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    Subject[PATCH 4.14 01/45] perf/core: Add sanity check to deal with pinned event failure
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Reinette Chatre <reinette.chatre@intel.com>

    commit befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7 upstream.

    It is possible that a failure can occur during the scheduling of a
    pinned event. The initial portion of perf_event_read_local() contains
    the various error checks an event should pass before it can be
    considered valid. Ensure that the potential scheduling failure
    of a pinned event is checked for and have a credible error.

    Suggested-by: Peter Zijlstra <peterz@infradead.org>
    Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Cc: fenghua.yu@intel.com
    Cc: tony.luck@intel.com
    Cc: acme@kernel.org
    Cc: gavin.hindman@intel.com
    Cc: jithu.joseph@intel.com
    Cc: dave.hansen@intel.com
    Cc: hpa@zytor.com
    Cc: stable@vger.kernel.org
    Link: https://lkml.kernel.org/r/6486385d1f30336e9973b24c8c65f5079543d3d3.1537377064.git.reinette.chatre@intel.com
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    kernel/events/core.c | 6 ++++++
    1 file changed, 6 insertions(+)

    --- a/kernel/events/core.c
    +++ b/kernel/events/core.c
    @@ -3757,6 +3757,12 @@ int perf_event_read_local(struct perf_ev
    goto out;
    }

    + /* If this is a pinned event it must be running on this CPU */
    + if (event->attr.pinned && event->oncpu != smp_processor_id()) {
    + ret = -EBUSY;
    + goto out;
    + }
    +
    /*
    * If the event is currently on this CPU, its either a per-task event,
    * or local to this CPU. Furthermore it means its ACTIVE (otherwise

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