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SubjectRe: [PATCH -tip v3 00/23] kprobes: introduce NOKPROBE_SYMBOL() and general cleaning of kprobe blacklist
On Wed, 20 Nov 2013 12:36:00 -0500
"Frank Ch. Eigler" <fche@redhat.com> wrote:

> Hi -
>
> > > Does this new blacklist cover enough that the kernel now survives a
> > > broadly wildcarded perf-probe, e.g. over e.g. all of its kallsyms?
> >
> > That's generally the purpose of the annotations - if it doesn't then
> > that's a bug.
>
> AFAIK, no kernel since kprobes was introduced has ever stood up to
> that test. perf probe lacks the wildcarding powers of systemtap, so
> one needs to resort to something like:
>
> # cat /proc/kallsyms | grep ' [tT] ' | while read addr type symbol; do
> perf probe $symbol
> done

I'm curious to why one would do that. IIUC, perf now has function
tracing support.

-- Steve

>
> then wait for a few hours for that to finish. Then, or while the loop
> is still running, run
>
> # perf record -e 'probe:*' -aR sleep 1
>
> to take a kernel down.
>
>
> - FChE



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