebootcmd.$O\
 	segment.$O\
@@ -52,7 +53,6 @@ OBJ=\
 	memory.$O\
 	mmu.$O\
 	trap.$O\
-	pcrandom.$O\
 	$CONF.root.$O\
 	$CONF.rootc.$O\
 	$DEVS\
diff --git a/sys/src/9/pc/pcrandom.c b/sys/src/9/pc/pcrandom.c
deleted file mode 100644
index 386d7bf8e..000000000
--- a/sys/src/9/pc/pcrandom.c
+++ /dev/null
@@ -1,152 +0,0 @@
-#include	"u.h"
-#include	"../port/lib.h"
-#include	"mem.h"
-#include	"dat.h"
-#include	"fns.h"
-#include	"../port/error.h"
-
-static int haverdrand;
-
-struct Rb
-{
-	QLock;
-	Rendez	producer;
-	Rendez	consumer;
-	ulong	randomcount;
-	uchar	buf[128];
-	uchar	*ep;
-	uchar	*rp;
-	uchar	*wp;
-	uchar	next;
-	uchar	wakeme;
-	ushort	bits;
-	ulong	randn;
-} rb;
-
-static int
-rbnotfull(void*)
-{
-	int i;
-
-	i = rb.rp - rb.wp;
-	return i != 1 && i != (1 - sizeof(rb.buf));
-}
-
-static int
-rbnotempty(void*)
-{
-	return rb.wp != rb.rp;
-}
-
-static void
-genrandom(void*)
-{
-	up->basepri = PriNormal;
-	up->priority = up->basepri;
-
-	while(waserror())
-		;
-	for(;;){
-		if(++rb.randomcount <= 100000)
-			continue;
-		if(anyhigher())
-			sched();
-		if(!rbnotfull(0))
-			sleep(&rb.producer, rbnotfull, 0);
-	}
-}
-
-/*
- *  produce random bits in a circular buffer
- */
-static void
-randomclock(void)
-{
-	if(rb.randomcount == 0 || !rbnotfull(0))
-		return;
-
-	rb.bits = (rb.bits<<2) ^ rb.randomcount;
-	rb.randomcount = 0;
-
-	rb.next++;
-	if(rb.next != 8/2)
-		return;
-	rb.next = 0;
-
-	*rb.wp ^= rb.bits;
-	if(rb.wp+1 == rb.ep)
-		rb.wp = rb.buf;
-	else
-		rb.wp = rb.wp+1;
-
-	if(rb.wakeme)
-		wakeup(&rb.consumer);
-}
-
-void
-randominit(void)
-{
-	if(!strcmp(m->cpuidid, "GenuineIntel")
-		 && (m->cpuidcx & Rdrnd)){
-		haverdrand = 1;
-	}
-	else{
-		/* Frequency close but not equal to HZ */
-		addclock0link(randomclock, MS2HZ+3);
-		rb.ep = rb.buf + sizeof(rb.buf);
-		rb.rp = rb.wp = rb.buf;
-		kproc("genrandom", genrandom, 0);
-	}
-}
-
-/*
- *  consume random bytes from a circular buffer
- */
-ulong
-randomread(void *xp, ulong n)
-{
-	uchar *e, *p;
-	ulong x;
-
-	p = xp;
-
-	if(haverdrand){
-		rdrandbuf(p, n);
-		return n;
-	}
-
-	if(waserror()){
-		qunlock(&rb);
-		nexterror();
-	}
-
-	qlock(&rb);
-	for(e = p + n; p < e; ){
-		if(rb.wp == rb.rp){
-			rb.wakeme = 1;
-			wakeup(&rb.producer);
-			sleep(&rb.consumer, rbnotempty, 0);
-			rb.wakeme = 0;
-			continue;
-		}
-
-		/*
-		 *  beating clocks will be predictable if
-		 *  they are synchronized.  Use a cheap pseudo-
-		 *  random number generator to obscure any cycles.
-		 */
-		x = rb.randn*1103515245 ^ *rb.rp;
-		*p++ = rb.randn = x;
-
-		if(rb.rp+1 == rb.ep)
-			rb.rp = rb.buf;
-		else
-			rb.rp = rb.rp+1;
-	}
-	qunlock(&rb);
-	poperror();
-
-	wakeup(&rb.producer);
-
-	return n;
-}