From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Sebastiano Miano <sebastiano.miano@polito.it>,
netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
mingo@redhat.com, rostedt@goodmis.org, fulvio.risso@polito.it,
"David S. Miller" <davem@davemloft.net>,
brouer@redhat.com
Subject: Re: [bpf-next PATCH 3/3] bpf: add sample program to trace map events
Date: Mon, 23 Apr 2018 22:22:38 +0200 [thread overview]
Message-ID: <20180423222238.2636bdc8@redhat.com> (raw)
In-Reply-To: <20180423200801.m2kcrjcoavuibbmk@ast-mbp>
On Mon, 23 Apr 2018 14:08:02 -0600
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> On Mon, Apr 23, 2018 at 04:08:36PM +0200, Sebastiano Miano wrote:
> >
> > That's in fact the real use case for the first two patches. Since bpf
> > tracepoints are still a rather common (and easy to use) troubleshooting and
> > monitoring tool why shouldn't we "enhance" their support with the newly
> > added map/prog IDs?
>
> because these tracepoints can be abused in the way that this patch demonstrated.
> Whether to keep this patch in the series or not is irrelevant.
I don't understand your abuse use-case, can you explain what you mean?
You do realize that these tracepoints can _only_ monitor the userspace
map activity (not kernel map changes) ... and we _do_ need a way to
debug this (and without the map_id I can tell which map).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
prev parent reply other threads:[~2018-04-23 20:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-18 15:30 [bpf-next PATCH 0/3] Add ID to bpf_map/prog tracepoints Sebastiano Miano
2018-04-18 15:30 ` [bpf-next PATCH 1/3] bpf: add id to map tracepoint Sebastiano Miano
2018-04-19 9:08 ` Jesper Dangaard Brouer
2018-04-18 15:30 ` [bpf-next PATCH 2/3] bpf: add id to prog tracepoint Sebastiano Miano
2018-04-19 9:10 ` Jesper Dangaard Brouer
2018-04-18 15:30 ` [bpf-next PATCH 3/3] bpf: add sample program to trace map events Sebastiano Miano
2018-04-19 9:20 ` Jesper Dangaard Brouer
2018-04-20 0:27 ` Alexei Starovoitov
2018-04-20 9:47 ` Jesper Dangaard Brouer
2018-04-23 14:08 ` Sebastiano Miano
2018-04-23 20:08 ` Alexei Starovoitov
2018-04-23 20:22 ` Jesper Dangaard Brouer [this message]
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