linux-toradex.git/include/linux, branch v3.14.7

percpu-refcount: fix usage of this_cpu_ops

2014-06-11T18:54:13+00:00

commit 0c36b390a546055b6815d4b93a2c9fed4d980ffb upstream.

The percpu-refcount infrastructure uses the underscore variants of
this_cpu_ops in order to modify percpu reference counters.
(e.g. __this_cpu_inc()).

However the underscore variants do not atomically update the percpu
variable, instead they may be implemented using read-modify-write
semantics (more than one instruction).  Therefore it is only safe to
use the underscore variant if the context is always the same (process,
softirq, or hardirq). Otherwise it is possible to lose updates.

This problem is something that Sebastian has seen within the aio
subsystem which uses percpu refcounters both in process and softirq
context leading to reference counts that never dropped to zeroes; even
though the number of "get" and "put" calls matched.

Fix this by using the non-underscore this_cpu_ops variant which
provides correct per cpu atomic semantics and fixes the corrupted
reference counts.

Cc: Kent Overstreet 
Reported-by: Sebastian Ott 
Signed-off-by: Heiko Carstens 
Signed-off-by: Tejun Heo 
References: http://lkml.kernel.org/g/alpine.LFD.2.11.1406041540520.21183@denkbrett
Signed-off-by: Greg Kroah-Hartman

dmaengine: fix dmaengine_unmap failure

2014-06-07T17:28:25+00:00

commit c1f43dd9c20d85e66c4d77e284f64ac114abe3f8 upstream.

The count which is used to get_unmap_data maybe not the same as the
count computed in dmaengine_unmap which causes to free data in a
wrong pool.

This patch fixes this issue by keeping the map count with unmap_data
structure and use this count to get the pool.

Signed-off-by: Xuelin Shi 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

genirq: Provide irq_force_affinity fallback for non-SMP

2014-06-07T17:28:24+00:00

commit 4c88d7f9b0d5fb0588c3386be62115cc2eaa8f9f upstream.

Patch 01f8fa4f01d "genirq: Allow forcing cpu affinity of interrupts" added
an irq_force_affinity() function, and 30ccf03b4a6 "clocksource: Exynos_mct:
Use irq_force_affinity() in cpu bringup" subsequently uses it. However, the
driver can be used with CONFIG_SMP disabled, but the function declaration
is only available for CONFIG_SMP, leading to this build error:

drivers/clocksource/exynos_mct.c:431:3: error: implicit declaration of function 'irq_force_affinity' [-Werror=implicit-function-declaration]
   irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));

This patch introduces a dummy helper function for the non-SMP case
that always returns success, to get rid of the build error.
Since the patches causing the problem are marked for stable backports,
this one should be as well.

Signed-off-by: Arnd Bergmann 
Cc: Krzysztof Kozlowski 
Acked-by: Kukjin Kim 
Link: http://lkml.kernel.org/r/5619084.0zmrrIUZLV@wuerfel
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Input: serio - add firmware_id sysfs attribute

2014-06-07T17:28:19+00:00

commit 0456c66f4e905e1ca839318219c770988b47975c upstream.

serio devices exposed via platform firmware interfaces such as ACPI may
provide additional identifying information of use to userspace.

We don't associate the serio devices with the firmware device (we don't
set it as parent), so there's no way for userspace to make use of this
information.

We cannot change the parent for serio devices instantiated though a
firmware interface as that would break suspend / resume ordering.

Therefore this patch adds a new firmware_id sysfs attribute so that
userspace can get a string from there with any additional identifying
information the firmware interface may provide.

Signed-off-by: Hans de Goede 
Acked-by: Peter Hutterer 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Greg Kroah-Hartman

genirq: Allow forcing cpu affinity of interrupts

2014-06-07T17:28:08+00:00

commit 01f8fa4f01d8362358eb90e412bd7ae18a3ec1ad upstream.

The current implementation of irq_set_affinity() refuses rightfully to
route an interrupt to an offline cpu.

But there is a special case, where this is actually desired. Some of
the ARM SoCs have per cpu timers which require setting the affinity
during cpu startup where the cpu is not yet in the online mask.

If we can't do that, then the local timer interrupt for the about to
become online cpu is routed to some random online cpu.

The developers of the affected machines tried to work around that
issue, but that results in a massive mess in that timer code.

We have a yet unused argument in the set_affinity callbacks of the irq
chips, which I added back then for a similar reason. It was never
required so it got not used. But I'm happy that I never removed it.

That allows us to implement a sane handling of the above scenario. So
the affected SoC drivers can add the required force handling to their
interrupt chip, switch the timer code to irq_force_affinity() and
things just work.

This does not affect any existing user of irq_set_affinity().

Tagged for stable to allow a simple fix of the affected SoC clock
event drivers.

Reported-and-tested-by: Krzysztof Kozlowski 
Signed-off-by: Thomas Gleixner 
Cc: Kyungmin Park 
Cc: Marek Szyprowski 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Tomasz Figa ,
Cc: Daniel Lezcano ,
Cc: Kukjin Kim 
Cc: linux-arm-kernel@lists.infradead.org,
Link: http://lkml.kernel.org/r/20140416143315.717251504@linutronix.de
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

of/irq: do irq resolution in platform_get_irq

2014-06-07T17:28:07+00:00

commit 9ec36cafe43bf835f8f29273597a5b0cbc8267ef upstream.

Currently we get the following kind of errors if we try to use interrupt
phandles to irqchips that have not yet initialized:

irq: no irq domain found for /ocp/pinmux@48002030 !
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184()
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012
(show_stack+0x14/0x1c)
(dump_stack+0x6c/0xa0)
(warn_slowpath_common+0x64/0x84)
(warn_slowpath_null+0x1c/0x24)
(of_device_alloc+0x144/0x184)
(of_platform_device_create_pdata+0x44/0x9c)
(of_platform_bus_create+0xd0/0x170)
(of_platform_bus_create+0x12c/0x170)
(of_platform_populate+0x60/0x98)

This is because we're wrongly trying to populate resources that are not
yet available. It's perfectly valid to create irqchips dynamically, so
let's fix up the issue by resolving the interrupt resources when
platform_get_irq is called.

And then we also need to accept the fact that some irqdomains do not
exist that early on, and only get initialized later on. So we can
make the current WARN_ON into just into a pr_debug().

We still attempt to populate irq resources when we create the devices.
This allows current drivers which don't use platform_get_irq to continue
to function. Once all drivers are fixed, this code can be removed.

Suggested-by: Russell King 
Signed-off-by: Rob Herring 
Signed-off-by: Tony Lindgren 
Tested-by: Tony Lindgren 
Signed-off-by: Grant Likely 
Signed-off-by: Greg Kroah-Hartman

ftrace/module: Hardcode ftrace_module_init() call into load_module()

2014-06-07T17:28:07+00:00

commit a949ae560a511fe4e3adf48fa44fefded93e5c2b upstream.

A race exists between module loading and enabling of function tracer.

	CPU 1				CPU 2
	-----				-----
  load_module()
   module->state = MODULE_STATE_COMING

				register_ftrace_function()
				 mutex_lock(&ftrace_lock);
				 ftrace_startup()
				  update_ftrace_function();
				   ftrace_arch_code_modify_prepare()
				    set_all_module_text_rw();
				   
				    ftrace_arch_code_modify_post_process()
				     set_all_module_text_ro();

				[ here all module text is set to RO,
				  including the module that is
				  loading!! ]

   blocking_notifier_call_chain(MODULE_STATE_COMING);
    ftrace_init_module()

     [ tries to modify code, but it's RO, and fails!
       ftrace_bug() is called]

When this race happens, ftrace_bug() will produces a nasty warning and
all of the function tracing features will be disabled until reboot.

The simple solution is to treate module load the same way the core
kernel is treated at boot. To hardcode the ftrace function modification
of converting calls to mcount into nops. This is done in init/main.c
there's no reason it could not be done in load_module(). This gives
a better control of the changes and doesn't tie the state of the
module to its notifiers as much. Ftrace is special, it needs to be
treated as such.

The reason this would work, is that the ftrace_module_init() would be
called while the module is in MODULE_STATE_UNFORMED, which is ignored
by the set_all_module_text_ro() call.

Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com

Reported-by: Takao Indoh 
Acked-by: Rusty Russell 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

rtnetlink: wait for unregistering devices in rtnl_link_unregister()

2014-05-31T20:20:38+00:00

[ Upstream commit 200b916f3575bdf11609cb447661b8d5957b0bbf ]

From: Cong Wang 

commit 50624c934db18ab90 (net: Delay default_device_exit_batch until no
devices are unregistering) introduced rtnl_lock_unregistering() for
default_device_exit_batch(). Same race could happen we when rmmod a driver
which calls rtnl_link_unregister() as we call dev->destructor without rtnl
lock.

For long term, I think we should clean up the mess of netdev_run_todo()
and net namespce exit code.

Cc: Eric W. Biederman 
Cc: David S. Miller 
Signed-off-by: Cong Wang 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: avoid dependency of net_get_random_once on nop patching

2014-05-31T20:20:38+00:00

[ Upstream commit 3d4405226d27b3a215e4d03cfa51f536244e5de7 ]

net_get_random_once depends on the static keys infrastructure to patch up
the branch to the slow path during boot. This was realized by abusing the
static keys api and defining a new initializer to not enable the call
site while still indicating that the branch point should get patched
up. This was needed to have the fast path considered likely by gcc.

The static key initialization during boot up normally walks through all
the registered keys and either patches in ideal nops or enables the jump
site but omitted that step on x86 if ideal nops where already placed at
static_key branch points. Thus net_get_random_once branches not always
became active.

This patch switches net_get_random_once to the ordinary static_key
api and thus places the kernel fast path in the - by gcc considered -
unlikely path.  Microbenchmarks on Intel and AMD x86-64 showed that
the unlikely path actually beats the likely path in terms of cycle cost
and that different nop patterns did not make much difference, thus this
switch should not be noticeable.

Fixes: a48e42920ff38b ("net: introduce new macro net_get_random_once")
Reported-by: Tuomas Räsänen 
Cc: Linus Torvalds 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Fix ns_capable check in sock_diag_put_filterinfo

2014-05-31T20:20:34+00:00

[ Upstream commit 78541c1dc60b65ecfce5a6a096fc260219d6784e ]

The caller needs capabilities on the namespace being queried, not on
their own namespace.  This is a security bug, although it likely has
only a minor impact.

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman