linux-toradex.git/kernel, branch v3.18.18

tracing/filter: Do not allow infix to exceed end of string

2015-07-05T14:12:52+00:00

[ Upstream commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 ]

While debugging a WARN_ON() for filtering, I found that it is possible
for the filter string to be referenced after its end. With the filter:

 # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter

The filter_parse() function can call infix_get_op() which calls
infix_advance() that updates the infix filter pointers for the cnt
and tail without checking if the filter is already at the end, which
will put the cnt to zero and the tail beyond the end. The loop then calls
infix_next() that has

	ps->infix.cnt--;
	return ps->infix.string[ps->infix.tail++];

The cnt will now be below zero, and the tail that is returned is
already passed the end of the filter string. So far the allocation
of the filter string usually has some buffer that is zeroed out, but
if the filter string is of the exact size of the allocated buffer
there's no guarantee that the charater after the nul terminating
character will be zero.

Luckily, only root can write to the filter.

Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Steven Rostedt 
Signed-off-by: Sasha Levin

PM / sleep: Increase default DPM watchdog timeout to 60

2015-07-05T14:12:49+00:00

[ Upstream commit fff3b16d2754a061a3549c4307a186423a0128fd ]

Many harddisks (mostly WD ones) have firmware problems and take too
long, more than 10 seconds, to resume from suspend.  And this often
exceeds the default DPM watchdog timeout (12 seconds), resulting in a
kernel panic out of sudden.

Since most distros just take the default as is, we should give a bit
more safer value.  This patch increases the default value from 12
seconds to one minute, which has been confirmed to be long enough for
such problematic disks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=91921
Fixes: 70fea60d888d (PM / Sleep: Detect device suspend/resume lockup and log event)
Cc: 3.13+  # 3.13+
Signed-off-by: Takashi Iwai 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

rcu: Correctly handle non-empty Tiny RCU callback list with none ready

2015-07-04T03:02:21+00:00

[ Upstream commit 6e91f8cb138625be96070b778d9ba71ce520ea7e ]

If, at the time __rcu_process_callbacks() is invoked,  there are callbacks
in Tiny RCU's callback list, but none of them are ready to be invoked,
the current list-management code will knit the non-ready callbacks out
of the list.  This can result in hangs and possibly worse.  This commit
therefore inserts a check for there being no callbacks that can be
invoked immediately.

This bug is unlikely to occur -- you have to get a new callback between
the time rcu_sched_qs() or rcu_bh_qs() was called, but before we get to
__rcu_process_callbacks().  It was detected by the addition of RCU-bh
testing to rcutorture, which in turn was instigated by Iftekhar Ahmed's
mutation testing.  Although this bug was made much more likely by
915e8a4fe45e (rcu: Remove fastpath from __rcu_process_callbacks()), this
did not cause the bug, but rather made it much more probable.   That
said, it takes more than 40 hours of rcutorture testing, on average,
for this bug to appear, so this fix cannot be considered an emergency.

Signed-off-by: Paul E. McKenney 
Cc: 
Reviewed-by: Josh Triplett 
Signed-off-by: Sasha Levin

genirq: devres: Fix testing return value of request_any_context_irq()

2015-07-04T03:02:16+00:00

[ Upstream commit 63781394c540dd9e666a6b21d70b64dd52bce76e ]

request_any_context_irq() returns a negative value on failure.
It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success.
So fix testing return value of request_any_context_irq().

Also fixup the return value of devm_request_any_context_irq() to make it
consistent with request_any_context_irq().

Fixes: 0668d3065128 ("genirq: Add devm_request_any_context_irq()")
Signed-off-by: Axel Lin 
Reviewed-by: Stephen Boyd 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Sasha Levin

ring-buffer-benchmark: Fix the wrong sched_priority of producer

2015-07-03T16:34:40+00:00

[ Upstream commit 108029323910c5dd1ef8fa2d10da1ce5fbce6e12 ]

The producer should be used producer_fifo as its sched_priority,
so correct it.

Link: http://lkml.kernel.org/r/1433923957-67842-1-git-send-email-long.wanglong@huawei.com

Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Wang Long 
Signed-off-by: Steven Rostedt 
Signed-off-by: Sasha Levin

ksoftirqd: Enable IRQs and call cond_resched() before poking RCU

2015-07-03T16:34:28+00:00

[ Upstream commit 28423ad283d5348793b0c45cc9b1af058e776fd6 ]

While debugging an issue with excessive softirq usage, I encountered the
following note in commit 3e339b5dae24a706 ("softirq: Use hotplug thread
infrastructure"):

    [ paulmck: Call rcu_note_context_switch() with interrupts enabled. ]

...but despite this note, the patch still calls RCU with IRQs disabled.

This seemingly innocuous change caused a significant regression in softirq
CPU usage on the sending side of a large TCP transfer (~1 GB/s): when
introducing 0.01% packet loss, the softirq usage would jump to around 25%,
spiking as high as 50%. Before the change, the usage would never exceed 5%.

Moving the call to rcu_note_context_switch() after the cond_sched() call,
as it was originally before the hotplug patch, completely eliminated this
problem.

Signed-off-by: Calvin Owens 
Cc: stable@vger.kernel.org
Signed-off-by: Paul E. McKenney 
Signed-off-by: Sasha Levin

sched, numa: Do not hint for NUMA balancing on VM_MIXEDMAP mappings

2015-06-22T04:11:41+00:00

commit 8e76d4eecf7afeec9328e21cd5880e281838d0d6 upstream.

Jovi Zhangwei reported the following problem

  Below kernel vm bug can be triggered by tcpdump which mmaped a lot of pages
  with GFP_COMP flag.

  [Mon May 25 05:29:33 2015] page:ffffea0015414000 count:66 mapcount:1 mapping:          (null) index:0x0
  [Mon May 25 05:29:33 2015] flags: 0x20047580004000(head)
  [Mon May 25 05:29:33 2015] page dumped because: VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page))
  [Mon May 25 05:29:33 2015] ------------[ cut here ]------------
  [Mon May 25 05:29:33 2015] kernel BUG at mm/migrate.c:1661!
  [Mon May 25 05:29:33 2015] invalid opcode: 0000 [#1] SMP

In this case it was triggered by running tcpdump but it's not necessary
reproducible on all systems.

  sudo tcpdump -i bond0.100 'tcp port 4242' -c 100000000000 -w 4242.pcap

Compound pages cannot be migrated and it was not expected that such pages
be marked for NUMA balancing.  This did not take into account that drivers
such as net/packet/af_packet.c may insert compound pages into userspace
with vm_insert_page.  This patch tells the NUMA balancing protection
scanner to skip all VM_MIXEDMAP mappings which avoids the possibility that
compound pages are marked for migration.

Signed-off-by: Mel Gorman 
Reported-by: Jovi Zhangwei 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[jovi: Backported to 3.18: adjust context]
Signed-off-by: Jovi Zhangwei 
Signed-off-by: Sasha Levin

sched: Handle priority boosted tasks proper in setscheduler()

2015-06-10T17:42:31+00:00

[ Upstream commit 0782e63bc6fe7e2d3408d250df11d388b7799c6b ]

Ronny reported that the following scenario is not handled correctly:

	T1 (prio = 10)
	   lock(rtmutex);

	T2 (prio = 20)
	   lock(rtmutex)
	      boost T1

	T1 (prio = 20)
	   sys_set_scheduler(prio = 30)
	   T1 prio = 30
	   ....
	   sys_set_scheduler(prio = 10)
	   T1 prio = 30

The last step is wrong as T1 should now be back at prio 20.

Commit c365c292d059 ("sched: Consider pi boosting in setscheduler()")
only handles the case where a boosted tasks tries to lower its
priority.

Fix it by taking the new effective priority into account for the
decision whether a change of the priority is required.

Reported-by: Ronny Meeus 
Tested-by: Steven Rostedt 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Steven Rostedt 
Cc: 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Mike Galbraith 
Fixes: c365c292d059 ("sched: Consider pi boosting in setscheduler()")
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanos
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

module: Call module notifier on failure after complete_formation()

2015-06-09T18:31:44+00:00

[ Upstream commit 37815bf866ab6722a47550f8d25ad3f1a16a680c ]

The module notifier call chain for MODULE_STATE_COMING was moved up before
the parsing of args, into the complete_formation() call. But if the module failed
to load after that, the notifier call chain for MODULE_STATE_GOING was
never called and that prevented the users of those call chains from
cleaning up anything that was allocated.

Link: http://lkml.kernel.org/r/554C52B9.9060700@gmail.com

Reported-by: Pontus Fuchs 
Fixes: 4982223e51e8 "module: set nx before marking module MODULE_STATE_COMING"
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Steven Rostedt 
Signed-off-by: Rusty Russell 
Signed-off-by: Sasha Levin

ktime: Fix ktime_divns to do signed division

2015-06-09T17:43:50+00:00

[ Upstream commit f7bcb70ebae0dcdb5a2d859b09e4465784d99029 ]

It was noted that the 32bit implementation of ktime_divns()
was doing unsigned division and didn't properly handle
negative values.

And when a ktime helper was changed to utilize
ktime_divns, it caused a regression on some IR blasters.
See the following bugzilla for details:
  https://bugzilla.redhat.com/show_bug.cgi?id=1200353

This patch fixes the problem in ktime_divns by checking
and preserving the sign bit, and then reapplying it if
appropriate after the division, it also changes the return
type to a s64 to make it more obvious this is expected.

Nicolas also pointed out that negative dividers would
cause infinite loops on 32bit systems, negative dividers
is unlikely for users of this function, but out of caution
this patch adds checks for negative dividers for both
32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure
no such use cases creep in.

[ tglx: Hand an u64 to do_div() to avoid the compiler warning ]

Fixes: 166afb64511e 'ktime: Sanitize ktime_to_us/ms conversion'
Reported-and-tested-by: Trevor Cordes 
Signed-off-by: John Stultz 
Acked-by: Nicolas Pitre 
Cc: Ingo Molnar 
Cc: Josh Boyer 
Cc: One Thousand Gnomes 
Cc: 
Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner 
Signed-off-by: Sasha Levin