From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg KH <gregkh@linuxfoundation.org>,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk, "Theodore Tso" <tytso@mit.edu>
Subject: [ 25/44] random: use the arch-specific rng in xfer_secondary_pool
Date: Mon, 13 Aug 2012 15:02:32 -0700 [thread overview]
Message-ID: <20120813220144.347219200@linuxfoundation.org> (raw)
In-Reply-To: <20120813220142.113186818@linuxfoundation.org>
From: Greg KH <gregkh@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Theodore Ts'o <tytso@mit.edu>
commit e6d4947b12e8ad947add1032dd754803c6004824 upstream.
If the CPU supports a hardware random number generator, use it in
xfer_secondary_pool(), where it will significantly improve things and
where we can afford it.
Also, remove the use of the arch-specific rng in
add_timer_randomness(), since the call is significantly slower than
get_cycles(), and we're much better off using it in
xfer_secondary_pool() anyway.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/char/random.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -254,6 +254,7 @@
#include <linux/cryptohash.h>
#include <linux/fips.h>
#include <linux/ptrace.h>
+#include <linux/kmemcheck.h>
#ifdef CONFIG_GENERIC_HARDIRQS
# include <linux/irq.h>
@@ -702,11 +703,7 @@ static void add_timer_randomness(struct
goto out;
sample.jiffies = jiffies;
-
- /* Use arch random value, fall back to cycles */
- if (!arch_get_random_int(&sample.cycles))
- sample.cycles = get_cycles();
-
+ sample.cycles = get_cycles();
sample.num = num;
mix_pool_bytes(&input_pool, &sample, sizeof(sample), NULL);
@@ -838,7 +835,11 @@ static ssize_t extract_entropy(struct en
*/
static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
{
- __u32 tmp[OUTPUT_POOL_WORDS];
+ union {
+ __u32 tmp[OUTPUT_POOL_WORDS];
+ long hwrand[4];
+ } u;
+ int i;
if (r->pull && r->entropy_count < nbytes * 8 &&
r->entropy_count < r->poolinfo->POOLBITS) {
@@ -849,17 +850,23 @@ static void xfer_secondary_pool(struct e
/* pull at least as many as BYTES as wakeup BITS */
bytes = max_t(int, bytes, random_read_wakeup_thresh / 8);
/* but never more than the buffer size */
- bytes = min_t(int, bytes, sizeof(tmp));
+ bytes = min_t(int, bytes, sizeof(u.tmp));
DEBUG_ENT("going to reseed %s with %d bits "
"(%d of %d requested)\n",
r->name, bytes * 8, nbytes * 8, r->entropy_count);
- bytes = extract_entropy(r->pull, tmp, bytes,
+ bytes = extract_entropy(r->pull, u.tmp, bytes,
random_read_wakeup_thresh / 8, rsvd);
- mix_pool_bytes(r, tmp, bytes, NULL);
+ mix_pool_bytes(r, u.tmp, bytes, NULL);
credit_entropy_bits(r, bytes*8);
}
+ kmemcheck_mark_initialized(&u.hwrand, sizeof(u.hwrand));
+ for (i = 0; i < 4; i++)
+ if (arch_get_random_long(&u.hwrand[i]))
+ break;
+ if (i)
+ mix_pool_bytes(r, &u.hwrand, sizeof(u.hwrand), 0);
}
/*
next prev parent reply other threads:[~2012-08-13 22:05 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-13 22:02 [ 00/44] 3.0.41-stable review Greg Kroah-Hartman
2012-08-13 22:02 ` [ 01/44] [IA64] Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts Greg Kroah-Hartman
2012-08-13 22:02 ` [ 02/44] SUNRPC: return negative value in case rpcbind client creation error Greg Kroah-Hartman
2012-08-13 22:02 ` [ 03/44] nilfs2: fix deadlock issue between chcp and thaw ioctls Greg Kroah-Hartman
2012-08-13 22:02 ` [ 04/44] pcdp: use early_ioremap/early_iounmap to access pcdp table Greg Kroah-Hartman
2012-08-13 22:02 ` [ 05/44] mm: fix wrong argument of migrate_huge_pages() in soft_offline_huge_page() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 06/44] ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+ Greg Kroah-Hartman
2012-08-15 14:02 ` Ben Hutchings
2012-08-13 22:02 ` [ 07/44] ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP Greg Kroah-Hartman
2012-08-14 20:01 ` Herton Ronaldo Krzesinski
2012-08-15 14:05 ` Greg Kroah-Hartman
2012-08-15 14:50 ` Herton Ronaldo Krzesinski
2012-08-13 22:02 ` [ 08/44] ARM: 7478/1: errata: extend workaround for erratum #720789 Greg Kroah-Hartman
2012-08-13 22:02 ` [ 09/44] ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT caches Greg Kroah-Hartman
2012-08-13 22:02 ` [ 10/44] ALSA: hda - remove quirk for Dell Vostro 1015 Greg Kroah-Hartman
2012-08-14 5:17 ` David Henningsson
2012-08-14 5:43 ` Takashi Iwai
2012-08-15 14:03 ` Greg Kroah-Hartman
2012-08-13 22:02 ` [ 11/44] mm: mmu_notifier: fix freed page still mapped in secondary MMU Greg Kroah-Hartman
2012-08-13 22:02 ` [ 12/44] mac80211: cancel mesh path timer Greg Kroah-Hartman
2012-08-13 22:02 ` [ 13/44] x86, nops: Missing break resulting in incorrect selection on Intel Greg Kroah-Hartman
2012-08-13 22:02 ` [ 14/44] random: Add support for architectural random hooks Greg Kroah-Hartman
2012-08-13 22:02 ` [ 15/44] fix typo/thinko in get_random_bytes() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 16/44] random: Use arch_get_random_int instead of cycle counter if avail Greg Kroah-Hartman
2012-08-13 22:02 ` [ 17/44] random: Use arch-specific RNG to initialize the entropy store Greg Kroah-Hartman
2012-08-13 22:02 ` [ 18/44] random: Adjust the number of loops when initializing Greg Kroah-Hartman
2012-08-13 22:02 ` [ 19/44] drivers/char/random.c: fix boot id uniqueness race Greg Kroah-Hartman
2012-08-13 22:02 ` [ 20/44] random: make add_interrupt_randomness() do something sane Greg Kroah-Hartman
2012-08-13 22:02 ` [ 21/44] random: use lockless techniques in the interrupt path Greg Kroah-Hartman
2012-08-13 22:02 ` [ 22/44] random: create add_device_randomness() interface Greg Kroah-Hartman
2012-08-13 22:02 ` [ 23/44] usb: feed USB device information to the /dev/random driver Greg Kroah-Hartman
2012-08-13 22:02 ` [ 24/44] net: feed /dev/random with the MAC address when registering a device Greg Kroah-Hartman
2012-08-13 22:02 ` Greg Kroah-Hartman [this message]
2012-08-13 22:02 ` [ 26/44] random: add new get_random_bytes_arch() function Greg Kroah-Hartman
2012-08-13 22:02 ` [ 27/44] random: add tracepoints for easier debugging and verification Greg Kroah-Hartman
2012-08-13 22:02 ` [ 28/44] MAINTAINERS: Theodore Tso is taking over the random driver Greg Kroah-Hartman
2012-08-13 22:02 ` [ 29/44] rtc: wm831x: Feed the write counter into device_add_randomness() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 30/44] mfd: wm831x: Feed the device UUID " Greg Kroah-Hartman
2012-08-13 22:02 ` [ 31/44] random: remove rand_initialize_irq() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 32/44] random: Add comment to random_initialize() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 33/44] dmi: Feed DMI table to /dev/random driver Greg Kroah-Hartman
2012-08-13 22:02 ` [ 34/44] random: mix in architectural randomness in extract_buf() Greg Kroah-Hartman
2012-08-13 22:02 ` [ 35/44] x86, microcode: microcode_core.c simple_strtoul cleanup Greg Kroah-Hartman
2012-08-13 22:02 ` [ 36/44] x86, microcode: Sanitize per-cpu microcode reloading interface Greg Kroah-Hartman
2012-08-15 0:26 ` Henrique de Moraes Holschuh
2012-08-15 14:06 ` Greg Kroah-Hartman
2012-08-15 16:30 ` Henrique de Moraes Holschuh
2012-08-15 18:26 ` Greg Kroah-Hartman
2012-08-13 22:02 ` [ 37/44] mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables Greg Kroah-Hartman
2012-08-13 22:02 ` [ 38/44] ARM: mxs: Remove MMAP_MIN_ADDR setting from mxs_defconfig Greg Kroah-Hartman
2012-08-13 22:02 ` [ 39/44] ARM: pxa: remove irq_to_gpio from ezx-pcap driver Greg Kroah-Hartman
2012-08-13 22:02 ` [ 40/44] cfg80211: process pending events when unregistering net device Greg Kroah-Hartman
2012-08-13 22:02 ` [ 41/44] cfg80211: fix interface combinations check for ADHOC(IBSS) Greg Kroah-Hartman
2012-08-13 22:02 ` [ 42/44] e1000e: NIC goes up and immediately goes down Greg Kroah-Hartman
2012-08-13 22:02 ` [ 43/44] Input: wacom - Bamboo One 1024 pressure fix Greg Kroah-Hartman
2012-08-13 22:02 ` [ 44/44] rt61pci: fix NULL pointer dereference in config_lna_gain Greg Kroah-Hartman
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