* David Miller <da...@davemloft.net> wrote:

> From: Josef Bacik <jo...@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

Reply via email to