Re: [BUG] perf: bogus correlation of kernel symbols

[Stephane Eranian]

On Thu, May 12, 2011 at 11:36 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
>
> * Stephane Eranian <eranian@xxxxxxxxxx> wrote:
>
>> > The bug is that perf doesn't say "I can't match kernel symbols", but
>> > instead does some crazy matching and gives total crap module information (I
>> > think it just picks the one that shows up last in /proc/kallsyms).
>>
>> But I agree perf must not silently return bogus information. It should print
>> a big warning message and/or fallback to printing the raw addresses. [...]
>
> Yes, agreed, this is a bug in perf. I found out about this about two weeks ago
> and reported it to Arnaldo, but he is away right now - he might be able to fix
> it next week the earliest.
>
>> [...]ÂSo much for having perf in the kernel source tree to keep thingsÂin
>> sync...
>
> What do you mean?
>
I meant that when this kptr feature was added, people should have scanned the
entire tree (include tools/perf) to look for potential impact on
programs relying
on /proc/kallsyms. Having perf in the tree should have made this easier to
catch. That's all.



> Thanks,
>
> Â Â Â ÂIngo
>
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