From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH 0/2][v5] Add the ability to do BPF directed error
 injection
Date: Sat, 11 Nov 2017 12:18:30 +0900 (KST)
Message-ID: <20171111.121830.2006427570087282446.davem@davemloft.net>
References: <1510086523-8859-1-git-send-email-josef@toxicpanda.com>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: 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
To: josef@toxicpanda.com
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <1510086523-8859-1-git-send-email-josef@toxicpanda.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

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.