From: Ingo Molnar <mingo@kernel.org>
To: David Miller <davem@davemloft.net>
Cc: josef@toxicpanda.com, rostedt@goodmis.org, mingo@redhat.com,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
ast@kernel.org, kernel-team@fb.com, daniel@iogearbox.net
Subject: Re: [PATCH 0/2][v5] Add the ability to do BPF directed error injection
Date: Sat, 11 Nov 2017 09:16:00 +0100 [thread overview]
Message-ID: <20171111081600.ur3bkm5qyiomlpfa@gmail.com> (raw)
In-Reply-To: <20171111.121830.2006427570087282446.davem@davemloft.net>
* David Miller <davem@davemloft.net> wrote:
> From: Josef Bacik <josef@toxicpanda.com>
> Date: Tue, 7 Nov 2017 15:28:41 -0500
>
> > I'm sending this through Dave since it'll conflict with other BPF changes in his
> > tree, but since it touches tracing as well Dave would like a review from
> > somebody on the tracing side.
> ...
> > A lot of our error paths are not well tested because we have no good way of
> > injecting errors generically. Some subystems (block, memory) have ways to
> > inject errors, but they are random so it's hard to get reproduceable results.
> >
> > With BPF we can add determinism to our error injection. We can use kprobes and
> > other things to verify we are injecting errors at the exact case we are trying
> > to test. This patch gives us the tool to actual do the error injection part.
> > It is very simple, we just set the return value of the pt_regs we're given to
> > whatever we provide, and then override the PC with a dummy function that simply
> > returns.
> >
> > Right now this only works on x86, but it would be simple enough to expand to
> > other architectures. Thanks,
>
> Series applied, thanks Josef.
Please don't apply it yet as the series is still under active discussion - for now
I'm NAK-ing the x86 bits because I have second thoughts about the whole premise of
the feature being added here.
Thanks,
Ingo
next prev parent reply other threads:[~2017-11-11 8:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-07 20:28 [PATCH 0/2][v5] Add the ability to do BPF directed error injection Josef Bacik
2017-11-07 20:28 ` [PATCH 1/2] bpf: add a bpf_override_function helper Josef Bacik
2017-11-08 2:28 ` Daniel Borkmann
2017-11-10 9:34 ` Ingo Molnar
2017-11-10 17:14 ` Josef Bacik
2017-11-11 8:14 ` Ingo Molnar
2017-11-11 11:51 ` Josef Bacik
2017-11-12 6:49 ` Alexei Starovoitov
2017-11-12 10:38 ` Ingo Molnar
2017-11-13 15:57 ` Josef Bacik
2017-11-15 7:34 ` Ingo Molnar
2017-11-07 20:28 ` [PATCH 2/2] samples/bpf: add a test for bpf_override_return Josef Bacik
2017-11-08 2:29 ` Daniel Borkmann
2017-11-07 21:43 ` [PATCH 0/2][v5] Add the ability to do BPF directed error injection Alexei Starovoitov
2017-11-10 9:06 ` David Miller
2017-11-10 9:20 ` Peter Zijlstra
2017-11-11 3:18 ` David Miller
2017-11-11 8:16 ` Ingo Molnar [this message]
2017-11-11 9:25 ` David Miller
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