linux/kernel, branch v2.6.32.55

kprobes: initialize before using a hlist

2012-01-25T21:53:25Z

commit d496aab567e7e52b3e974c9192a5de6e77dce32c upstream. Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed locking") introduced a bug where we can potentially leak kretprobe_instances since we initialize a hlist head after having used it. Initialize the hlist head before using it. Reported by: Jim Keniston Acked-by: Jim Keniston Signed-off-by: Ananth N Mavinakayanahalli Acked-by: Masami Hiramatsu Cc: Srinivasa D S Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

PM / Sleep: Fix race between CPU hotplug and freezer

2012-01-12T19:40:11Z

commit 79cfbdfa87e84992d509e6c1648a18e1d7e68c20 upstream. The CPU hotplug notifications sent out by the _cpu_up() and _cpu_down() functions depend on the value of the 'tasks_frozen' argument passed to them (which indicates whether tasks have been frozen or not). (Examples for such CPU hotplug notifications: CPU_ONLINE, CPU_ONLINE_FROZEN, CPU_DEAD, CPU_DEAD_FROZEN). Thus, it is essential that while the callbacks for those notifications are running, the state of the system with respect to the tasks being frozen or not remains unchanged, *throughout that duration*. Hence there is a need for synchronizing the CPU hotplug code with the freezer subsystem. Since the freezer is involved only in the Suspend/Hibernate call paths, this patch hooks the CPU hotplug code to the suspend/hibernate notifiers PM_[SUSPEND|HIBERNATE]_PREPARE and PM_POST_[SUSPEND|HIBERNATE] to prevent the race between CPU hotplug and freezer, thus ensuring that CPU hotplug notifications will always be run with the state of the system really being what the notifications indicate, _throughout_ their execution time. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

hung_task: fix false positive during vfork

2012-01-06T23:38:03Z

commit f9fab10bbd768b0e5254e53a4a8477a94bfc4b96 upstream. vfork parent uninterruptibly and unkillably waits for its child to exec/exit. This wait is of unbounded length. Ignore such waits in the hung_task detector. Signed-off-by: Mandeep Singh Baines Reported-by: Sasha Levin LKML-Reference: <1325344394.28904.43.camel@lappy> Cc: Linus Torvalds Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Andrew Morton Cc: John Kacur Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Revert "clockevents: Set noop handler in clockevents_exchange_device()"

2012-01-03T17:49:22Z

commit 3b87487ac5008072f138953b07505a7e3493327f upstream. This reverts commit de28f25e8244c7353abed8de0c7792f5f883588c. It results in resume problems for various people. See for example http://thread.gmane.org/gmane.linux.kernel/1233033 http://thread.gmane.org/gmane.linux.kernel/1233389 http://thread.gmane.org/gmane.linux.kernel/1233159 http://thread.gmane.org/gmane.linux.kernel/1227868/focus=1230877 and the fedora and ubuntu bug reports https://bugzilla.redhat.com/show_bug.cgi?id=767248 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/904569 which got bisected down to the stable version of this commit. Reported-by: Jonathan Nieder Reported-by: Phil Miller Reported-by: Philip Langdale Reported-by: Tim Gardner Cc: Thomas Gleixner Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Make TASKSTATS require root access

2011-12-21T21:04:53Z

commit 1a51410abe7d0ee4b1d112780f46df87d3621043 upstream. Ok, this isn't optimal, since it means that 'iotop' needs admin capabilities, and we may have to work on this some more. But at the same time it is very much not acceptable to let anybody just read anybody elses IO statistics quite at this level. Use of the GENL_ADMIN_PERM suggested by Johannes Berg as an alternative to checking the capabilities by hand. Reported-by: Vasiliy Kulikov Cc: Johannes Berg Acked-by: Balbir Singh Signed-off-by: Linus Torvalds Cc: Moritz Mühlenhoff Signed-off-by: Greg Kroah-Hartman

clockevents: Set noop handler in clockevents_exchange_device()

2011-12-09T17:21:52Z

commit de28f25e8244c7353abed8de0c7792f5f883588c upstream. If a device is shutdown, then there might be a pending interrupt, which will be processed after we reenable interrupts, which causes the original handler to be run. If the old handler is the (broadcast) periodic handler the shutdown state might hang the kernel completely. Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tick-broadcast: Stop active broadcast device when replacing it

2011-12-09T17:21:51Z

commit c1be84309c58b1e7c6d626e28fba41a22b364c3d upstream. When a better rated broadcast device is installed, then the current active device is not disabled, which results in two running broadcast devices. Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

genirq: Fix race condition when stopping the irq thread

2011-12-09T17:21:50Z

commit 550acb19269d65f32e9ac4ddb26c2b2070e37f1c upstream. In irq_wait_for_interrupt(), the should_stop member is verified before setting the task's state to TASK_INTERRUPTIBLE and calling schedule(). In case kthread_stop sets should_stop and wakes up the process after should_stop is checked by the irq thread but before the task's state is changed, the irq thread might never exit: kthread_stop irq_wait_for_interrupt ------------ ---------------------- ... ... while (!kthread_should_stop()) { kthread->should_stop = 1; wake_up_process(k); wait_for_completion(&kthread->exited); ... set_current_state(TASK_INTERRUPTIBLE); ... schedule(); } Fix this by checking if the thread should stop after modifying the task's state. [ tglx: Simplified it a bit ] Signed-off-by: Ido Yariv Link: http://lkml.kernel.org/r/1322740508-22640-1-git-send-email-ido@wizery.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

timekeeping: add arch_offset hook to ktime_get functions

2011-12-09T17:21:38Z

commit d004e024058a0eaca097513ce62cbcf978913e0a upstream. ktime_get and ktime_get_ts were calling timekeeping_get_ns() but later they were not calling arch_gettimeoffset() so architectures using this mechanism returned 0 ns when calling these functions. This happened for example when running Busybox's ping which calls syscall(__NR_clock_gettime, CLOCK_MONOTONIC, ts) which eventually calls ktime_get. As a result the returned ping travel time was zero. Signed-off-by: Hector Palacios Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman

genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier

2011-11-26T17:10:36Z

commit 9bab0b7fbaceec47d32db51cd9e59c82fb071f5a upstream This adds a mechanism to resume selected IRQs during syscore_resume instead of dpm_resume_noirq. Under Xen we need to resume IRQs associated with IPIs early enough that the resched IPI is unmasked and we can therefore schedule ourselves out of the stop_machine where the suspend/resume takes place. This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME". Back ported to 2.6.32 (which lacks syscore support) by calling the relavant resume function directly from sysdev_resume). v2: Fixed non-x86 build errors. Signed-off-by: Ian Campbell Cc: Rafael J. Wysocki Cc: Jeremy Fitzhardinge Cc: xen-devel Cc: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman