Module Name: src
Committed By: riastradh
Date: Fri May 8 15:53:26 UTC 2020
Modified Files:
src/sys/dev: random.c
Log Message:
Simplify /dev/random without reference to entropy_depletion.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/sys/dev/random.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/dev/random.c
diff -u src/sys/dev/random.c:1.3 src/sys/dev/random.c:1.4
--- src/sys/dev/random.c:1.3 Thu May 7 19:05:51 2020
+++ src/sys/dev/random.c Fri May 8 15:53:26 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: random.c,v 1.3 2020/05/07 19:05:51 riastradh Exp $ */
+/* $NetBSD: random.c,v 1.4 2020/05/08 15:53:26 riastradh Exp $ */
/*-
* Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -47,7 +47,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: random.c,v 1.3 2020/05/07 19:05:51 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: random.c,v 1.4 2020/05/08 15:53:26 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -275,11 +275,10 @@ random_read(dev_t dev, struct uio *uio,
n = MIN(n, RANDOM_BUFSIZE);
/*
- * If we're `depleting' and this is /dev/random, clamp
- * to the smaller of the entropy capacity or the seed.
+ * Clamp /dev/random output to the entropy capacity and
+ * seed size. Programs can't rely on long reads.
*/
- if (__predict_false(atomic_load_relaxed(&entropy_depletion)) &&
- minor(dev) == RND_DEV_RANDOM) {
+ if (minor(dev) == RND_DEV_RANDOM) {
n = MIN(n, ENTROPY_CAPACITY);
n = MIN(n, sizeof seed);
/*
@@ -343,14 +342,11 @@ random_read(dev_t dev, struct uio *uio,
break;
/*
- * If we're `depleting' and this is /dev/random, stop
- * here, return what we have, and force the next read
- * to reseed. Could grab more from the pool if
- * possible without blocking, but that's more
- * work.
+ * If this is /dev/random, stop here, return what we
+ * have, and force the next read to reseed. Programs
+ * can't rely on /dev/random for long reads.
*/
- if (__predict_false(atomic_load_relaxed(&entropy_depletion)) &&
- minor(dev) == RND_DEV_RANDOM) {
+ if (minor(dev) == RND_DEV_RANDOM) {
error = 0;
break;
}
