Subject: Re: Re: Re: [RFT PATCH -next v3] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

From: Masami Hiramatsu <[email-masked]>
Date: Thu, 19 Jun 2014 20:20:45 +0900

(2014/06/19 20:01), Masami Hiramatsu wrote:

>>>>> Ah, those messages should be shown in dmesg when booting if it doesn't work,
>>>>> because the messages are printed by initialization process of kprobe blacklist.
>>>>> So, reproducing it is just enabling CONFIG_KPROBES and boot it.
>>>> Well,  we don't get those messages on Power, since the kallsyms has the
>>>> entries for ".function_name". The correct way to verify is, either  :
>>>
>>> Hmm, that seems another issue on powerpc. Is that expected(and designed)
>>> behavior?
>> AFAIK, yes, it is.
>> To be more precise :
>>
>> we have 'foo' and '.foo' for a function foo(), where 'foo' points to the
>> function_entry and '.foo' points to the actual function.
> 
> Ah, I see. So if we run
> 
>   func_ptr p = foo;
>   return p == kallsyms_lookup_name(".foo");
> 
> it returns true.

One more thing I should know, is the address of ".function_name" within the
kernel text? In other words, does kernel_text_address() return true for that
address? If not, it's easy to verify the address.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: [email-masked]