Messages in this thread | | | Date | Fri, 28 Jun 2013 18:07:11 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] perf tools: Fixup for removing -f option in perf record |
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* David Ahern <dsahern@gmail.com> wrote:
> On 6/28/13 9:37 AM, Ingo Molnar wrote: > > > >* David Ahern <dsahern@gmail.com> wrote: > > > >>On 6/28/13 3:47 AM, Jiri Olsa wrote: > >>>>>I thought -f was the implied default for ages? > >>>> > >>>>OK.. I've been dutifully typing it all this while :-) > >>> > >>>The '-f' option in record command had no affect.. myabe it got > >>>depreceated when we started to backup perf.data to perf.data.old..? > >> > >>Way back in 2010, 2.6.34 kernel - 7865e817 commit. I've been typing > >>the -f for while too. Now about the need for the pesky -f on the > >>analysis side.... > > > >That's only needed when perf.data is owned by a different user, right? > > > > Yes, why not let file permissions dictate of uid x can read uid y files? > Why does perf need to have that restriction? For example, QA collects > the data files, developers analyze them.
So, the thinking behind that is that user should not be able to generate a malicious perf.data file and let root (or another user) run it accidentally.
( That presumes some sort of exploitable parsing bug or other buffer overflow in perf. )
I don't feel terribly strongly about it though.
Thanks,
Ingo
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