svn commit: r287023 - in head: share/man/man4 sys/conf sys/dev/random sys/sys sys/vm
Mark Murray
markm at FreeBSD.org
Sat Aug 22 12:59:09 UTC 2015
Author: markm
Date: Sat Aug 22 12:59:05 2015
New Revision: 287023
URL: https://svnweb.freebsd.org/changeset/base/287023
Log:
Make the UMA harvesting go away completely if not wanted. Default to "not wanted".
Provide and document the RANDOM_ENABLE_UMA option.
Change RANDOM_FAST to RANDOM_UMA to clarify the harvesting.
Remove RANDOM_DEBUG option, replace with SDT probes. These will be of
use to folks measuring the harvesting effect when deciding whether to
use RANDOM_ENABLE_UMA.
Requested by: scottl and others.
Approved by: so (/dev/random blanket)
Differential Revision: https://reviews.freebsd.org/D3197
Modified:
head/share/man/man4/random.4
head/sys/conf/NOTES
head/sys/conf/options
head/sys/dev/random/build.sh
head/sys/dev/random/fortuna.c
head/sys/dev/random/random_harvestq.c
head/sys/dev/random/unit_test.c
head/sys/dev/random/yarrow.c
head/sys/sys/random.h
head/sys/vm/uma_core.c
Modified: head/share/man/man4/random.4
==============================================================================
--- head/share/man/man4/random.4 Sat Aug 22 07:45:49 2015 (r287022)
+++ head/share/man/man4/random.4 Sat Aug 22 12:59:05 2015 (r287023)
@@ -32,6 +32,7 @@
.Sh SYNOPSIS
.Cd "device random"
.Cd "options RANDOM_LOADABLE"
+.Cd "options RANDOM_ENABLE_UMA"
.Sh DESCRIPTION
The
.Nm
@@ -177,6 +178,24 @@ must be locked against
load and unload events,
and also must be indirect calls
to allow for removal.
+.Pp
+When
+.Cd "options RANDOM_ENABLE_UMA"
+is used,
+the
+.Pa /dev/random
+device will obtain entropy
+from the zone allocator.
+This is potentially very high rate,
+and if so will be of questionable use.
+If this is the case,
+use of this option
+is not recommended.
+Determining this is not trivial,
+so experimenting and measurement
+using tools such as
+.Xr dtrace 1
+will be required.
.Sh RANDOMNESS
The use of randomness in the field of computing
is a rather subtle issue because randomness means
Modified: head/sys/conf/NOTES
==============================================================================
--- head/sys/conf/NOTES Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/conf/NOTES Sat Aug 22 12:59:05 2015 (r287023)
@@ -2985,8 +2985,10 @@ options MAXFILES=999
#options RANDOM_YARROW # Yarrow CSPRNG (old default)
#options RANDOM_LOADABLE # Allow the algorithm to be loaded as
# a module.
-# For developers.
-options RANDOM_DEBUG # Extra debugging messages
+# Select this to allow high-rate but potentially expensive
+# harvesting of Slab-Allocator entropy. In very high-rate
+# situations the value of doing this is dubious at best.
+options RANDOM_ENABLE_UMA # slab allocator
# Module to enable execution of application via emulators like QEMU
options IMAGACT_BINMISC
Modified: head/sys/conf/options
==============================================================================
--- head/sys/conf/options Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/conf/options Sat Aug 22 12:59:05 2015 (r287023)
@@ -945,17 +945,16 @@ RACCT_DEFAULT_TO_DISABLED opt_global.h
RCTL opt_global.h
# Random number generator(s)
-# The DEBUG option is in global.h as the random harvesting
-# puts probes all over the place, and it makes little sense
-# to pollute these headers with an extra include.
-RANDOM_DEBUG opt_random.h
-# Which CSPRNG hashes we get.
+# Which CSPRNG hash we get.
# If Yarrow is not chosen, Fortuna is selected.
RANDOM_YARROW opt_random.h
# With this, no entropy processor is loaded, but the entropy
# harvesting infrastructure is present. This means an entropy
# processor may be loaded as a module.
RANDOM_LOADABLE opt_random.h
+# This turns on high-rate and potentially expensive harvesting in
+# the uma slab allocator.
+RANDOM_ENABLE_UMA opt_global.h
# Intel em(4) driver
EM_MULTIQUEUE opt_em.h
Modified: head/sys/dev/random/build.sh
==============================================================================
--- head/sys/dev/random/build.sh Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/dev/random/build.sh Sat Aug 22 12:59:05 2015 (r287023)
@@ -35,7 +35,7 @@
# <(sed -e 's/fortuna/wombat/g' \
# -e 's/FORTUNA/WOMBAT/g' fortuna.c) | less
#
-cc -g -O0 -pthread -DRANDOM_DEBUG \
+cc -g -O0 -pthread \
-I../.. -lstdthreads -Wall \
unit_test.c \
yarrow.c \
@@ -46,7 +46,7 @@ cc -g -O0 -pthread -DRANDOM_DEBUG \
../../crypto/sha2/sha256c.c \
-lz \
-o yunit_test
-cc -g -O0 -pthread -DRANDOM_DEBUG \
+cc -g -O0 -pthread \
-I../.. -lstdthreads -Wall \
unit_test.c \
fortuna.c \
Modified: head/sys/dev/random/fortuna.c
==============================================================================
--- head/sys/dev/random/fortuna.c Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/dev/random/fortuna.c Sat Aug 22 12:59:05 2015 (r287023)
@@ -43,6 +43,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/random.h>
+#include <sys/sdt.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
@@ -94,6 +95,11 @@ CTASSERT(RANDOM_FORTUNA_DEFPOOLSIZE <= R
CTASSERT(RANDOM_BLOCKSIZE == sizeof(uint128_t));
CTASSERT(RANDOM_KEYSIZE == 2*RANDOM_BLOCKSIZE);
+/* Probes for dtrace(1) */
+SDT_PROVIDER_DECLARE(random);
+SDT_PROVIDER_DEFINE(random);
+SDT_PROBE_DEFINE2(random, fortuna, event_processor, debug, "u_int", "struct fs_pool *");
+
/*
* This is the beastie that needs protecting. It contains all of the
* state that we are excited about. Exactly one is instantiated.
@@ -379,16 +385,7 @@ random_fortuna_pre_read(void)
} else
break;
}
-#ifdef RANDOM_DEBUG
- {
- u_int j;
-
- printf("random: reseedcount [%d]", fortuna_state.fs_reseedcount);
- for (j = 0; j < RANDOM_FORTUNA_NPOOLS; j++)
- printf(" %X", fortuna_state.fs_pool[j].fsp_length);
- printf("\n");
- }
-#endif
+ SDT_PROBE2(random, fortuna, event_processor, debug, fortuna_state.fs_reseedcount, fortuna_state.fs_pool);
/* FS&K */
random_fortuna_reseed_internal(s, i < RANDOM_FORTUNA_NPOOLS ? i + 1 : RANDOM_FORTUNA_NPOOLS);
/* Clean up and secure */
Modified: head/sys/dev/random/random_harvestq.c
==============================================================================
--- head/sys/dev/random/random_harvestq.c Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/dev/random/random_harvestq.c Sat Aug 22 12:59:05 2015 (r287023)
@@ -170,7 +170,7 @@ random_kthread(void)
/* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */
for (i = 0; i < RANDOM_ACCUM_MAX; i++) {
if (harvest_context.hc_entropy_fast_accumulator.buf[i]) {
- random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), 4, RANDOM_FAST);
+ random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), 4, RANDOM_UMA);
harvest_context.hc_entropy_fast_accumulator.buf[i] = 0;
}
}
@@ -261,7 +261,7 @@ static const char *(random_source_descr[
"INTERRUPT",
"SWI",
"FS_ATIME",
- "HIGH_PERFORMANCE", /* ENVIRONMENTAL_END */
+ "UMA", /* ENVIRONMENTAL_END */
"PURE_OCTEON",
"PURE_SAFE",
"PURE_GLXSB",
Modified: head/sys/dev/random/unit_test.c
==============================================================================
--- head/sys/dev/random/unit_test.c Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/dev/random/unit_test.c Sat Aug 22 12:59:05 2015 (r287023)
@@ -29,7 +29,7 @@
/*
Build this by going:
-cc -g -O0 -pthread -DRANDOM_<alg> -DRANDOM_DEBUG -I../.. -lstdthreads -Wall \
+cc -g -O0 -pthread -DRANDOM_<alg> -I../.. -lstdthreads -Wall \
unit_test.c \
yarrow.c \
fortuna.c \
Modified: head/sys/dev/random/yarrow.c
==============================================================================
--- head/sys/dev/random/yarrow.c Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/dev/random/yarrow.c Sat Aug 22 12:59:05 2015 (r287023)
@@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/random.h>
+#include <sys/sdt.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
@@ -77,6 +78,11 @@ __FBSDID("$FreeBSD$");
CTASSERT(RANDOM_BLOCKSIZE == sizeof(uint128_t));
CTASSERT(RANDOM_KEYSIZE == 2*RANDOM_BLOCKSIZE);
+/* Probes for dtrace(1) */
+SDT_PROVIDER_DECLARE(random);
+SDT_PROVIDER_DEFINE(random);
+SDT_PROBE_DEFINE3(random, yarrow, event_processor, debug, "boolean", "u_int", "struct ys_pool *");
+
/*
* This is the beastie that needs protecting. It contains all of the
* state that we are excited about. Exactly one is instantiated.
@@ -261,20 +267,7 @@ random_yarrow_reseed_internal(u_int fast
KASSERT(yarrow_state.ys_pool[RANDOM_YARROW_FAST].ysp_thresh > 0, ("random: Yarrow fast threshold = 0"));
KASSERT(yarrow_state.ys_pool[RANDOM_YARROW_SLOW].ysp_thresh > 0, ("random: Yarrow slow threshold = 0"));
RANDOM_RESEED_ASSERT_LOCK_OWNED();
-#ifdef RANDOM_DEBUG
- /* WARNING! This is dangerously tedious to do with mutexes held! */
- printf("random: %s ", __func__);
- printf("type/pool = %s ", fastslow == RANDOM_YARROW_FAST ? "RANDOM_YARROW_FAST" : "RANDOM_YARROW_SLOW");
- printf("seeded = %s\n", yarrow_state.ys_seeded ? "true" : "false");
- printf("random: fast - thresh %d,1 - ", yarrow_state.ys_pool[RANDOM_YARROW_FAST].ysp_thresh);
- for (i = RANDOM_START; i < ENTROPYSOURCE; i++)
- printf(" %d", yarrow_state.ys_pool[RANDOM_YARROW_FAST].ysp_source_bits[i]);
- printf("\n");
- printf("random: slow - thresh %d,%d - ", yarrow_state.ys_pool[RANDOM_YARROW_SLOW].ysp_thresh, yarrow_state.ys_slowoverthresh);
- for (i = RANDOM_START; i < ENTROPYSOURCE; i++)
- printf(" %d", yarrow_state.ys_pool[RANDOM_YARROW_SLOW].ysp_source_bits[i]);
- printf("\n");
-#endif
+ SDT_PROBE3(random, yarrow, event_processor, debug, yarrow_state.ys_seeded, yarrow_state.ys_slowoverthresh, yarrow_state.ys_pool);
/* 1. Hash the accumulated entropy into v[0] */
randomdev_hash_init(&context);
/* Feed the slow pool hash in if slow */
Modified: head/sys/sys/random.h
==============================================================================
--- head/sys/sys/random.h Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/sys/random.h Sat Aug 22 12:59:05 2015 (r287023)
@@ -1,5 +1,5 @@
/*-
- * Copyright (c) 2000-2013 Mark R. V. Murray
+ * Copyright (c) 2000-2015 Mark R. V. Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -35,9 +35,11 @@
#include "opt_random.h"
+#if !defined(KLD_MODULE)
#if defined(RANDOM_LOADABLE) && defined(RANDOM_YARROW)
#error "Cannot define both RANDOM_LOADABLE and RANDOM_YARROW"
#endif
+#endif
struct uio;
@@ -78,8 +80,8 @@ enum random_entropy_source {
RANDOM_INTERRUPT,
RANDOM_SWI,
RANDOM_FS_ATIME,
- RANDOM_FAST, /* Special!! Miscellaneous high performance stuff, like UMA/SLAB Allocator */
- RANDOM_ENVIRONMENTAL_END = RANDOM_FAST,
+ RANDOM_UMA, /* Special!! UMA/SLAB Allocator */
+ RANDOM_ENVIRONMENTAL_END = RANDOM_UMA,
/* Fast hardware random-number sources from here on. */
RANDOM_PURE_OCTEON,
RANDOM_PURE_SAFE,
@@ -105,6 +107,12 @@ void random_harvest_direct(const void *,
#define random_harvest_direct(a, b, c, d) do {} while (0)
#endif
+#if defined(RANDOM_ENABLE_UMA)
+#define random_harvest_fast_uma(a, b, c, d) random_harvest_fast(a, b, c, d)
+#else /* !defined(RANDOM_ENABLE_UMA) */
+#define random_harvest_fast_uma(a, b, c, d) do {} while (0)
+#endif /* defined(RANDOM_ENABLE_UMA) */
+
#endif /* _KERNEL */
#endif /* _SYS_RANDOM_H_ */
Modified: head/sys/vm/uma_core.c
==============================================================================
--- head/sys/vm/uma_core.c Sat Aug 22 07:45:49 2015 (r287022)
+++ head/sys/vm/uma_core.c Sat Aug 22 12:59:05 2015 (r287023)
@@ -2135,8 +2135,8 @@ uma_zalloc_arg(uma_zone_t zone, void *ud
int lockfail;
int cpu;
- /* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
- random_harvest_fast(&zone, sizeof(zone), 1, RANDOM_FAST);
+ /* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
+ random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
/* This is the fast path allocation */
#ifdef UMA_DEBUG_ALLOC_1
@@ -2677,8 +2677,8 @@ uma_zfree_arg(uma_zone_t zone, void *ite
int lockfail;
int cpu;
- /* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
- random_harvest_fast(&zone, sizeof(zone), 1, RANDOM_FAST);
+ /* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
+ random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
#ifdef UMA_DEBUG_ALLOC_1
printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
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