Re: [PATCH bpf-next 0/6] bpftool: Allow to select sections and filter probes

From: Daniel Borkmann
Date: Wed Feb 19 2020 - 11:52:31 EST

On 2/19/20 5:37 PM, Alexei Starovoitov wrote:
On Wed, Feb 19, 2020 at 4:33 AM Michal Rostecki <mrostecki@xxxxxxxxxxxx> wrote:

On 2/19/20 4:02 AM, Alexei Starovoitov wrote:
The motivation is clear, but I think the users shouldn't be made
aware of such implementation details. I think instead of filter_in/out
it's better to do 'full or safe' mode of probing.
By default it can do all the probing that doesn't cause
extra dmesgs and in 'full' mode it can probe everything.

Alright, then I will send later v2 where the "internal" implementation
(filtering out based on regex) stays similar (filter_out will stay in
the code without being exposed to users, filter_in will be removed). And
the exposed option of "safe" probing will just apply the
"(trace|write_user)" filter_out pattern. Does it sound good?

yes. If implementation is doing filter_in and applying 'trace_printk|write_user'
strings hidden within bpftool than I think it should be good.
What do you think the default should be?
It feels to me that the default should not be causing dmesg prints.
So only addition flag for bpftool command line will be 'bpftool
feature probe full'

Agree, that makes sense to me.