FreeBSD src
Go to file
Adrian Chadd 03475bd01a [net80211] remove node scan lock / generation number + fix few LORs
Drop scan generation number and node table scan lock - the only place
where ni_scangen is checked is in ieee80211_timeout_stations() (and it
is used to prevent duplicate checking of the same node); node scan lock
protects only this variable + node table scan generation number.

This will fix (at least) next LOR (hostap mode):

lock order reversal:
1st 0xc175f84c urtwm0_scan_loc (urtwm0_scan_loc) @ /usr/src/sys/modules/wlan/../../net80211/ieee80211_node.c:2019
2nd 0xc175e018 urtwm0_com_lock (urtwm0_com_lock) @ /usr/src/sys/modules/wlan/../../net80211/ieee80211_node.c:2693
stack backtrace:
#0 0xa070d1c5 at witness_debugger+0x75
#1 0xa070d0f6 at witness_checkorder+0xd46
#2 0xa0694cce at __mtx_lock_flags+0x9e
#3 0xb03ad9ef at ieee80211_node_leave+0x12f
#4 0xb03afd13 at ieee80211_timeout_stations+0x483
#5 0xb03aa1c2 at ieee80211_node_timeout+0x42
#6 0xa06c6fa1 at softclock_call_cc+0x1e1
#7 0xa06c7518 at softclock+0xc8
#8 0xa06789ae at intr_event_execute_handlers+0x8e
#9 0xa0678fa0 at ithread_loop+0x90
#10 0xa0675fbe at fork_exit+0x7e
#11 0xa08af910 at fork_trampoline+0x8

In addition to the above:

* switch to ieee80211_iterate_nodes();
* do not assert that node table lock is held, while calling node_age();
  that's not really needed (there are no resources, which can be protected
  by this lock) + this fixes LOR/deadlock between ieee80211_timeout_stations()
  and ieee80211_set_tim() (easy to reproduce in HOSTAP mode while
  sending something to an STA with enabled power management).

Tested:

* (avos) urtwn0, hostap mode
* (adrian) AR9380, STA mode
* (adrian) AR9380, AR9331, AR9580, hostap mode

Notes:

* This changes the net80211 internals, so you have to recompile all of it
  and the wifi drivers.

Submitted by:	avos
Approved by:	re (delphij)
Differential Revision:	https://reviews.freebsd.org/D6833
2016-06-19 07:31:02 +00:00
bin WITH_META_MODE: Fix bin/csh rebuilding tc.const.h 2016-06-14 16:19:49 +00:00
cddl Fix missing space in mandoc syntax 2016-06-01 06:18:34 +00:00
contrib Import ClangFormat.cpp from ^/vendor/clang/clang-release_380-r262564 2016-06-17 16:44:31 +00:00
crypto Add blacklist support to sshd 2016-06-07 16:18:09 +00:00
etc Commit the bits of nda that were missed. This should fix the build. 2016-06-10 06:04:53 +00:00
gnu WITH_META_MODE: Don't expect a .meta file for side-effect generated files. 2016-06-15 23:57:53 +00:00
include Commit the bits of nda that were missed. This should fix the build. 2016-06-10 06:04:53 +00:00
kerberos5 DIRDEPS_BUILD: Update dependencies 2016-06-14 16:55:05 +00:00
lib Add clang-format under WITH_CLANG_EXTRAS. 2016-06-17 16:46:58 +00:00
libexec DIRDEPS_BUILD: Update dependencies 2016-06-14 16:55:05 +00:00
release Note ipfilter support in blacklist-helper script in relnotes 2016-06-17 16:34:25 +00:00
rescue DIRDEPS_BUILD: Fix and hookup rescue/rescue to the build. 2016-05-26 23:20:40 +00:00
sbin pf: Filter on and set vlan PCP values 2016-06-17 18:21:55 +00:00
secure DIRDEPS_BUILD: Update dependencies 2016-06-14 16:55:05 +00:00
share - Prefer to use %d over %e where the day of the month should be zero 2016-06-19 03:44:32 +00:00
sys [net80211] remove node scan lock / generation number + fix few LORs 2016-06-19 07:31:02 +00:00
targets Add clang-format under WITH_CLANG_EXTRAS. 2016-06-17 16:46:58 +00:00
tests Always create loopback routes on every fib 2016-05-27 22:40:40 +00:00
tools - Prefer to use %d over %e where the day of the month should be zero 2016-06-19 03:44:32 +00:00
usr.bin mkimg: bump version to 20151211 after r292082 2016-06-17 18:49:42 +00:00
usr.sbin Add bsdconfig wifi' (aka wireless' or `wlan') module 2016-06-16 21:14:25 +00:00
.arcconfig Remove project.name which is a product of a bygone era. 2016-04-21 04:33:07 +00:00
.arclint phabricator related changes: 2015-04-20 20:33:22 +00:00
COPYRIGHT Bump copyright year. 2015-12-31 11:21:45 +00:00
LOCKS Explicitly require Security Officer's approval for kernel PRNG bits. 2013-09-17 14:19:05 +00:00
MAINTAINERS Add myself to MAINTAINERS. 2016-03-14 16:27:43 +00:00
Makefile WITH_META_MODE: Whitelist 'make kernel' and 'make world'. 2016-06-15 23:58:06 +00:00
Makefile.inc1 Fix native powerpc64 build of lib32 with in-tree GCC. 2016-06-15 23:58:03 +00:00
Makefile.libcompat Fix native powerpc64 build of lib32 with in-tree GCC. 2016-06-15 23:58:03 +00:00
ObsoleteFiles.inc Replace _pam_verbose_error() with a macro. This was the last difference 2016-06-08 11:47:19 +00:00
README README: remove nonexistent 'games' directory. 2016-05-18 10:43:13 +00:00
UPDATING Fix typo from r300880 2016-05-27 22:44:33 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree.  See build(7)
and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The `buildkernel` and `installkernel` targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process.  See build(7), config(8),
and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
for more information.

Note: If you want to build and install the kernel with the
`buildkernel` and `installkernel` targets, you might need to build
world before.  More information is available in the handbook.

The kernel configuration files reside in the sys/<arch>/conf
sub-directory.  GENERIC is the default configuration used in release builds.
NOTES contains entries and documentation for all possible
devices, not just those commonly used.


Source Roadmap:
---------------

bin		System/user commands.

cddl		Various commands and libraries under the Common Development
		and Distribution License.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tests		Regression tests which can be run by Kyua.  See tests/README
		for additional information.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html