linux-toradex.git/kernel, branch v2.6.37.2

perf: Fix throttle logic

2011-02-24T22:54:40+00:00

commit 4fe757dd48a9e95e1a071291f15dda5421dacb66 upstream.

It was possible to call pmu::start() on an already running event. In
particular this lead so some wreckage as the hrtimer events would
re-initialize active timers.

This was due to throttled events being activated again by scheduling.
Scheduling in a context would add and force start events, resulting in
running events with a possible throttle status. The next tick to hit
that task will then try to unthrottle the event and call ->start() on
an already running event.

Reported-by: Jeff Moyer 
Signed-off-by: Peter Zijlstra 
LKML-Reference: 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now

2011-02-24T22:54:40+00:00

commit 6d83f94db95cfe65d2a6359cccdf61cf087c2598 upstream.

With CONFIG_SHIRQ_DEBUG=y we call a newly installed interrupt handler
in request_threaded_irq().

The original implementation (commit a304e1b8) called the handler
_BEFORE_ it was installed, but that caused problems with handlers
calling disable_irq_nosync(). See commit 377bf1e4.

It's braindead in the first place to call disable_irq_nosync in shared
handlers, but ....

Moving this call after we installed the handler looks innocent, but it
is very subtle broken on SMP.

Interrupt handlers rely on the fact, that the irq core prevents
reentrancy.

Now this debug call violates that promise because we run the handler
w/o the IRQ_INPROGRESS protection - which we cannot apply here because
that would result in a possibly forever masked interrupt line.

A concurrent real hardware interrupt on a different CPU results in
handler reentrancy and can lead to complete wreckage, which was
unfortunately observed in reality and took a fricking long time to
debug.

Leave the code here for now. We want this debug feature, but that's
not easy to fix. We really should get rid of those
disable_irq_nosync() abusers and remove that function completely.

Signed-off-by: Thomas Gleixner 
Cc: Anton Vorontsov 
Cc: David Woodhouse 
Cc: Arjan van de Ven 
Signed-off-by: Greg Kroah-Hartman

genirq: Prevent access beyond allocated_irqs bitmap

2011-02-24T22:54:40+00:00

commit c1ee6264280e740a9d3ff3feef38642cf0a57013 upstream.

Lars-Peter Clausen pointed out:

   I stumbled upon this while looking through the existing archs using
   SPARSE_IRQ.  Even with SPARSE_IRQ the NR_IRQS is still the upper
   limit for the number of IRQs.

   Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
   IRQ_BOARD_START being the number of IRQs used by the core.

   In various machine files the nr_irqs field of the ARM machine
   defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".

   As a result "nr_irqs" will greater then NR_IRQS which then again
   causes the "allocated_irqs" bitmap in the core irq code to be
   accessed beyond its size overwriting unrelated data.

The core code really misses a sanity check there.

This went unnoticed so far as by chance the compiler/linker places
data behind that bitmap which gets initialized later on those affected
platforms.

So the obvious fix would be to add a sanity check in early_irq_init()
and break all affected platforms. Though that check wants to be
backported to stable as well, which will require to fix all known
problematic platforms and probably some more yet not known ones as
well. Lots of churn.

A way simpler solution is to allocate a slightly larger bitmap and
avoid the whole churn w/o breaking anything. Add a few warnings when
an arch returns utter crap.

Reported-by: Lars-Peter Clausen 
Signed-off-by: Thomas Gleixner 
Cc: Haojian Zhuang 
Cc: Eric Miao 
Cc: Peter Zijlstra 
Signed-off-by: Greg Kroah-Hartman

workqueue: make sure MAYDAY_INITIAL_TIMEOUT is at least 2 jiffies long

2011-02-24T22:54:32+00:00

commit 3233cdbd9fa347a6d6897a94cc6ed0302ae83c4f upstream.

MAYDAY_INITIAL_TIMEOUT is defined as HZ / 100 and depending on
configuration may end up 0 or 1.  Even when it's 1, depending on when
the mayday timer is added in the current jiffy interval, it may expire
way before a jiffy has passed.

Make sure MAYDAY_INITIAL_TIMEOUT is at least two to guarantee that at
least a full jiffy has passed before calling rescuers.

Signed-off-by: Tejun Heo 
Reported-by: Ray Jui 
Signed-off-by: Greg Kroah-Hartman

workqueue: wake up a worker when a rescuer is leaving a gcwq

2011-02-24T22:54:32+00:00

commit 7576958a9d5a4a677ad7dd40901cdbb6c1110c98 upstream.

After executing the matching works, a rescuer leaves the gcwq whether
there are more pending works or not.  This may decrease the
concurrency level to zero and stall execution until a new work item is
queued on the gcwq.

Make rescuer wake up a regular worker when it leaves a gcwq if there
are more works to execute, so that execution isn't stalled.

Signed-off-by: Tejun Heo 
Reported-by: Ray Jui 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Return error code when alloc_image_page() fails

2011-02-24T22:54:31+00:00

commit 2e725a065b0153f0c449318da1923a120477633d upstream.

Currently we return 0 in swsusp_alloc() when alloc_image_page() fails.
Fix that.  Also remove unneeded "error" variable since the only
useful value of error is -ENOMEM.

[rjw: Fixed up the changelog and changed subject.]

Signed-off-by: Stanislaw Gruszka 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

security: add cred argument to security_capable()

2011-02-24T22:54:29+00:00

commit 6037b715d6fab139742c3df8851db4c823081561 upstream.

Expand security_capable() to include cred, so that it can be usable in a
wider range of call sites.

Signed-off-by: Chris Wright 
Acked-by: Serge Hallyn 
Signed-off-by: James Morris 
Signed-off-by: Greg Kroah-Hartman

CRED: Fix memory and refcount leaks upon security_prepare_creds() failure

2011-02-24T22:54:28+00:00

commit fb2b2a1d37f80cc818fd4487b510f4e11816e5e1 upstream.

In prepare_kernel_cred() since 2.6.29, put_cred(new) is called without
assigning new->usage when security_prepare_creds() returned an error.  As a
result, memory for new and refcount for new->{user,group_info,tgcred} are
leaked because put_cred(new) won't call __put_cred() unless old->usage == 1.

Fix these leaks by assigning new->usage (and new->subscribers which was added
in 2.6.32) before calling security_prepare_creds().

Signed-off-by: Tetsuo Handa 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

CRED: Fix BUG() upon security_cred_alloc_blank() failure

2011-02-24T22:54:28+00:00

commit 2edeaa34a6e3f2c43b667f6c4f7b27944b811695 upstream.

In cred_alloc_blank() since 2.6.32, abort_creds(new) is called with
new->security == NULL and new->magic == 0 when security_cred_alloc_blank()
returns an error.  As a result, BUG() will be triggered if SELinux is enabled
or CONFIG_DEBUG_CREDENTIALS=y.

If CONFIG_DEBUG_CREDENTIALS=y, BUG() is called from __invalid_creds() because
cred->magic == 0.  Failing that, BUG() is called from selinux_cred_free()
because selinux_cred_free() is not expecting cred->security == NULL.  This does
not affect smack_cred_free(), tomoyo_cred_free() or apparmor_cred_free().

Fix these bugs by

(1) Set new->magic before calling security_cred_alloc_blank().

(2) Handle null cred->security in creds_are_invalid() and selinux_cred_free().

Signed-off-by: Tetsuo Handa 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent

2011-02-17T23:15:07+00:00

commit 8c6a98b22b750c9eb52653ba643faa17db8d3881 upstream.

Currently sysrq_enabled and __sysrq_enabled are initialised separately
and inconsistently, leading to sysrq being actually enabled by reported
as not enabled in sysfs.  The first change to the sysfs configurable
synchronises these two:

    static int __read_mostly sysrq_enabled = 1;
    static int __sysrq_enabled;

Add a common define to carry the default for these preventing them becoming
out of sync again.  Default this to 1 to mirror previous behaviour.

Signed-off-by: Andy Whitcroft 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Greg Kroah-Hartman