netdev - Re: [PATCH bpf] net/bpfilter: specify the log level for the kmsg message

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Date:   Wed, 23 Jun 2021 10:57:44 +0400
From:   Dmitrii Banshchikov <me@...que.spb.ru>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:     Gary Lin <glin@...e.com>, Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        bpf <bpf@...r.kernel.org>,
        Network Development <netdev@...r.kernel.org>,
        Martin Loviska <mloviska@...e.com>
Subject: Re: [PATCH bpf] net/bpfilter: specify the log level for the kmsg
 message

On Tue, Jun 22, 2021 at 09:38:38PM -0700, Alexei Starovoitov wrote:
> On Tue, Jun 22, 2021 at 9:09 PM Gary Lin <glin@...e.com> wrote:
> >
> > Per the kmsg document(*), if we don't specify the log level with a
> > prefix "<N>" in the message string, the default log level will be
> > applied to the message. Since the default level could be warning(4),
> > this would make the log utility such as journalctl treat the message,
> > "Started bpfilter", as a warning. To avoid confusion, this commit adds
> > the prefix "<5>" to make the message always a notice.
> >
> > (*) https://www.kernel.org/doc/Documentation/ABI/testing/dev-kmsg
> >
> > Fixes: 36c4357c63f3 ("net: bpfilter: print umh messages to /dev/kmsg")
> > Reported-by: Martin Loviska <mloviska@...e.com>
> > Signed-off-by: Gary Lin <glin@...e.com>
> > ---
> >  net/bpfilter/main.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/bpfilter/main.c b/net/bpfilter/main.c
> > index 05e1cfc1e5cd..291a92546246 100644
> > --- a/net/bpfilter/main.c
> > +++ b/net/bpfilter/main.c
> > @@ -57,7 +57,7 @@ int main(void)
> >  {
> >         debug_f = fopen("/dev/kmsg", "w");
> >         setvbuf(debug_f, 0, _IOLBF, 0);
> > -       fprintf(debug_f, "Started bpfilter\n");
> > +       fprintf(debug_f, "<5>Started bpfilter\n");
> >         loop();
> >         fclose(debug_f);
> >         return 0;
> 
> Adding Dmitrii who is redesigning the whole bpfilter.

Thanks. The same logic already exists in the bpfilter v1 patchset
- [1].

1. https://lore.kernel.org/bpf/c72bac57-84a0-ac4c-8bd8-08758715118e@fb.com/T/#mb36e20c4e5e4a70746bd50a109b1630687990214



-- 

Dmitrii Banshchikov