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From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Luigi Rizzo <rizzo@iet.unipi.it>,
	bpf@vger.kernel.org, kpsingh@chromium.org, will@kernel.org
Subject: Re: arch_prepare_bpf_trampoline() for arm ?
Date: Thu, 25 Feb 2021 08:59:14 +0100	[thread overview]
Message-ID: <YDdY0gdKftxXZeMN@myrica> (raw)
In-Reply-To: <87blc92m5p.fsf@toke.dk>

On Wed, Feb 24, 2021 at 10:25:38PM +0100, Toke Høiland-Jørgensen wrote:
> Daniel Borkmann <daniel@iogearbox.net> writes:
> 
> > On 2/24/21 8:54 PM, Luigi Rizzo wrote:
> >> I prepared a BPF version of kstats[1]
> >> https://github.com/luigirizzo/lr-cstats
> >> that uses fentry/fexit hooks to monitor the execution time
> >> of a kernel function.
> >> 
> >> I hoped to have it working on ARM64 too, but it looks like
> >> arch_prepare_bpf_trampoline() only exists for x86.
> >> 
> >> Is there any outstanding patch for this function on ARM64,
> >> or any similar function I could look at to implement it myself ?
> >
> > Not that I'm currently aware of, arm64 support would definitely be great
> > to have. From x86 side, the underlying arch dependency was basically on
> > text_poke_bp() to patch instructions on a live kernel. Haven't checked
> > recently whether an equivalent exists on arm64 yet, but perhaps Will
> > might know.
> 
> Adding Jean-Philippe; I believe he is/was working on this...?

Yes, I have a very rough prototype here:
https://jpbrucker.net/git/linux/log/?h=bpf/devel

But not a ton of time to work on it at the moment, I don't know when I'll
be able to post something.

Thanks,
Jean


  reply	other threads:[~2021-02-25  8:00 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-24 19:54 arch_prepare_bpf_trampoline() for arm ? Luigi Rizzo
2021-02-24 21:01 ` Daniel Borkmann
2021-02-24 21:25   ` Toke Høiland-Jørgensen
2021-02-25  7:59     ` Jean-Philippe Brucker [this message]
2021-02-24 21:30   ` KP Singh
2021-02-24 22:27     ` Daniel Borkmann

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