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Re: Blacklist regex is too general


On 04/12/2016 10:46 AM, Alexander Lochmann wrote:
> On 04/12/2016 05:41 PM, David Smith wrote:
>> On 04/12/2016 04:12 AM, Alexander Lochmann wrote:
>>> Hi folks!
>>>
>>> I've wanted to measure the impact of packet duplication due to a raw socket.
>>> To do so, I have to probe the kernel function 'raw_v4_input' in
>>> net/ipv4/raw.c.
>>> Unfortunately, the function name matches the regex defined at
>>> dwflpp:4324, which is: blfn += "|raw_.*";.
>>> On my opinion, the regex is too general, and there is no reason why it
>>> shouldn't be allowed to probe 'raw_v4_input'.
>>> It therefore might be necessary to rephrase the mentioned regex. :)
>>
>> While we think about the best way to proceed here, you should be able to
>> use '-g' (guru mode) to ignore the blacklist.
>>
> Ah. Thx. Good to know. :)
> Since I compile my own version, I simply commented that line out.

I went through several kernels trying to figure out what that blacklist
regular expression was supposed to protect us against, and couldn't find
anything. So, commit 0748ca7 removes that regexp.

<https://sourceware.org/git/gitweb.cgi?p=systemtap.git;a=commit;h=0748ca7c7d3fbfec536cc1c38fe3deab70007fef>

Thanks for the report.

-- 
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)


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