Commit Graph

224 Commits

Author SHA1 Message Date
hselasky
30eed323c8 Disallow TUN and TAP character device IOCTLs to modify the network device
type to any value. This can cause page faults and panics due to accessing
uninitialized fields in the "struct ifnet" which are specific to the network
device type.

MFC after:	1 week
Found by:	jau@iki.fi
PR:		223767
Sponsored by:	Mellanox Technologies
2017-11-29 09:40:11 +00:00
tuexen
513d614cdf Allow writing IP packets of length TUNMRU no matter if TUNSIFHEAD is set
or not.
2016-05-19 13:52:12 +00:00
markm
4637ff6821 * Address review (and add a bit myself).
- Tweek man page.
 - Remove all mention of RANDOM_FORTUNA. If the system owner wants YARROW or DUMMY, they ask for it, otherwise they get FORTUNA.
 - Tidy up headers a bit.
 - Tidy up declarations a bit.
 - Make static in a couple of places where needed.
 - Move Yarrow/Fortuna SYSINIT/SYSUNINIT to randomdev.c, moving us towards a single file where the algorithm context is used.
 - Get rid of random_*_process_buffer() functions. They were only used in one place each, and are better subsumed into those places.
 - Remove *_post_read() functions as they are stubs everywhere.
 - Assert against buffer size illegalities.
 - Clean up some silly code in the randomdev_read() routine.
 - Make the harvesting more consistent.
 - Make some requested argument name changes.
 - Tidy up and clarify a few comments.
 - Make some requested comment changes.
 - Make some requested macro changes.

* NOTE: the thing calling itself a 'unit test' is not yet a proper
  unit test, but it helps me ensure things work. It may be a proper
  unit test at some time in the future, but for now please don't make
  any assumptions or hold any expectations.

Differential Revision:	https://reviews.freebsd.org/D2025
Approved by:	so (/dev/random blanket)
2015-07-12 18:14:38 +00:00
markm
d586165577 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
markm
fce6747f55 This is the much-discussed major upgrade to the random(4) device, known to you all as /dev/random.
This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources.

The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people.

The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway.

Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to.

My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise.

My Nomex pants are on. Let the feedback commence!

Reviewed by:	trasz,des(partial),imp(partial?),rwatson(partial?)
Approved by:	so(des)
2014-10-30 21:21:53 +00:00
glebius
f2cafe032f Mechanically convert to if_inc_counter(). 2014-09-19 10:39:58 +00:00
hselasky
35b126e324 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
gjb
fc21f40567 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
hselasky
bd1ed65f0f Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
glebius
80e85e32a5 Remove AppleTalk support.
AppleTalk was a network transport protocol for Apple Macintosh devices
in 80s and then 90s. Starting with Mac OS X in 2000 the AppleTalk was
a legacy protocol and primary networking protocol is TCP/IP. The last
Mac OS X release to support AppleTalk happened in 2009. The same year
routing equipment vendors (namely Cisco) end their support.

Thus, AppleTalk won't be supported in FreeBSD 11.0-RELEASE.
2014-03-14 06:29:43 +00:00
glebius
d494babace Remove IPX support.
IPX was a network transport protocol in Novell's NetWare network operating
system from late 80s and then 90s. The NetWare itself switched to TCP/IP
as default transport in 1998. Later, in this century the Novell Open
Enterprise Server became successor of Novell NetWare. The last release
that claimed to still support IPX was OES 2 in 2007. Routing equipment
vendors (e.g. Cisco) discontinued support for IPX in 2011.

Thus, IPX won't be supported in FreeBSD 11.0-RELEASE.
2014-03-14 02:58:48 +00:00
melifaro
860ae05c24 Teach every SIOCGIFSTATUS provider to fill in ifs->ascii anyway.
Remove old bits of data concat for 'ascii' field.
Remove special SIOCGIFSTATUS handling from if.c (which Coverity yells at).

Reported by:	Coverity
Coverity CID:	1147174
MFC after:	2 weeks
2014-01-07 15:59:33 +00:00
adrian
900b03bfd2 Restore the entropy gathering from the m_data pointer value, not the
m_data payload.

After talking with markm/bde, this is what markm actually intended.
2013-11-02 15:13:02 +00:00
adrian
42bc4565be Convert the random entropy harvesting code to use a const void * pointer
rather than just void *.

Then, as part of this, convert a couple of mbuf m->m_data accesses
to mtod(m, const void *).

Reviewed by:	markm
Approved by:	security-officer (delphij)
Sponsored by:	Netflix, Inc.
2013-11-01 20:53:49 +00:00
glebius
ff6e113f1b The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-26 17:58:36 +00:00
markm
0643acd34d Debug run. This now works, except that the "live" sources haven't
been tested. With all sources turned on, this unlocks itself in
a couple of seconds! That is no my box, and there is no guarantee
that this will be the case everywhere.

* Cut debug prints.

* Use the same locks/mutexes all the way through.

* Be a tad more conservative about entropy estimates.
2013-10-06 12:40:32 +00:00
markm
b28953010e Snapshot. This passes the build test, but has not yet been finished or debugged.
Contains:

* Refactor the hardware RNG CPU instruction sources to feed into
the software mixer. This is unfinished. The actual harvesting needs
to be sorted out. Modified by me (see below).

* Remove 'frac' parameter from random_harvest(). This was never
used and adds extra code for no good reason.

* Remove device write entropy harvesting. This provided a weak
attack vector, was not very good at bootstrapping the device. To
follow will be a replacement explicit reseed knob.

* Separate out all the RANDOM_PURE sources into separate harvest
entities. This adds some secuity in the case where more than one
is present.

* Review all the code and fix anything obviously messy or inconsistent.
Address som review concerns while I'm here, like rename the pseudo-rng
to 'dummy'.

Submitted by:	Arthur Mesh <arthurmesh@gmail.com> (the first item)
2013-10-04 06:55:06 +00:00
markm
4655fd3ead MFC - tracking commit 2013-10-03 17:30:55 +00:00
glebius
3b39d8bc17 Clean up SIOCSIFDSTADDR usage from ifnet drivers. The ioctl itself is
extremely outdated, and I doubt that it was ever used for ifnet drivers.
It was used for AF_INET sockets in pre-FreeBSD time.

Approved by:	re (hrs)
Sponsored by:	Nginx, Inc.
2013-09-11 09:19:44 +00:00
markm
42ac52f951 Bring in some behind-the-scenes development, mainly By Arthur Mesh,
the rest by me.

o Namespace cleanup; the Yarrow name is now restricted to where it
  really applies; this is in anticipation of being augmented or
  replaced by Fortuna in the future. Fortuna is mentioned, but behind
  #if logic, and is ignorable for now.

o The harvest queue is pulled out into its own modules.

o Entropy harvesting is emproved, both by being made more conservative,
  and by separating (a bit!) the sources. Available entropy crumbs are
  marginally improved.

o Selection of sources is made clearer. With recent revelations,
  this will receive more work in the weeks and months to come.

Submitted by:	 Arthur Mesh (partly) <arthurmesh@gmail.com>
2013-09-07 14:15:13 +00:00
davide
5545e24af3 Don't clear the unused SI_CHEAPCLONE flag in tap_create()/tuncreate().
Reviewed by:	kib
2013-09-07 13:50:13 +00:00
markm
8a3bb03c25 Snapshot; Do some running repairs on entropy harvesting. More needs to follow. 2013-08-26 18:35:21 +00:00
markj
f82b0dd694 Add a missing module version declaration to if_tun(4).
PR:		181078
Submitted by:	Brandon Gooch <jamesbrandongooch@gmail.com>
MFC after:	1 week
2013-08-07 01:32:08 +00:00
glebius
b4bc270e8f Add const qualifier to the dst parameter of the ifnet if_output method. 2013-04-26 12:50:32 +00:00
glebius
8e20fa5ae9 Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually
2012-12-05 08:04:20 +00:00
glebius
05f24a6b77 Make the "struct if_clone" opaque to users of the cloning API. Users
now use function calls:

  if_clone_simple()
  if_clone_advanced()

to initialize a cloner, instead of macros that initialize if_clone
structure.

Discussed with:		brooks, bz, 1 year ago
2012-10-16 13:37:54 +00:00
kevlo
ceb08698f2 Revert previous commit...
Pointyhat to:	kevlo (myself)
2012-10-10 08:36:38 +00:00
kevlo
8747a46991 Prefer NULL over 0 for pointers 2012-10-09 08:27:40 +00:00
emaste
25f7973cf8 Remove an incorrect comment 2012-09-25 21:19:17 +00:00
ed
0c56cf839d Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
ed
832b15d289 Get rid of D_PSEUDO.
It seems the D_PSEUDO flag was meant to allow make_dev() to return NULL.
Nowadays we have a different interface for that; make_dev_p(). There's
no need to keep it there.

While there, remove an unneeded D_NEEDMINOR from the gpio driver.

Discussed with:	gonzo@ (gpio)
2011-10-18 08:09:44 +00:00
attilio
683d7a54ce Fix a deficiency in the selinfo interface:
If a selinfo object is recorded (via selrecord()) and then it is
quickly destroyed, with the waiters missing the opportunity to awake,
at the next iteration they will find the selinfo object destroyed,
causing a PF#.

That happens because the selinfo interface has no way to drain the
waiters before to destroy the registered selinfo object. Also this
race is quite rare to get in practice, because it would require a
selrecord(), a poll request by another thread and a quick destruction
of the selrecord()'ed selinfo object.

Fix this by adding the seldrain() routine which should be called
before to destroy the selinfo objects (in order to avoid such case),
and fix the present cases where it might have already been called.
Sometimes, the context is safe enough to prevent this type of race,
like it happens in device drivers which installs selinfo objects on
poll callbacks. There, the destruction of the selinfo object happens
at driver detach time, when all the filedescriptors should be already
closed, thus there cannot be a race.
For this case, mfi(4) device driver can be set as an example, as it
implements a full correct logic for preventing this from happening.

Sponsored by:	Sandvine Incorporated
Reported by:	rstone
Tested by:	pluknet
Reviewed by:	jhb, kib
Approved by:	re (bz)
MFC after:	3 weeks
2011-08-25 15:51:54 +00:00
bz
300a95bf76 Tag mbufs of all incoming frames or packets with the interface's FIB
setting (either default or if supported as set by SIOCSIFFIB, e.g.
from ifconfig).

Submitted by:	Alexander V. Chernikov (melifaro ipfw.ru)
Reviewed by:	julian
MFC after:	2 weeks
2011-07-03 16:08:38 +00:00
jhb
b37cdd581d Properly return an ENOBUFS error if a write to a tun(4) device fails
due to m_uiotombuf() failing.

While here, trim unneeded error handling related to tuninit() since it
can never fail.

Submitted by:	Martin Birgmeier  la5lbtyi aon at
Reviewed by:	glebius
MFC after:	1 week
2011-06-03 13:47:05 +00:00
yongari
0aab37190f Fix white space nits and style 2011-05-06 20:46:29 +00:00
yongari
b282e7aca8 Do not increment collision counter if transmit have failed.
Transmission error in tun(4) is queueing error(i.e. ENOBUFS) and it
has nothing to do with collision.

Reported by:	Zeus V Panchenko (zeus <> ibs dot dn dot ua)
2011-05-06 20:37:07 +00:00
bz
054f4fff23 Only hide the ifa and not the tp under #ifdef INET as the tp is needed
for locking evenwhen there is no INET.

MFC after:	3 days
2010-10-01 15:14:14 +00:00
jhb
b8914d3479 - Expand scope of tun/tap softc locks to cover more softc fields and
driver-maintained ifnet fields (such as if_drv_flags).
- Use soft locks as the mutex that protects each interface's knote list
  rather than using the global knote list lock.  Also, use the softc
  for kn_hook instead of the cdev.
- Use mtx_sleep() instead of tsleep() when blocking in the read routines.
  This fixes a lost wakeup race.
- Remove D_NEEDGIANT now that the cdevsw routines use the softc lock
  where locking is needed.
- Lock IFQ when calculating the result for FIONREAD in tap(4).  tun(4)
  already did this.
- Remove remaining spl calls.

Submitted by:	Marcin Cieslak  saper of saper|info (3)
MFC after:	2 weeks
2010-09-22 21:02:43 +00:00
qingli
4ff4954e4e Verify interface up status using its link state only
if the interface has such capability. The interface
capability flag indicates whether such capability
exists. This approach is much more backward compatible.
Physical device driver changes will be part of another
commit.

Also updated the ifconfig utility to show the LINKSTATE
capability if present.

Reviewed by:	rwatson, imp, juli
MFC after:	3 days
2010-03-16 17:59:12 +00:00
kib
f93a8fa5df In both if_tun and if_tap:
Do not do additional dev_ref() on the newly created interface in the
if_clone create method [1]. This reference is not needed and never
removed, causing struct cdevpriv leakage. Remove the setting of
SI_CHEAPCLONE flag as well, since it is unused.

For dev_clone handlers, create cdevs with the call make_dev_credf(MAKEDEV_REF)
instead of calling make_dev() and then dev_ref(), to avoid a race.

Call drain_dev_clone_events() at the module unload time after dev_clone
handler is deinstalled.

Submitted by:	Mikolaj Golub <to.my.trociny gmail com> [1]
MFC after:	1 week
2010-02-28 16:25:49 +00:00
rwatson
fb9ffed650 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00
rwatson
3dffb5419c Update if_stf and if_tun to use if_addr_rlock()/if_addr_runlock() rather
than IF_ADDR_LOCK()/IF_ADDR_UNLOCK() when iterating ifp->if_addrhead.

MFC after:	6 weeks
2009-06-26 00:45:20 +00:00
kib
a7a5954511 Change the type of uio_resid member of struct uio from int to ssize_t.
Note that this does not actually enable full-range i/o requests for
64 architectures, and is done now to update KBI only.

Tested by:	pho
Reviewed by:	jhb, bde (as part of the review of the bigger patch)
2009-06-25 18:46:30 +00:00
bz
48dc6805f8 Add explicit includes for jail.h to the files that need them and
remove the "hidden" one from vimage.h.
2009-06-17 15:01:01 +00:00
jamie
f950eed7d7 Get vnets from creds instead of threads where they're available, and from
passed threads instead of curthread.

Reviewed by:	zec, julian
Approved by:	bz (mentor)
2009-06-15 19:01:53 +00:00
kib
e1cb2941d4 Adapt vfs kqfilter to the shared vnode lock used by zfs write vop. Use
vnode interlock to protect the knote fields [1]. The locking assumes
that shared vnode lock is held, thus we get exclusive access to knote
either by exclusive vnode lock protection, or by shared vnode lock +
vnode interlock.

Do not use kl_locked() method to assert either lock ownership or the
fact that curthread does not own the lock. For shared locks, ownership
is not recorded, e.g. VOP_ISLOCKED can return LK_SHARED for the shared
lock not owned by curthread, causing false positives in kqueue subsystem
assertions about knlist lock.

Remove kl_locked method from knlist lock vector, and add two separate
assertion methods kl_assert_locked and kl_assert_unlocked, that are
supposed to use proper asserts. Change knlist_init accordingly.

Add convenience function knlist_init_mtx to reduce number of arguments
for typical knlist initialization.

Submitted by:	jhb [1]
Noted by:	jhb [2]
Reviewed by:	jhb
Tested by:	rnoland
2009-06-10 20:59:32 +00:00
rwatson
f4934662e5 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
rwatson
32db8063b4 Acquire interfce address list lock while walking the interface address
list during tun device initialization.

MFC after:	2 weeks
2009-04-20 23:25:38 +00:00
kmacy
24b38efdce Change if_output to take a struct route as its fourth argument in order
to allow passing a cached struct llentry * down to L2

Reviewed by:	rwatson
2009-04-16 20:30:28 +00:00
qingli
2a933d7a9b The "tun?" dev need not be opened at all. One is allowed to perform
the following operations, e.g.:
1) ifconfig tun0 create
2) ifconfig tun0 10.1.1.1 10.1.1.2
3) route add -net 192.103.54.0/24 -iface tun0
4) ifconfig tun0 destroy
If cv wait on the TUN_CLOSED flag, then the last operation (4) will
block forever.

Revert the previous changes and fix the mtx_unlock() leak.
2008-12-25 22:32:32 +00:00