netdev - Re: [PATCH bpf-next v4 0/5] Make probes which emit dmesg warnings optional

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Date:   Wed, 26 Feb 2020 18:36:50 +0100
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Quentin Monnet <quentin@...valent.com>,
        Michal Rostecki <mrostecki@...nsuse.org>, bpf@...r.kernel.org
Cc:     Alexei Starovoitov <ast@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        Andrii Nakryiko <andriin@...com>,
        Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Shuah Khan <shuah@...nel.org>,
        linux-kselftest@...r.kernel.org
Subject: Re: [PATCH bpf-next v4 0/5] Make probes which emit dmesg warnings
 optional

On 2/26/20 6:22 PM, Quentin Monnet wrote:
> 2020-02-26 17:59 UTC+0100 ~ Michal Rostecki <mrostecki@...nsuse.org>
>> Feature probes in bpftool related to bpf_probe_write_user and
>> bpf_trace_printk helpers emit dmesg warnings which might be confusing
>> for people running bpftool on production environments. This patch series
>> addresses that by filtering them out by default and introducing the new
>> positional argument "full" which enables all available probes.
>>
>> The main motivation behind those changes is ability the fact that some
>> probes (for example those related to "trace" or "write_user" helpers)
>> emit dmesg messages which might be confusing for people who are running
>> on production environments. For details see the Cilium issue[0].
>>
>> v1 -> v2:
>> - Do not expose regex filters to users, keep filtering logic internal,
>> expose only the "full" option for including probes which emit dmesg
>> warnings.
>>
>> v2 -> v3:
>> - Do not use regex for filtering out probes, use function IDs directly.
>> - Fix bash completion - in v2 only "prefix" was proposed after "macros",
>>    "dev" and "kernel" were not.
>> - Rephrase the man page paragraph, highlight helper function names.
>> - Remove tests which parse the plain output of bpftool (except the
>>    header/macros test), focus on testing JSON output instead.
>> - Add test which compares the output with and without "full" option.
>>
>> v3 -> v4:
>> - Use enum to check for helper functions.
>> - Make selftests compatible with older versions of Python 3.x than 3.7.
>>
>> [0] https://github.com/cilium/cilium/issues/10048
>>
>> Michal Rostecki (5):
>>    bpftool: Move out sections to separate functions
>>    bpftool: Make probes which emit dmesg warnings optional
>>    bpftool: Update documentation of "bpftool feature" command
>>    bpftool: Update bash completion for "bpftool feature" command
>>    selftests/bpf: Add test for "bpftool feature" command
>>
>>   .../bpftool/Documentation/bpftool-feature.rst |  19 +-
>>   tools/bpf/bpftool/bash-completion/bpftool     |   3 +-
>>   tools/bpf/bpftool/feature.c                   | 283 +++++++++++-------
>>   tools/testing/selftests/.gitignore            |   5 +-
>>   tools/testing/selftests/bpf/Makefile          |   3 +-
>>   tools/testing/selftests/bpf/test_bpftool.py   | 178 +++++++++++
>>   tools/testing/selftests/bpf/test_bpftool.sh   |   5 +
>>   7 files changed, 373 insertions(+), 123 deletions(-)
>>   create mode 100644 tools/testing/selftests/bpf/test_bpftool.py
>>   create mode 100755 tools/testing/selftests/bpf/test_bpftool.sh
>>
> 
> Reviewed-by: Quentin Monnet <quentin@...valent.com>
> (Please keep tags between versions.)
> 
> Your change looks good. The tests in patch 5 still pass with Python 3.7.5 (but I have not tried to run with an older version of Python).

Looks better now ...

# ./test_bpftool.sh
test_feature_dev_json (test_bpftool.TestBpftool) ... ok
test_feature_kernel (test_bpftool.TestBpftool) ... ok
test_feature_kernel_full (test_bpftool.TestBpftool) ... ok
test_feature_kernel_full_vs_not_full (test_bpftool.TestBpftool) ... ok
test_feature_macros (test_bpftool.TestBpftool) ... ok

----------------------------------------------------------------------
Ran 5 tests in 0.253s

OK

... applied, thanks!