Date: Thu, 4 Jan 2018 11:07:16 -0500
From: Josef Bacik <josef@toxicpanda.com>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>, Josef Bacik <jbacik@fb.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, daniel@iogearbox.net,
        linux-btrfs@vger.kernel.org, darrick.wong@oracle.com,
        Josef Bacik <josef@toxicpanda.com>,
        Akinobu Mita <akinobu.mita@gmail.com>
Subject: Re: [RFC PATCH bpf-next v2 0/4] Separate error injection table from
 kprobes
Message-ID: <20180104160715.7wz7pifbizkilisw@destiny>
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On Tue, Dec 26, 2017 at 04:46:28PM +0900, Masami Hiramatsu wrote:
> Hi Josef and Alexei,
> 
> Here are the 2nd version of patches to moving error injection
> table from kprobes. In this series I did a small fixes and
> add function-based fault injection.
> 
> Here is the previous version:
> 
> https://lkml.org/lkml/2017/12/22/554
> 
> There are 2 main reasons why I separate it from kprobes.
> 
>  - kprobes users can modify execution path not only at 
>    error-injection whitelist functions but also other
>    functions. I don't like to suggest user that such
>    limitation is from kprobes itself.
> 
>  - This error injection information is also useful for
>    ftrace (function-hook) and livepatch. It should not
>    be limited by CONFIG_KPROBES.
> 
> So I introduced CONFIG_FUNCTION_ERROR_INJECTION for this feature.
> Also CONFIG_FAIL_FUNCTION is added, which provides function-based
> error injection interface via debugfs following fault-injection
> framework. See [4/4].
> 
> Any thoughts?

Sorry Masami, I've been on vacation for the last two weeks.  This approach is
fine by me, if we want to allow other mechanisms other than bpf to use this
functionality then hooray.  I'll do a proper review when you post v3, just
wanted to let you know I wasn't ignoring you.  Thanks,

Josef