From: Alexei Starovoitov via iovisor-dev <iovisor-dev-9jONkmmOlFHEE9lA1F8Ukti2O/JbrIOy@public.gmane.org>
To: Edward Cree <ecree-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>,
<davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>,
Alexei Starovoitov
<alexei.starovoitov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Daniel Borkmann <daniel-FeC+5ew28dpmcu3hnIyYJQ@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
iovisor-dev
<iovisor-dev-9jONkmmOlFHEE9lA1F8Ukti2O/JbrIOy@public.gmane.org>
Subject: Re: [PATCH net-next 2/4] bpf/verifier: remove varlen_map_value_access flag
Date: Tue, 22 Aug 2017 08:17:27 -0700 [thread overview]
Message-ID: <32c86ed1-c94e-ce9b-0639-17f597cd3d61@fb.com> (raw)
In-Reply-To: <6174b732-0bf9-19a3-09c4-f6a62be24a0c-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
On 8/22/17 6:26 AM, Edward Cree wrote:
> The optimisation it does is broken when the 'new' register value has a
> variable offset and the 'old' was constant. I broke it with my pointer
> types unification (see Fixes tag below), before which the 'new' value
> would have type PTR_TO_MAP_VALUE_ADJ and would thus not compare equal;
> other changes in that patch mean that its original behaviour (ignore
> min/max values) cannot be restored.
> Tests on a sample set of cilium programs show no change in count of
> processed instructions.
>
> Fixes: f1174f77b50c ("bpf/verifier: rework value tracking")
> Signed-off-by: Edward Cree <ecree-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
Acked-by: Alexei Starovoitov <ast-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
next prev parent reply other threads:[~2017-08-22 15:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-22 13:17 [PATCH net-next 0/4] bpf: verifier fixes Edward Cree
2017-08-22 13:27 ` [PATCH net-next 3/4] bpf/verifier: when pruning a branch, ignore its write marks Edward Cree
[not found] ` <d1a5b78a-8f5c-50d9-08a2-eb7c4829a478-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2017-08-22 15:24 ` Alexei Starovoitov via iovisor-dev
[not found] ` <0ba423e6-8629-37b1-b772-0734f1fb5489-b10kYP2dOMg@public.gmane.org>
2017-08-22 15:50 ` Edward Cree via iovisor-dev
2017-08-22 18:03 ` Edward Cree
[not found] ` <9a8076d1-a88b-b0e8-3c47-969a022feb60-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2017-08-22 18:25 ` Alexei Starovoitov via iovisor-dev
[not found] ` <f25f46bd-27cb-2182-2551-2887757c1e0f-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2017-08-22 13:26 ` [PATCH net-next 1/4] selftests/bpf: add a test for a pruning bug in the verifier Edward Cree via iovisor-dev
2017-08-22 13:26 ` [PATCH net-next 2/4] bpf/verifier: remove varlen_map_value_access flag Edward Cree via iovisor-dev
[not found] ` <6174b732-0bf9-19a3-09c4-f6a62be24a0c-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2017-08-22 15:17 ` Alexei Starovoitov via iovisor-dev [this message]
2017-08-22 13:27 ` [PATCH net-next 4/4] bpf/verifier: document liveness analysis Edward Cree via iovisor-dev
2017-08-22 15:42 ` Alexei Starovoitov
2017-08-22 15:55 ` Edward Cree
2017-08-22 15:59 ` Alexei Starovoitov
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