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Re: [PATCH -tip v8 10/26] kprobes/x86: Allow probe on some kprobe preparation functions
- From: Steven Rostedt <rostedt at goodmis dot org>
- To: Masami Hiramatsu <masami dot hiramatsu dot pt at hitachi dot com>
- Cc: linux-kernel at vger dot kernel dot org, Ingo Molnar <mingo at kernel dot org>, Andi Kleen <andi at firstfloor dot org>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Sandeepa Prabhu <sandeepa dot prabhu at linaro dot org>, Frederic Weisbecker <fweisbec at gmail dot com>, x86 at kernel dot org, fche at redhat dot com, mingo at redhat dot com, systemtap at sourceware dot org, "H. Peter Anvin" <hpa at zytor dot com>, Thomas Gleixner <tglx at linutronix dot de>, Andrew Morton <akpm at linux-foundation dot org>
- Date: Mon, 24 Mar 2014 15:35:56 -0400
- Subject: Re: [PATCH -tip v8 10/26] kprobes/x86: Allow probe on some kprobe preparation functions
- Authentication-results: sourceware.org; auth=none
- References: <20140305115843 dot 22766 dot 8355 dot stgit at ltc230 dot yrl dot intra dot hitachi dot co dot jp> <20140305115953 dot 22766 dot 53497 dot stgit at ltc230 dot yrl dot intra dot hitachi dot co dot jp>
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?
I guess not, but I just wanted to ask, as your test only tested the
start of function and not the middle of it.
-- 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
>