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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Masami Hiramatsu <mhiramat@kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, x86@kernel.org,
        Paul McKenney <paulmck@kernel.org>,
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Subject: Re: [patch V3 04/23] kprobes: Prevent probes in .noinstr.text section
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References: <20200320175956.033706968@linutronix.de> <20200320180032.799569116@linutronix.de> <20200323230025.a24f949a2143dbd5f208f00c@kernel.org> <87mu87oy7n.fsf@nanos.tec.linutronix.de> <20200324144953.eec3e73f249901582bdf564e@kernel.org>
Date:   Tue, 24 Mar 2020 10:47:30 +0100
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Masami Hiramatsu <mhiramat@kernel.org> writes:
> On Mon, 23 Mar 2020 17:03:24 +0100
> Thomas Gleixner <tglx@linutronix.de> wrote:
>> > @@ -2212,6 +2212,10 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>> >  	ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start,
>> >  					(unsigned long)__kprobes_text_end);
>> >  
>> > +	/* Symbols in noinstr section are blacklisted */
>> > +	ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start,
>> > +					(unsigned long)__noinstr_text_end);
>> > +
>> >  	return ret ? : arch_populate_kprobe_blacklist();
>> >  }
>> 
>> So that extra function is not required when adding that, right?
>
> That's right :)
>
>> 
>> >> +/* Functions in .noinstr.text must not be probed */
>> >> +static bool within_noinstr_text(unsigned long addr)
>> >> +{
>> >> +	/* FIXME: Handle module .noinstr.text */
>
> And this reminds me that the module .kprobes.text is not handled yet :(.

Correct. Any idea how to do that with a simple oneliner like the above?

Thanks,

        tglx