Re: [PATCH v3 0/5] ARM64: Add kernel probes(Kprobes) support

From: Steve Capper
Date: Thu Dec 04 2014 - 05:21:43 EST

On 4 December 2014 at 02:48, David Long <dave.long@xxxxxxxxxx> wrote:
> On 12/03/14 20:16, William Cohen wrote:
> [...]
>> The perf issue seems to be independent and can be reproduced without using
>> any kprobe support. I need to get a simple reproducer and mention it on the
>> linux-perf-user list.
>> -Will
> OK, my confusion came from all the different things perf can use. I have
> not yet been able to reproduce the "perf stat" failure, but I do see the
> failure with Steve's example using tracepoints. I had thought that was
> using kprobes, but apparently it just uses tracepoints. These look like two
> different failures to me: One related to tracepoints, and one in the PMU
> driver.
> Since this seems unrelated to kprobes I don't plan on pursuing these
> particular problems.
> -dl

Sorry for the late reply...

The example I had was:
echo "p:memcpy memcpy %x2" > /sys/kernel/debug/tracing/kprobe_events
perf record -e kprobes:memcpy -a sleep 5

[then crash due to IRQs being unexpectedly disabled in the ext4 code]

Isn't that a kprobe problem?

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