Messages in this thread | | | Subject | Re: [PATCH v5 2/3] net: add kcov handle to skb extensions | From | Johannes Berg <> | Date | Sat, 21 Nov 2020 21:58:37 +0100 |
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On Sat, 2020-11-21 at 12:55 -0800, Jakub Kicinski wrote: > [snip] > Ack, you have to figure out all the places anyway, the question is > whether you put probes there or calls in the source code. > > Shifting the maintenance burden but also BPF is flexibility.
Yeah, true. Though I'd argue also visibility - this stuff is pretty simple now, if it gets into lots of lines of BPF code to track it that is maintained "elsewhere", we won't see the bugs in it :-)
And it's kinda a thing that we as kernel developers _should_ be the ones looking at since it's testing our code.
> Yup, the point is you can feed a raw skb pointer (and all other > possible context you may want) to a BPF prog in kcov_remote_start() > and let BPF/BTF give you the handle it recorded in its maps.
Yeah, it's possible. Personally, I don't think it's worth the complexity.
> It is more complicated. We can go back to an skb field if this work is > expected to yield results for mac80211. Would you mind sending a patch?
I can do that, but I'm not going to be able to do it now/tonight (GMT+1 here), so probably only Monday/Tuesday or so, sorry.
johannes
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