Re: [PATCH 0/2][v5] Add the ability to do BPF directed error injection

From: David Miller
Date: Fri Nov 10 2017 - 22:22:43 EST


From: Josef Bacik <josef@xxxxxxxxxxxxxx>
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.