From: Daniel Borkmann <daniel@iogearbox.net>
To: Josef Bacik <josef@toxicpanda.com>,
rostedt@goodmis.org, mingo@redhat.com, davem@davemloft.net,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
ast@kernel.org, kernel-team@fb.com
Cc: Josef Bacik <jbacik@fb.com>
Subject: Re: [PATCH 1/2] bpf: add a bpf_override_function helper
Date: Thu, 02 Nov 2017 02:08:10 +0100 [thread overview]
Message-ID: <59FA6FFA.1080503@iogearbox.net> (raw)
In-Reply-To: <1509555643-2899-2-git-send-email-josef@toxicpanda.com>
On 11/01/2017 06:00 PM, Josef Bacik wrote:
> From: Josef Bacik <jbacik@fb.com>
>
> Error injection is sloppy and very ad-hoc. BPF could fill this niche
> perfectly with it's kprobe functionality. We could make sure errors are
> only triggered in specific call chains that we care about with very
> specific situations. Accomplish this with the bpf_override_funciton
> helper. This will modify the probe'd callers return value to the
> specified value and set the PC to an override function that simply
> returns, bypassing the originally probed function. This gives us a nice
> clean way to implement systematic error injection for all of our code
> paths.
>
> Signed-off-by: Josef Bacik <jbacik@fb.com>
Looks useful (seccomp/BPF has something similar but on syscall level).
I think given we change kernel behavior, it would be good if we emit
similar warning like in case of bpf_get_probe_write_proto(), such that
from staring at the log (e.g. in case of subsequent crash), it could
help identifying that cause to trigger the bug could have been due to
bpf_override_function().
next prev parent reply other threads:[~2017-11-02 1:08 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 17:00 [PATCH 0/2][v3] Add the ability to do BPF directed error injection Josef Bacik
2017-11-01 17:00 ` [PATCH 1/2] bpf: add a bpf_override_function helper Josef Bacik
2017-11-01 17:18 ` Alexei Starovoitov
2017-11-02 1:08 ` Daniel Borkmann [this message]
2017-11-01 17:00 ` [PATCH 2/2] samples/bpf: add a test for bpf_override_return Josef Bacik
2017-11-01 17:23 ` Alexei Starovoitov
-- strict thread matches above, loose matches on Subject: below --
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
2017-11-02 14:37 [PATCH 0/2][v4] Add the ability to do BPF directed error injection Josef Bacik
2017-11-02 14:37 ` [PATCH 1/2] bpf: add a bpf_override_function helper Josef Bacik
2017-11-02 23:12 ` Daniel Borkmann
2017-11-03 14:31 ` Josef Bacik
2017-11-03 16:52 ` Daniel Borkmann
2017-11-03 21:07 ` Alexei Starovoitov
2017-10-31 15:45 [PATCH 0/2][v2] Add the ability to do BPF directed error injection Josef Bacik
2017-10-31 15:45 ` [PATCH 1/2] bpf: add a bpf_override_function helper Josef Bacik
2017-11-01 4:47 ` Alexei Starovoitov
2017-10-30 21:19 [PATCH 0/2] Add the ability to do BPF directed error injection Josef Bacik
2017-10-30 21:19 ` [PATCH 1/2] bpf: add a bpf_override_function helper Josef Bacik
2017-10-31 1:35 ` Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=59FA6FFA.1080503@iogearbox.net \
--to=daniel@iogearbox.net \
--cc=ast@kernel.org \
--cc=davem@davemloft.net \
--cc=jbacik@fb.com \
--cc=josef@toxicpanda.com \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox