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    SubjectRe: [PATCH 0/2] kprobes: Fix kretprobe incorrect stacking order problem
    On Mon, 7 Jan 2019 19:34:44 +0100
    Andrea Righi <righi.andrea@gmail.com> wrote:

    > On Mon, Jan 07, 2019 at 10:31:34PM +0900, Masami Hiramatsu wrote:
    > ...
    > > BTW, this is not all of issues. To remove CONFIG_KPROBE_EVENTS_ON_NOTRACE
    > > I'm trying to find out other notrace functions which can cause
    > > kernel crash by probing. Mostly done on x86, so I'll post it
    > > after this series.
    >
    > Not sure if you found it already, but it looks like some of the
    > _raw_spin_lock/unlock* functions (when they're not inlined) are causing
    > the same problem (or something similar), I can deadlock the system by
    > doing this for example:
    >
    > echo "r:event_1 __fdget" >> kprobe_events
    > echo "r:event_2 _raw_spin_lock_irqsave" >> kprobe_events
    > echo 1 > events/kprobes/enable
    > [DEADLOCK]
    >
    > Sending the following just in case...
    >

    Ug, kretprobe calls spinlocks in the callback? I wonder if we can
    remove them.

    I'm guessing this is a different issue than the one that this patch
    fixes. This sounds like we are calling kretprobe from kretprobe?

    -- Steve

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