Commit Graph

11 Commits

Author SHA1 Message Date
Conrad Meyer
9b31a8daad virtio_random(4): Drop no longer needed unload kludge
After r356194, source deregistration no longer races with concurrent use.

Reviewed by:	bryanv, markm
Differential Revision:	https://reviews.freebsd.org/D22490
2019-12-30 01:40:59 +00:00
Conrad Meyer
0f6040f03e virtio(4): Add PNP match metadata for virtio devices
Register MODULE_PNP_INFO for virtio devices using the newbus PNP information
provided by the previous commit.  Matching can be quite simple; existing
probe routines only matched on bus (implicit) and device_type.  The same
matching criteria are retained exactly, but is now also available to
devmatch(8).

Reviewed by:	bryanv, markj; imp (earlier version)
Differential Revision:	https://reviews.freebsd.org/D20407
2019-06-04 02:37:11 +00:00
Conrad Meyer
ad5979f7da virtio_random(4): Fix random(4) integration
random(4) masks unregistered entropy sources.  Prior to this revision,
virtio_random(4) did not correctly register a random_source and did not
function as a source of entropy.

Random source registration for loadable pure sources requires registering a
poll callback, which is invoked periodically by random(4)'s harvestq
kthread.  The periodic poll makes virtio_random(4)'s periodic entropy
collection redundant, so this revision removes the callout.

The current random source API is somewhat limiting, so simply fail to attach
any virtio_random devices if one is already registered as a source.  This
scenario is expected to be uncommon.

While here, handle the possibility of short reads from the hypervisor random
device gracefully / correctly.  It is not clear why a hypervisor would
return a short read or if it is allowed by spec, but we may as well handle
it.

Reviewed by:	bryanv (earlier version), markm
Security:	yes (note: many other "pure" random sources remain broken)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D20419
2019-06-04 00:01:37 +00:00
Conrad Meyer
5ca5dfe938 random(4): Fix RANDOM_LOADABLE build
I introduced an obvious compiler error in r346282, so this change fixes
that.

Unfortunately, RANDOM_LOADABLE isn't covered by our existing tinderbox, and
it seems like there were existing latent linking problems.  I believe these
were introduced on accident in r338324 during reduction of the boolean
expression(s) adjacent to randomdev.c and hash.c.  It seems the
RANDOM_LOADABLE build breakage has gone unnoticed for nine months.

This change correctly annotates randomdev.c and hash.c with !random_loadable
to match the pre-r338324 logic; and additionally updates the HWRNG drivers
in MD 'files.*', which depend on random_device symbols, with
!random_loadable (it is invalid for the kernel to depend on symbols from a
module).

(The expression for both randomdev.c and hash.c was the same, prior to
r338324: "optional random random_yarrow | random !random_yarrow
!random_loadable".  I.e., "random && (yarrow || !loadable)."  When Yarrow
was removed ("yarrow := False"), the expression was incorrectly reduced to
"optional random" when it should have retained "random && !loadable".)

Additionally, I discovered that virtio_random was missing a MODULE_DEPEND on
random_device, which breaks kld load/link of the driver on RANDOM_LOADABLE
kernels.  Address that issue as well.

PR:		238223
Reported by:	Eir Nym <eirnym AT gmail.com>
Reviewed by:	delphij, markm
Approved by:	secteam(delphij)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D20466
2019-06-01 01:22:21 +00:00
Conrad Meyer
af8f74ad14 virtio_random(4): Remove unneeded reference to device
The device_t always references the softc, so we can pass the device and
obtain the softc instead of the other way around.
2019-05-27 00:55:46 +00:00
Mark Murray
19fa89e938 Remove the Yarrow PRNG algorithm option in accordance with due notice
given in random(4).

This includes updating of the relevant man pages, and no-longer-used
harvesting parameters.

Ensure that the pseudo-unit-test still does something useful, now also
with the "other" algorithm instead of Yarrow.

PR:		230870
Reviewed by:	cem
Approved by:	so(delphij,gtetlow)
Approved by:	re(marius)
Differential Revision:	https://reviews.freebsd.org/D16898
2018-08-26 12:51:46 +00:00
Pedro F. Giffuni
718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00
Mark Murray
d1b06863fb Huge cleanup of random(4) code.
* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
  neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
  random(4) device in the kernel, and the KERN_ARND sysctl will
  return nothing. With RANDOM_DUMMY there will be a random(4) that
  always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
  through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
  suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
  This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
  there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
  behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
  (direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
  weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
  weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
  when the dust settles.
- Use macros for locks.
- Fix comments.

* src/share/man/...
- Update the man pages.

* src/etc/...
- The startup/shutdown work is done in D2924.

* src/UPDATING
- Add UPDATING announcement.

* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.

* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.

* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.

* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
  selection is the way to go.

* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.

* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.

* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
  that instead. All that is needed here is N=0, N++, N==0, and some
  localised trickery is used to manufacture a 128-bit 0ULLL.

* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
  now the test will do a basic check of compressibility. Clairvoyant
  talent is still a good idea.
- This is still a long way off a proper unit test.

* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])

* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.

Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)
2015-06-30 17:00:45 +00:00
Jung-uk Kim
fd90e2ed54 CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head.  However, it is continuously misused as the mpsafe argument
for callout_init(9).  Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision:	https://reviews.freebsd.org/D2613
Reviewed by:	jhb
MFC after:	2 weeks
2015-05-22 17:05:21 +00:00
Bryan Venteicher
afd5e40ee0 Wait for the callout to finish before unloading the module
MFC after:	3 days
2014-04-24 05:04:54 +00:00
Bryan Venteicher
10c4018057 Add very simple virtio_random(4) driver to harvest entropy from host
Reviewed by:	markm (random bits only)
2014-01-18 06:14:38 +00:00