Module Name: src
Committed By: riastradh
Date: Tue Apr 21 04:05:57 UTC 2015
Modified Files:
src/sys/rump/librump/rumpkern: hyperentropy.c
Log Message:
Revert previous -- a little too quick on the commit trigger.
Ran some tests but not enough. There is a deadlock against myself:
rndsink_request acquires rndsinks_lock
-> rnd_getmore
-> hyperentropy feedrandom (or any other rndsource callback)
-> rnd_add_data
-> rndsinks_distribute acquires rndsinks_lock
Need to break this cycle before rndsource callbacks can invoke
rnd_add_data.
To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/rump/librump/rumpkern/hyperentropy.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/librump/rumpkern/hyperentropy.c
diff -u src/sys/rump/librump/rumpkern/hyperentropy.c:1.9 src/sys/rump/librump/rumpkern/hyperentropy.c:1.10
--- src/sys/rump/librump/rumpkern/hyperentropy.c:1.9 Tue Apr 21 03:53:50 2015
+++ src/sys/rump/librump/rumpkern/hyperentropy.c Tue Apr 21 04:05:57 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: hyperentropy.c,v 1.9 2015/04/21 03:53:50 riastradh Exp $ */
+/* $NetBSD: hyperentropy.c,v 1.10 2015/04/21 04:05:57 riastradh Exp $ */
/*
* Copyright (c) 2014 Antti Kantee. All Rights Reserved.
@@ -26,9 +26,10 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hyperentropy.c,v 1.9 2015/04/21 03:53:50 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hyperentropy.c,v 1.10 2015/04/21 04:05:57 riastradh Exp $");
#include <sys/param.h>
+#include <sys/atomic.h>
#include <sys/kmem.h>
#include <sys/rndpool.h>
#include <sys/rndsource.h>
@@ -38,10 +39,12 @@ __KERNEL_RCSID(0, "$NetBSD: hyperentropy
#include "rump_private.h"
static krndsource_t rndsrc;
+static volatile unsigned hyperentropy_wanted;
+static void *feedrandom_softint;
#define MAXGET (RND_POOLBITS/NBBY)
static void
-feedrandom_cb(size_t bytes, void *cookie __unused)
+feedrandom(size_t bytes)
{
uint8_t *rnddata;
size_t dsize;
@@ -53,11 +56,42 @@ feedrandom_cb(size_t bytes, void *cookie
kmem_intr_free(rnddata, MAXGET);
}
+static void
+feedrandom_intr(void *cookie __unused)
+{
+
+ feedrandom(atomic_swap_uint(&hyperentropy_wanted, 0));
+}
+
+static void
+feedrandom_cb(size_t bytes, void *cookie __unused)
+{
+ unsigned old, new;
+
+ do {
+ old = hyperentropy_wanted;
+ new = ((MAXGET - old) < bytes? MAXGET : (old + bytes));
+ } while (atomic_cas_uint(&hyperentropy_wanted, old, new) != old);
+
+ softint_schedule(feedrandom_softint);
+}
+
void
rump_hyperentropy_init(void)
{
- rndsource_setcb(&rndsrc, &feedrandom_cb, &rndsrc);
- rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
- RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
+ if (rump_threads) {
+ feedrandom_softint =
+ softint_establish(SOFTINT_CLOCK|SOFTINT_MPSAFE,
+ feedrandom_intr, NULL);
+ KASSERT(feedrandom_softint != NULL);
+ rndsource_setcb(&rndsrc, feedrandom_cb, &rndsrc);
+ rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
+ RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
+ } else {
+ /* without threads, just fill the pool */
+ rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
+ RND_FLAG_COLLECT_VALUE);
+ feedrandom(MAXGET);
+ }
}
