| Date | Tue, 25 Mar 2014 18:20:26 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH -tip v8 10/26] kprobes/x86: Allow probe on some kprobe preparation functions |
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(2014/03/25 4:35), Steven Rostedt wrote: > On Wed, 05 Mar 2014 20:59:53 +0900 > Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote: > >> There is no need to prohibit probing on the functions >> used in preparation phase. Those are safely probed because >> those are not invoked from breakpoint/fault/debug handlers, >> there is no chance to cause recursive exceptions. >> >> Following functions are now removed from the kprobes blacklist. >> can_boost >> can_probe >> can_optimize >> is_IF_modifier >> __copy_instruction >> copy_optimized_instructions >> arch_copy_kprobe >> arch_prepare_kprobe >> arch_arm_kprobe >> arch_disarm_kprobe >> arch_remove_kprobe > > Is there any possibility that the arm and disarm could cause issues if > we have a probe in the middle of setting it?
No problem at least on x86, since we need to take a text_mutex for arm/disarm, those must not be called from int3/debug interrupts.
> I guess not, but I just wanted to ask, as your test only tested the > start of function and not the middle of it.
No I've not tested yet. OK, I'll test it and report.
Thank you,
> > -- Steve > > >> arch_trampoline_kprobe >> arch_prepare_kprobe_ftrace >> arch_prepare_optimized_kprobe >> arch_check_optimized_kprobe >> arch_within_optimized_kprobe >> __arch_remove_optimized_kprobe >> arch_remove_optimized_kprobe >> arch_optimize_kprobes >> arch_unoptimize_kprobe >> > >
-- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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