From: "Theodore Ts'o" <tytso@mit.edu>
To: torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: /dev/random changes for 3.13
Date: Wed, 13 Nov 2013 21:03:32 -0500 [thread overview]
Message-ID: <20131114020332.GA10961@thunk.org> (raw)
The following changes since commit 6e4664525b1db28f8c4e1130957f70a94c19213e:
Linux 3.11 (2013-09-02 13:46:10 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random.git tags/random_for_linus
for you to fetch changes up to 392a546dc8368d1745f9891ef3f8f7c380de8650:
random: add debugging code to detect early use of get_random_bytes() (2013-11-03 18:24:08 -0500)
----------------------------------------------------------------
The /dev/random changes for 3.13 including a number of improvements in
the following areas: performance, avoiding waste of entropy, better
tracking of entropy estimates, support for non-x86 platforms that have
a register which can't be used for fine-grained timekeeping, but which
might be good enough for the random driver.
Also add some printk's so that we can see how quickly /dev/urandom can
get initialized, and when programs try to use /dev/urandom before it
is fully initialized (since this could be a security issue). This
shouldn't be an issue on x86 desktop/laptops --- a test on my Lenovo
T430s laptop shows that /dev/urandom is getting fully initialized
approximately two seconds before the root file system is mounted
read/write --- this may be an issue with ARM and MIPS embedded/mobile
systems, though. These printk's will be a useful canary before
potentially adding a future change to start blocking processes which
try to read from /dev/urandom before it is initialized, which is
something FreeBSD does already for security reasons, and which
security folks have been agitating for Linux to also adopt.
----------------------------------------------------------------
H. Peter Anvin (3):
random: statically compute poolbitshift, poolbytes, poolbits
random: allow fractional bits to be tracked
random: account for entropy loss due to overwrites
Theodore Ts'o (17):
random: run random_int_secret_init() run after all late_initcalls
random: allow architectures to optionally define random_get_entropy()
random: mix in architectural randomness earlier in extract_buf()
random: fix the tracepoint for get_random_bytes(_arch)
random: optimize spinlock use in add_device_randomness()
random: optimize the entropy_store structure
random: cap the rate which the /dev/urandom pool gets reseeded
random: speed up the fast_mix function by a factor of four
random: adjust the generator polynomials in the mixing function slightly
random: drop trickle mode
random: push extra entropy to the output pools
random: convert DEBUG_ENT to tracepoints
random: make add_timer_randomness() fill the nonblocking pool first
random: printk notifications for urandom pool initialization
random: don't zap entropy count in rand_initialize()
random: initialize the last_time field in struct timer_rand_state
random: add debugging code to detect early use of get_random_bytes()
drivers/char/random.c | 652 ++++++++++++++++++++++++++++++++-------------------
include/linux/random.h | 1 +
include/linux/timex.h | 14 ++
include/trace/events/random.h | 183 ++++++++++++++-
init/main.c | 2 +
5 files changed, 608 insertions(+), 244 deletions(-)
next reply other threads:[~2013-11-14 2:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 2:03 Theodore Ts'o [this message]
2013-11-14 6:52 ` /dev/random changes for 3.13 Theodore Ts'o
2013-11-15 21:58 ` Linus Torvalds
2013-11-16 0:33 ` Theodore Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131114020332.GA10961@thunk.org \
--to=tytso@mit.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.