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506,942 commits

Author SHA1 Message Date
Maxime Bizon
6f00a02296 bcm63xx_enet: add support for Broadcom BCM63xx integrated gigabit switch
Newer Broadcom BCM63xx SoCs: 6328, 6362 and 6368 have an integrated switch
which needs to be driven slightly differently from the traditional
external switches. This patch introduces changes in arch/mips/bcm63xx in order
to:

- register a bcm63xx_enetsw driver instead of bcm63xx_enet driver
- update DMA channels configuration & state RAM base addresses
- add a new platform data configuration knob to define the number of
  ports per switch/device and force link on some ports
- define the required switch registers

On the driver side, the following changes are required:

- the switch ports need to be polled to ensure the link is up and
  running and RX/TX can properly work
- basic switch configuration needs to be performed for the switch to
  forward packets to the CPU
- update the MIB counters since the integrated

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-10 14:28:28 -07:00
Maxime Bizon
0ae99b5fed bcm63xx_enet: split DMA channel register accesses
The current bcm63xx_enet driver always uses bcmenet_shared_base whenever
it needs to access DMA channel configuration space or access the DMA
channel state RAM. Split these register in 3 parts to be more accurate:

- global DMA configuration
- per DMA channel configuration space
- per DMA channel state RAM space

This is preliminary to support new chips where the global DMA
configuration remains the same, but there is a varying number of DMA
channels located at a different memory offset.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-10 14:28:27 -07:00
Maxime Bizon
7260aac974 bcm63xx_enet: implement reset autoneg ethtool callback
Implement the rset_nway ethtool callback which uses libphy generic
autonegotiation restart function.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-10 14:28:27 -07:00
Matthew Garrett
f8b8404337 Modify UEFI anti-bricking code
This patch reworks the UEFI anti-bricking code, including an effective
reversion of cc5a080c and 31ff2f20. It turns out that calling
QueryVariableInfo() from boot services results in some firmware
implementations jumping to physical addresses even after entering virtual
mode, so until we have 1:1 mappings for UEFI runtime space this isn't
going to work so well.

Reverting these gets us back to the situation where we'd refuse to create
variables on some systems because they classify deleted variables as "used"
until the firmware triggers a garbage collection run, which they won't do
until they reach a lower threshold. This results in it being impossible to
install a bootloader, which is unhelpful.

Feedback from Samsung indicates that the firmware doesn't need more than
5KB of storage space for its own purposes, so that seems like a reasonable
threshold. However, there's still no guarantee that a platform will attempt
garbage collection merely because it drops below this threshold. It seems
that this is often only triggered if an attempt to write generates a
genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to
create a variable larger than the remaining space. This should fail, but if
it somehow succeeds we can then immediately delete it.

I've tested this on the UEFI machines I have available, but I don't have
a Samsung and so can't verify that it avoids the bricking problem.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ]
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-06-10 21:59:37 +01:00
Paul E. McKenney
be77f87c00 Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD
cbnum.2013.06.10a: Apply simplifications stemming from the new callback
	numbering.

doc.2013.06.10a: Documentation updates.

fixes.2013.06.10a: Miscellaneous fixes.

srcu.2013.06.10a: Updates to SRCU.

tiny.2013.06.10a: Eliminate TINY_PREEMPT_RCU.
2013-06-10 13:46:44 -07:00
Paul E. McKenney
1496144469 rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs
TINY_RCU's reset_cpu_stall_ticks() and check_cpu_stalls() functions
are defined unconditionally, and are empty functions if CONFIG_RCU_TRACE
is disabled (which in turns disables detection of RCU CPU stalls).
This commit saves a few lines of source code by defining these functions
only if CONFIG_RCU_TRACE=y.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-06-10 13:45:53 -07:00
Paul E. McKenney
2439b696cb rcu: Shrink TINY_RCU by moving exit_rcu()
Now that TINY_PREEMPT_RCU is no more, exit_rcu() is always an empty
function.  But if TINY_RCU is going to have an empty function, it should
be in include/linux/rcutiny.h, where it does not bloat the kernel.
This commit therefore moves exit_rcu() out of kernel/rcupdate.c to
kernel/rcutree_plugin.h, and places a static inline empty function in
include/linux/rcutiny.h in order to shrink TINY_RCU a bit.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:52 -07:00
Paul E. McKenney
7807acdb6b rcu: Remove TINY_PREEMPT_RCU tracing documentation
Because TINY_PREEMPT_RCU is no more, this commit removes its tracing
formats from the documentation.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:52 -07:00
Paul E. McKenney
318bdcd959 rcu: Consolidate rcutiny_plugin.h ifdefs
This commit rearranges code in order to allow ifdefs to be consolidated
in kernel/rcutiny_plugin.h, simplifying the code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:52 -07:00
Paul E. McKenney
fa2b3b0a50 rcu: Remove rcu_preempt_note_context_switch()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_note_context_switch()
is now an empty function.  This commit therefore eliminates it by inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:52 -07:00
Paul E. McKenney
57f1801a11 rcu: Remove the CONFIG_TINY_RCU ifdefs in rcutiny.h
Now that CONFIG_TINY_PREEMPT_RCU is no more, this commit removes
the CONFIG_TINY_RCU ifdefs from include/linux/rcutiny.h in favor of
unconditionally compiling the CONFIG_TINY_RCU legs of those ifdefs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Moved removal of #else to "Remove TINY_PREEMPT_RCU" as
  suggested by Josh Triplett. ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:51 -07:00
Paul E. McKenney
4879c84daa rcu: Remove check_cpu_stall_preempt()
With the removal of CONFIG_TINY_PREEMPT_RCU, check_cpu_stall_preempt()
is now an empty function.  This commit therefore eliminates it by
inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:51 -07:00
Paul E. McKenney
9dc5ad3248 rcu: Simplify RCU_TINY RCU callback invocation
TINY_PREEMPT_RCU could use a kthread to handle RCU callback invocation,
which required an API to abstract kthread vs. softirq invocation.
Now that TINY_PREEMPT_RCU is no longer with us, this commit retires
this API in favor of direct use of the relevant softirq primitives.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:51 -07:00
Paul E. McKenney
58c4e69d43 rcu: Remove rcu_preempt_process_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_process_callbacks()
is now an empty function.  This commit therefore eliminates it by
inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:50 -07:00
Paul E. McKenney
47d65935a7 rcu: Remove rcu_preempt_remove_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_remove_callbacks()
is now an empty function.  This commit therefore eliminates it by
inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:50 -07:00
Paul E. McKenney
9acaac8ced rcu: Remove rcu_preempt_check_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_check_callbacks()
is now an empty function.  This commit therefore eliminates it by
inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:50 -07:00
Paul E. McKenney
221304e95e rcu: Remove show_tiny_preempt_stats()
With the removal of CONFIG_TINY_PREEMPT_RCU, show_tiny_preempt_stats()
is now an empty function.  This commit therefore eliminates it by
inlining it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:49 -07:00
Paul E. McKenney
127781d1ba rcu: Remove TINY_PREEMPT_RCU
TINY_PREEMPT_RCU adds significant code and complexity, but does not
offer commensurate benefits.  People currently using TINY_PREEMPT_RCU
can get much better memory footprint with TINY_RCU, or, if they really
need preemptible RCU, they can use TREE_PREEMPT_RCU with a relatively
minor degradation in memory footprint.  Please note that this move
has been widely publicized on LKML (https://lkml.org/lkml/2012/11/12/545)
and on LWN (http://lwn.net/Articles/541037/).

This commit therefore removes TINY_PREEMPT_RCU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated to eliminate #else in rcutiny.h as suggested by Josh ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:49 -07:00
Lai Jiangshan
505d6421bd powerpc,kvm: fix imbalance srcu_read_[un]lock()
At the point of up_out label in kvmppc_hv_setup_htab_rma(),
srcu read lock is still held.

We have to release it before return.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: kvm@vger.kernel.org
Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:26 -07:00
Paul E. McKenney
99f88919f8 rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw().
These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:45:25 -07:00
Paul E. McKenney
676c3dc203 rcu: Apply Dave Jones's NOCB Kconfig help feedback
The Kconfig help text for the RCU_NOCB_CPU_NONE, RCU_NOCB_CPU_ZERO,
and RCU_NOCB_CPU_ALL Kconfig options was unclear, so this commit
adds a bit more detail.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-06-10 13:44:57 -07:00
Paul E. McKenney
4982969d96 rcu: Merge adjacent identical ifdefs
Two ifdefs in kernel/rcupdate.c now have identical conditions with
nothing between them, so the commit merges them into a single ifdef.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:44:56 -07:00
Paul E. McKenney
026ad2835c rcu: Drive quiescent-state-forcing delay from HZ
Systems with HZ=100 can have slow bootup times due to the default
three-jiffy delays between quiescent-state forcing attempts.  This
commit therefore auto-tunes the RCU_JIFFIES_TILL_FORCE_QS value based
on the value of HZ.  However, this would break very large systems that
require more time between quiescent-state forcing attempts.  This
commit therefore also ups the default delay by one jiffy for each
256 CPUs that might be on the system (based off of nr_cpu_ids at
runtime, -not- NR_CPUS at build time).

Updated to collapse #ifdefs for RCU_JIFFIES_TILL_FORCE_QS into a
step-function definition as suggested by Josh Triplett.

Reported-by: Paul Mackerras <paulus@au1.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-06-10 13:44:56 -07:00
Paul E. McKenney
9a5739d73f rcu: Remove "Experimental" flags
After a release or two, features are no longer experimental.  Therefore,
this commit removes the "Experimental" tag from them.

Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:44:56 -07:00
Paul E. McKenney
f7bac9b85a kthread: Add kworker kthreads to OS-jitter documentation
The kworker workqueue kthreads can also contribute to OS jitter.
The amount of jitter depends on their use, so this commit adds
documentation on avoiding OS jitter due to workqueue use.

Reported-by: Jonathan Clairembault <jonathan.clairembault@novasparks.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:42:38 -07:00
Paul E. McKenney
ce5f4fc861 nohz_full: Document additional restrictions
This commit calls out the potential for slowing the tick even when there
are multiple runnable processes per CPU,  It also points out that current
mainlined version keeps the tick going on at least one CPU even when all
CPUs are otherwise idle.  Finally, it notes the need for a 1-HZ tick in
order to calculate CPU load, maintain sched average, compute CFS entity
vruntime, compute avenrun, and carry out load balancing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:42:38 -07:00
Paul E. McKenney
295fde89be nohz_full: Update based on Sedat Dilek review
Make it more clear that there are three options, and give hints as
to which of the three is most likely to be useful in different
situations.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:42:37 -07:00
Paul E. McKenney
05eb552bf5 rcu: Move redundant call to note_gp_changes() into called function
The __rcu_process_callbacks() invokes note_gp_changes() immediately
before invoking rcu_check_quiescent_state(), which conditionally
invokes that same function.  This commit therefore eliminates the
call to note_gp_changes() in __rcu_process_callbacks() in favor of
making unconditional to call from rcu_check_quiescent_state() to
note_gp_changes().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:44 -07:00
Paul E. McKenney
ce3d9c03d1 rcu: Inline trivial wrapper function rcu_start_gp_per_cpu()
Given the changes that introduce note_gp_change(), rcu_start_gp_per_cpu()
is now a trivial wrapper function with only one caller.  This commit
therefore inlines it into its sole call site.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:44 -07:00
Paul E. McKenney
63274cfb94 rcu: Eliminate check_for_new_grace_period() wrapper function
One of the calls to check_for_new_grace_period() is now redundant due to
an immediately preceding call to note_gp_changes().  Eliminating this
redundant call leaves a single caller, which is simpler if inlined.
This commit therefore eliminates the redundant call and inlines the
body of check_for_new_grace_period() into the single remaining call site.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:44 -07:00
Paul E. McKenney
ba9fbe955f rcu: Merge __rcu_process_gp_end() into __note_gp_changes()
This commit eliminates some duplicated code by merging
__rcu_process_gp_end() into __note_gp_changes().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:43 -07:00
Paul E. McKenney
470716fc04 rcu: Switch callers from rcu_process_gp_end() to note_gp_changes()
Because note_gp_changes() now incorporates rcu_process_gp_end() function,
this commit switches to the former and eliminates the latter.  In
addition, this commit changes external calls from __rcu_process_gp_end()
to __note_gp_changes().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:43 -07:00
Paul E. McKenney
efc151c33b rcu: Convert rcutree_plugin.h printk calls
This commit converts printk() calls to the corresponding pr_*() calls.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:42 -07:00
Paul E. McKenney
d34ea3221a rcu: Rename note_new_gpnum() to note_gp_changes()
Because note_new_gpnum() now also checks for the ends of old grace periods,
this commit changes its name to note_gp_changes().  Later commits will merge
rcu_process_gp_end() into note_gp_changes().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:42 -07:00
Paul E. McKenney
398ebe6000 rcu: Make __note_new_gpnum() check for ends of prior grace periods
The current implementation can detect the beginning of a new grace period
before noting the end of a previous grace period.  Although the current
implementation correctly handles this sort of nonsense, it would be
good to reduce RCU's state space by making such nonsense unnecessary,
which is now possible thanks to the fact that RCU's callback groups are
now numbered.

This commit therefore makes __note_new_gpnum() invoke
__rcu_process_gp_end() in order to note the ends of prior grace
periods before noting the beginnings of new grace periods.
Of course, this now means that note_new_gpnum() notes both the
beginnings and ends of grace periods, and could therefore be
used in place of rcu_process_gp_end().  But that is a job for
later commits.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:42 -07:00
Paul E. McKenney
6eaef633d7 rcu: Move code to apply callback-numbering simplifications
The addition of callback numbering allows combining the detection of the
ends of old grace periods and the beginnings of new grace periods.  This
commit moves code to set the stage for this combining.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:42 -07:00
Paul E. McKenney
d7f3e20739 rcu: Convert rcutree.c printk calls
This commit converts printk() calls to the corresponding pr_*() calls.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:39:41 -07:00
Paul E. McKenney
971394f389 rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration
In Steven Rostedt's words:

> I've been debugging the last couple of days why my tests have been
> locking up. One of my tracing tests, runs all available tracers. The
> lockup always happened with the mmiotrace, which is used to trace
> interactions between priority drivers and the kernel. But to do this
> easily, when the tracer gets registered, it disables all but the boot
> CPUs. The lockup always happened after it got done disabling the CPUs.
>
> Then I decided to try this:
>
> while :; do
> 	for i in 1 2 3; do
> 		echo 0 > /sys/devices/system/cpu/cpu$i/online
> 	done
> 	for i in 1 2 3; do
> 		echo 1 > /sys/devices/system/cpu/cpu$i/online
> 	done
> done
>
> Well, sure enough, that locked up too, with the same users. Doing a
> sysrq-w (showing all blocked tasks):
>
> [ 2991.344562]   task                        PC stack   pid father
> [ 2991.344562] rcu_preempt     D ffff88007986fdf8     0    10      2 0x00000000
> [ 2991.344562]  ffff88007986fc98 0000000000000002 ffff88007986fc48 0000000000000908
> [ 2991.344562]  ffff88007986c280 ffff88007986ffd8 ffff88007986ffd8 00000000001d3c80
> [ 2991.344562]  ffff880079248a40 ffff88007986c280 0000000000000000 00000000fffd4295
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81541750>] schedule_timeout+0xbc/0xf9
> [ 2991.344562]  [<ffffffff8154bec0>] ? ftrace_call+0x5/0x2f
> [ 2991.344562]  [<ffffffff81049513>] ? cascade+0xa8/0xa8
> [ 2991.344562]  [<ffffffff815417ab>] schedule_timeout_uninterruptible+0x1e/0x20
> [ 2991.344562]  [<ffffffff810c980c>] rcu_gp_kthread+0x502/0x94b
> [ 2991.344562]  [<ffffffff81062791>] ? __init_waitqueue_head+0x50/0x50
> [ 2991.344562]  [<ffffffff810c930a>] ? rcu_gp_fqs+0x64/0x64
> [ 2991.344562]  [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562]  [<ffffffff81091e31>] ? lock_release_holdtime.part.23+0x4e/0x55
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562]  [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] kworker/0:1     D ffffffff81a30680     0    47      2 0x00000000
> [ 2991.344562] Workqueue: events cpuset_hotplug_workfn
> [ 2991.344562]  ffff880078dbbb58 0000000000000002 0000000000000006 00000000000000d8
> [ 2991.344562]  ffff880078db8100 ffff880078dbbfd8 ffff880078dbbfd8 00000000001d3c80
> [ 2991.344562]  ffff8800779ca5c0 ffff880078db8100 ffffffff81541fcf 0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562]  [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562]  [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff810af7e6>] rebuild_sched_domains_locked+0x6e/0x3a8
> [ 2991.344562]  [<ffffffff810b0ec6>] rebuild_sched_domains+0x1c/0x2a
> [ 2991.344562]  [<ffffffff810b109b>] cpuset_hotplug_workfn+0x1c7/0x1d3
> [ 2991.344562]  [<ffffffff810b0ed9>] ? cpuset_hotplug_workfn+0x5/0x1d3
> [ 2991.344562]  [<ffffffff81058e07>] process_one_work+0x2d4/0x4d1
> [ 2991.344562]  [<ffffffff81058d3a>] ? process_one_work+0x207/0x4d1
> [ 2991.344562]  [<ffffffff8105964c>] worker_thread+0x2e7/0x3b5
> [ 2991.344562]  [<ffffffff81059365>] ? rescuer_thread+0x332/0x332
> [ 2991.344562]  [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562]  [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] bash            D ffffffff81a4aa80     0  2618   2612 0x10000000
> [ 2991.344562]  ffff8800379abb58 0000000000000002 0000000000000006 0000000000000c2c
> [ 2991.344562]  ffff880077fea140 ffff8800379abfd8 ffff8800379abfd8 00000000001d3c80
> [ 2991.344562]  ffff8800779ca5c0 ffff880077fea140 ffffffff81541fcf 0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562]  [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562]  [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff81091c99>] ? __lock_is_held+0x32/0x53
> [ 2991.344562]  [<ffffffff81548912>] notifier_call_chain+0x6b/0x98
> [ 2991.344562]  [<ffffffff810671fd>] __raw_notifier_call_chain+0xe/0x10
> [ 2991.344562]  [<ffffffff8103cf64>] __cpu_notify+0x20/0x32
> [ 2991.344562]  [<ffffffff8103cf8d>] cpu_notify_nofail+0x17/0x36
> [ 2991.344562]  [<ffffffff815225de>] _cpu_down+0x154/0x259
> [ 2991.344562]  [<ffffffff81522710>] cpu_down+0x2d/0x3a
> [ 2991.344562]  [<ffffffff81526351>] store_online+0x4e/0xe7
> [ 2991.344562]  [<ffffffff8134d764>] dev_attr_store+0x20/0x22
> [ 2991.344562]  [<ffffffff811b3c5f>] sysfs_write_file+0x108/0x144
> [ 2991.344562]  [<ffffffff8114c5ef>] vfs_write+0xfd/0x158
> [ 2991.344562]  [<ffffffff8114c928>] SyS_write+0x5c/0x83
> [ 2991.344562]  [<ffffffff8154c494>] tracesys+0xdd/0xe2
>
> As well as held locks:
>
> [ 3034.728033] Showing all locks held in the system:
> [ 3034.728033] 1 lock held by rcu_preempt/10:
> [ 3034.728033]  #0:  (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff810c9471>] rcu_gp_kthread+0x167/0x94b
> [ 3034.728033] 4 locks held by kworker/0:1/47:
> [ 3034.728033]  #0:  (events){.+.+.+}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033]  #1:  (cpuset_hotplug_work){+.+.+.}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033]  #2:  (cpuset_mutex){+.+.+.}, at: [<ffffffff810b0ec1>] rebuild_sched_domains+0x17/0x2a
> [ 3034.728033]  #3:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 3034.728033] 1 lock held by mingetty/2563:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2565:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2569:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2572:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2575:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 7 locks held by bash/2618:
> [ 3034.728033]  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff8114bc3f>] file_start_write+0x2a/0x2c
> [ 3034.728033]  #1:  (&buffer->mutex#2){+.+.+.}, at: [<ffffffff811b3b93>] sysfs_write_file+0x3c/0x144
> [ 3034.728033]  #2:  (s_active#54){.+.+.+}, at: [<ffffffff811b3c3e>] sysfs_write_file+0xe7/0x144
> [ 3034.728033]  #3:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff810217c2>] cpu_hotplug_driver_lock+0x17/0x19
> [ 3034.728033]  #4:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8103d196>] cpu_maps_update_begin+0x17/0x19
> [ 3034.728033]  #5:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103cfd8>] cpu_hotplug_begin+0x2c/0x6d
> [ 3034.728033]  #6:  (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 3034.728033] 1 lock held by bash/2980:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
>
> Things looked a little weird. Also, this is a deadlock that lockdep did
> not catch. But what we have here does not look like a circular lock
> issue:
>
> Bash is blocked in rcu_cpu_notify():
>
> 1961		/* Exclude any attempts to start a new grace period. */
> 1962		mutex_lock(&rsp->onoff_mutex);
>
>
> kworker is blocked in get_online_cpus(), which makes sense as we are
> currently taking down a CPU.
>
> But rcu_preempt is not blocked on anything. It is simply sleeping in
> rcu_gp_kthread (really rcu_gp_init) here:
>
> 1453	#ifdef CONFIG_PROVE_RCU_DELAY
> 1454			if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 &&
> 1455			    system_state == SYSTEM_RUNNING)
> 1456				schedule_timeout_uninterruptible(2);
> 1457	#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
>
> And it does this while holding the onoff_mutex that bash is waiting for.
>
> Doing a function trace, it showed me where it happened:
>
> [  125.940066] rcu_pree-10      3.... 28384115273: schedule_timeout_uninterruptible <-rcu_gp_kthread
> [...]
> [  125.940066] rcu_pree-10      3d..3 28384202439: sched_switch: prev_comm=rcu_preempt prev_pid=10 prev_prio=120 prev_state=D ==> next_comm=watchdog/3 next_pid=38 next_prio=120
>
> The watchdog ran, and then:
>
> [  125.940066] watchdog-38      3d..3 28384692863: sched_switch: prev_comm=watchdog/3 prev_pid=38 prev_prio=120 prev_state=P ==> next_comm=modprobe next_pid=2848 next_prio=118
>
> Not sure what modprobe was doing, but shortly after that:
>
> [  125.940066] modprobe-2848    3d..3 28385041749: sched_switch: prev_comm=modprobe prev_pid=2848 prev_prio=118 prev_state=R+ ==> next_comm=migration/3 next_pid=40 next_prio=0
>
> Where the migration thread took down the CPU:
>
> [  125.940066] migratio-40      3d..3 28389148276: sched_switch: prev_comm=migration/3 prev_pid=40 prev_prio=0 prev_state=P ==> next_comm=swapper/3 next_pid=0 next_prio=120
>
> which finally did:
>
> [  125.940066]   <idle>-0       3...1 28389282142: arch_cpu_idle_dead <-cpu_startup_entry
> [  125.940066]   <idle>-0       3...1 28389282548: native_play_dead <-arch_cpu_idle_dead
> [  125.940066]   <idle>-0       3...1 28389282924: play_dead_common <-native_play_dead
> [  125.940066]   <idle>-0       3...1 28389283468: idle_task_exit <-play_dead_common
> [  125.940066]   <idle>-0       3...1 28389284644: amd_e400_remove_cpu <-play_dead_common
>
>
> CPU 3 is now offline, the rcu_preempt thread that ran on CPU 3 is still
> doing a schedule_timeout_uninterruptible() and it registered it's
> timeout to the timer base for CPU 3. You would think that it would get
> migrated right? The issue here is that the timer migration happens at
> the CPU notifier for CPU_DEAD. The problem is that the rcu notifier for
> CPU_DOWN is blocked waiting for the onoff_mutex to be released, which is
> held by the thread that just put itself into a uninterruptible sleep,
> that wont wake up until the CPU_DEAD notifier of the timer
> infrastructure is called, which wont happen until the rcu notifier
> finishes. Here's our deadlock!

This commit breaks this deadlock cycle by substituting a shorter udelay()
for the previous schedule_timeout_uninterruptible(), while at the same
time increasing the probability of the delay.  This maintains the intensity
of the testing.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
2013-06-10 13:37:12 -07:00
Steven Rostedt
016a8d5be6 rcu: Don't call wakeup() with rcu_node structure ->lock held
This commit fixes a lockdep-detected deadlock by moving a wake_up()
call out from a rnp->lock critical section.  Please see below for
the long version of this story.

On Tue, 2013-05-28 at 16:13 -0400, Dave Jones wrote:

> [12572.705832] ======================================================
> [12572.750317] [ INFO: possible circular locking dependency detected ]
> [12572.796978] 3.10.0-rc3+ #39 Not tainted
> [12572.833381] -------------------------------------------------------
> [12572.862233] trinity-child17/31341 is trying to acquire lock:
> [12572.870390]  (rcu_node_0){..-.-.}, at: [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12572.878859]
> but task is already holding lock:
> [12572.894894]  (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0
> [12572.903381]
> which lock already depends on the new lock.
>
> [12572.927541]
> the existing dependency chain (in reverse order) is:
> [12572.943736]
> -> #4 (&ctx->lock){-.-...}:
> [12572.960032]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12572.968337]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12572.976633]        [<ffffffff8113c987>] __perf_event_task_sched_out+0x2e7/0x5e0
> [12572.984969]        [<ffffffff81088953>] perf_event_task_sched_out+0x93/0xa0
> [12572.993326]        [<ffffffff816ea0bf>] __schedule+0x2cf/0x9c0
> [12573.001652]        [<ffffffff816eacfe>] schedule_user+0x2e/0x70
> [12573.009998]        [<ffffffff816ecd64>] retint_careful+0x12/0x2e
> [12573.018321]
> -> #3 (&rq->lock){-.-.-.}:
> [12573.034628]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.042930]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.051248]        [<ffffffff8108e6a7>] wake_up_new_task+0xb7/0x260
> [12573.059579]        [<ffffffff810492f5>] do_fork+0x105/0x470
> [12573.067880]        [<ffffffff81049686>] kernel_thread+0x26/0x30
> [12573.076202]        [<ffffffff816cee63>] rest_init+0x23/0x140
> [12573.084508]        [<ffffffff81ed8e1f>] start_kernel+0x3f1/0x3fe
> [12573.092852]        [<ffffffff81ed856f>] x86_64_start_reservations+0x2a/0x2c
> [12573.101233]        [<ffffffff81ed863d>] x86_64_start_kernel+0xcc/0xcf
> [12573.109528]
> -> #2 (&p->pi_lock){-.-.-.}:
> [12573.125675]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.133829]        [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90
> [12573.141964]        [<ffffffff8108e881>] try_to_wake_up+0x31/0x320
> [12573.150065]        [<ffffffff8108ebe2>] default_wake_function+0x12/0x20
> [12573.158151]        [<ffffffff8107bbf8>] autoremove_wake_function+0x18/0x40
> [12573.166195]        [<ffffffff81085398>] __wake_up_common+0x58/0x90
> [12573.174215]        [<ffffffff81086909>] __wake_up+0x39/0x50
> [12573.182146]        [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50
> [12573.190119]        [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0
> [12573.198023]        [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930
> [12573.205860]        [<ffffffff8107a91d>] kthread+0xed/0x100
> [12573.213656]        [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0
> [12573.221379]
> -> #1 (&rsp->gp_wq){..-.-.}:
> [12573.236329]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.243783]        [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90
> [12573.251178]        [<ffffffff810868f3>] __wake_up+0x23/0x50
> [12573.258505]        [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50
> [12573.265891]        [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0
> [12573.273248]        [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930
> [12573.280564]        [<ffffffff8107a91d>] kthread+0xed/0x100
> [12573.287807]        [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0

Notice the above call chain.

rcu_start_future_gp() is called with the rnp->lock held. Then it calls
rcu_start_gp_advance, which does a wakeup.

You can't do wakeups while holding the rnp->lock, as that would mean
that you could not do a rcu_read_unlock() while holding the rq lock, or
any lock that was taken while holding the rq lock. This is because...
(See below).

> [12573.295067]
> -> #0 (rcu_node_0){..-.-.}:
> [12573.309293]        [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0
> [12573.316568]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.323825]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.331081]        [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12573.338377]        [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0
> [12573.345648]        [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0
> [12573.352942]        [<ffffffff8113938e>] find_get_context+0x4e/0x1f0
> [12573.360211]        [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0
> [12573.367514]        [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10
> [12573.374816]        [<ffffffff816f4dd4>] tracesys+0xdd/0xe2

Notice the above trace.

perf took its own ctx->lock, which can be taken while holding the rq
lock. While holding this lock, it did a rcu_read_unlock(). The
perf_lock_task_context() basically looks like:

rcu_read_lock();
raw_spin_lock(ctx->lock);
rcu_read_unlock();

Now, what looks to have happened, is that we scheduled after taking that
first rcu_read_lock() but before taking the spin lock. When we scheduled
back in and took the ctx->lock, the following rcu_read_unlock()
triggered the "special" code.

The rcu_read_unlock_special() takes the rnp->lock, which gives us a
possible deadlock scenario.

	CPU0		CPU1		CPU2
	----		----		----

				     rcu_nocb_kthread()
    lock(rq->lock);
		    lock(ctx->lock);
				     lock(rnp->lock);

				     wake_up();

				     lock(rq->lock);

		    rcu_read_unlock();

		    rcu_read_unlock_special();

		    lock(rnp->lock);
    lock(ctx->lock);

**** DEADLOCK ****

> [12573.382068]
> other info that might help us debug this:
>
> [12573.403229] Chain exists of:
>   rcu_node_0 --> &rq->lock --> &ctx->lock
>
> [12573.424471]  Possible unsafe locking scenario:
>
> [12573.438499]        CPU0                    CPU1
> [12573.445599]        ----                    ----
> [12573.452691]   lock(&ctx->lock);
> [12573.459799]                                lock(&rq->lock);
> [12573.467010]                                lock(&ctx->lock);
> [12573.474192]   lock(rcu_node_0);
> [12573.481262]
>  *** DEADLOCK ***
>
> [12573.501931] 1 lock held by trinity-child17/31341:
> [12573.508990]  #0:  (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0
> [12573.516475]
> stack backtrace:
> [12573.530395] CPU: 1 PID: 31341 Comm: trinity-child17 Not tainted 3.10.0-rc3+ #39
> [12573.545357]  ffffffff825b4f90 ffff880219f1dbc0 ffffffff816e375b ffff880219f1dc00
> [12573.552868]  ffffffff816dfa5d ffff880219f1dc50 ffff88023ce4d1f8 ffff88023ce4ca40
> [12573.560353]  0000000000000001 0000000000000001 ffff88023ce4d1f8 ffff880219f1dcc0
> [12573.567856] Call Trace:
> [12573.575011]  [<ffffffff816e375b>] dump_stack+0x19/0x1b
> [12573.582284]  [<ffffffff816dfa5d>] print_circular_bug+0x200/0x20f
> [12573.589637]  [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0
> [12573.596982]  [<ffffffff810918f5>] ? sched_clock_cpu+0xb5/0x100
> [12573.604344]  [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.611652]  [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0
> [12573.619030]  [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.626331]  [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0
> [12573.633671]  [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12573.640992]  [<ffffffff811390ed>] ? perf_lock_task_context+0x7d/0x2d0
> [12573.648330]  [<ffffffff810b429e>] ? put_lock_stats.isra.29+0xe/0x40
> [12573.655662]  [<ffffffff813095a0>] ? delay_tsc+0x90/0xe0
> [12573.662964]  [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0
> [12573.670276]  [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0
> [12573.677622]  [<ffffffff81139070>] ? __perf_event_enable+0x370/0x370
> [12573.684981]  [<ffffffff8113938e>] find_get_context+0x4e/0x1f0
> [12573.692358]  [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0
> [12573.699753]  [<ffffffff8108cd9d>] ? get_parent_ip+0xd/0x50
> [12573.707135]  [<ffffffff810b71fd>] ? trace_hardirqs_on_caller+0xfd/0x1c0
> [12573.714599]  [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10
> [12573.721996]  [<ffffffff816f4dd4>] tracesys+0xdd/0xe2

This commit delays the wakeup via irq_work(), which is what
perf and ftrace use to perform wakeups in critical sections.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-06-10 13:37:11 -07:00
Paul E. McKenney
d62840995a trace: Allow idle-safe tracepoints to be called from irq
__DECLARE_TRACE_RCU() currently creates an _rcuidle() tracepoint which
may safely be invoked from what RCU considers to be an idle CPU.
However, these _rcuidle() tracepoints may -not- be invoked from the
handler of an irq taken from idle, because rcu_idle_enter() zeroes
RCU's nesting-level counter, so that the rcu_irq_exit() returning to
idle will trigger a WARN_ON_ONCE().

This commit therefore substitutes rcu_irq_enter() for rcu_idle_exit()
and rcu_irq_exit() for rcu_idle_enter() in order to make the _rcuidle()
tracepoints usable from irq handlers as well as from process context.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-06-10 13:37:10 -07:00
David S. Miller
d88210910a Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
The following patchset contains four fixes for Netfilter and one fix
for IPVS, they are:

* Fix data leak to user-space via getsockopt IP_VS_SO_GET_DESTS, from
  Dan Carpenter.

* Fix xt_TCPMSS if no TCP MSS is specified in syn packets, to avoid the
  violation of RFC879, from Phil Oester.

* Fix incomplete dump of objects via nfnetlink_acct and nfnetlink_cttimeout,
  from myself.

* Fix missing HW protocol in packets passed to user-space via NFQUEUE,
  from myself.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-10 13:30:33 -07:00
Linus Torvalds
ab0296319a spi: Fixes for v3.10
A few nasty issues, particularly a race with the interrupt controller in
 the xilinx driver, together with a couple of more minor fixes and a much
 needed move of the mailing list away from sourceforge.
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Merge tag 'spi-v3.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A few nasty issues, particularly a race with the interrupt controller
  in the xilinx driver, together with a couple of more minor fixes and a
  much needed move of the mailing list away from sourceforge."

* tag 'spi-v3.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: hspi: fixup long delay time
  spi: spi-xilinx: Remove ISR race condition
  spi: topcliff-pch: fix error return code in pch_spi_probe()
  spi: topcliff-pch: Pass correct pointer to free_irq()
  spi: Move mailing list to vger
2013-06-10 13:28:39 -07:00
Linus Torvalds
50e6f8511a Bug-fixes for regressions:
- xen/tmem stopped working after a certain combination of modprobe/swapon was used
  - cpu online/offlining would trigger WARN_ON.
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Merge tag 'stable/for-linus-3.10-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen fixes from Konrad Rzeszutek Wilk:
 "Two bug-fixes for regressions:
   - xen/tmem stopped working after a certain combination of
     modprobe/swapon was used
   - cpu online/offlining would trigger WARN_ON."

* tag 'stable/for-linus-3.10-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/tmem: Don't over-write tmem_frontswap_poolid after tmem_frontswap_init set it.
  xen/smp: Fixup NOHZ per cpu data when onlining an offline CPU.
2013-06-10 13:27:46 -07:00
Linus Torvalds
30f5f73926 regmap: Fixes for v3.10
The biggest fix here is Lars-Peter's fix for custom locking callbacks
 which is pretty localised but important for those devices that use the
 feature.  Otherwise we've got a couple of fairly small cleanups which
 would have been sent sooner were it not for letting Lars-Peter's patch
 soak for a while.
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Merge tag 'regmap-v3.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fixes from Mark Brown:
 "The biggest fix here is Lars-Peter's fix for custom locking callbacks
  which is pretty localised but important for those devices that use the
  feature.  Otherwise we've got a couple of fairly small cleanups which
  would have been sent sooner were it not for letting Lars-Peter's patch
  soak for a while"

* tag 'regmap-v3.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: rbtree: Fixed node range check on sync
  regmap: regcache: Fixup locking for custom lock callbacks
  regmap: debugfs: Check return value of regmap_write()
2013-06-10 13:26:41 -07:00
Linus Torvalds
822b4b6fe3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes a build problem in sahara and temporarily disables two new
  optimisations because of performance regressions until a permanent fix
  is ready"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: sahara - fix building as module
  crypto: blowfish - disable AVX2 implementation
  crypto: twofish - disable AVX2 implementation
2013-06-10 13:25:50 -07:00
Gabor Juhos
10af87c3d9 rt2x00: rt2x00queue: initialize data_queue fields earlier
Support for rt2800 device is broken since my
'rt2x00: rt2x00dev: use rt2x00dev->tx->limit'
patch. The changelog of that commit says that the
TX data queue is initialized already when the
rt2x00lib_probe_hw() function is called.

However as Jakub noticed it, this statement is not
correct. The queue->limit field is initialized in
the rt2x00queue_alloc_entries routine and that is
not yet called when rt2x00lib_probe_hw() runs.
Because the value of tx->limit contains zero, the
driver tries to allocate a kernel fifo with zero
size and kfifo_alloc rejects that with -EINVAL.

  PCI: Enabling device 0000:01:00.0 (0000 -> 0002)
  ieee80211 phy1: rt2x00_set_rt: Info - RT chipset 3071, rev 021c detected
  ieee80211 phy1: rt2x00_set_rf: Info - RF chipset 0008 detected
  ieee80211 phy1: rt2x00lib_probe_dev: Error - Failed to initialize hw
  rt2800pci: probe of 0000:01:00.0 failed with error -22

Move the data_queue field initialization from
the rt2x00queue_alloc_entries routine into the
rt2x00queue_init function. The initialization
code is not strictly related to the allocation,
and the change ensures that the queue_data fields
can be used in the probe routines.

The patch also introduces a helper function in
order to be able to get the correct data_queue_desc
structure for a given queue. This helper is only
needed temporarily and it will be removed later.

Reported-by: Jakub Kicinski <moorray@wp.pl>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-06-10 15:37:34 -04:00
Yunlian Jiang
ec71997eff rtlwifi: initialize local array and set value.
GCC 4.8 is spitting out uninitialized-variable warnings against
"drivers/net/wireless/rtlwifi/rtl8192de/dm.c".

drivers/net/wireless/rtlwifi/rtl8192de/dm.c:941:31:
error: 'ofdm_index_old[1]' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
     rtlpriv->dm.ofdm_index[i] = ofdm_index_old[i];

This patch adds initialization to the variable and properly sets its value.

Signed-off-by: Yunlian Jiang <yunlian@google.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-06-10 15:37:34 -04:00
John W. Linville
76015021aa Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-next 2013-06-10 14:51:17 -04:00
Dan Carpenter
f7a01cac73 cw1200: handle allocation failure in wsm_event_indication()
Check for allocation failures and return -ENOMEM.  The caller
already expects it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-06-10 14:41:26 -04:00
Dan Carpenter
f28bc92c95 cw1200: read beyond end of array in debug code
This has only one caller and rates[] is an array with
IEEE80211_TX_MAX_RATES (4) elements.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-06-10 14:41:26 -04:00