* 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