Messages in this thread | | | Date | Thu, 25 Aug 2016 11:08:14 -0500 | From | Josh Poimboeuf <> | Subject | Re: livepatch/kprobes incompatibility |
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On Wed, Aug 24, 2016 at 11:39:59AM +0200, Petr Mladek wrote: > + kretprobe is safe as well; the kprobe handler does not modify regs->ip; > it just modifies the return address from the function; it does not affect > livepatching because the address is defined by the function caller > and livepatching keeps it as is
BTW, I think there's still a kretprobe issue which affects the accuracy of the unwinder and the consistency model. The unwinder will report kretprobe_trampoline instead of the real caller's return address.
It can probably be fixed similarly to how ftrace function_graph tracing does it with a ftrace_graph_ret_addr() helper:
https://lkml.kernel.org/r/cover.1471607358.git.jpoimboe@redhat.com
-- Josh
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