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From: Daniel Borkmann <daniel@iogearbox.net>
To: Luigi Rizzo <rizzo@iet.unipi.it>
Cc: bpf@vger.kernel.org, kpsingh@chromium.org, will@kernel.org
Subject: Re: arch_prepare_bpf_trampoline() for arm ?
Date: Wed, 24 Feb 2021 22:01:45 +0100	[thread overview]
Message-ID: <6af0ab27-48f1-e389-d2f4-41b3c1db4a18@iogearbox.net> (raw)
In-Reply-To: <CA+hQ2+hhDG2JprNLaUdX4xgcihvchEda1aJuQN3jtJ3hYucDcQ@mail.gmail.com>

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.

> [1] kstats is an in-kernel also in the above repo and previously
> discussed at https://lwn.net/Articles/813303/


  reply	other threads:[~2021-02-24 21:02 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 [this message]
2021-02-24 21:25   ` Toke Høiland-Jørgensen
2021-02-25  7:59     ` Jean-Philippe Brucker
2021-02-24 21:30   ` KP Singh
2021-02-24 22:27     ` Daniel Borkmann

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