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From: "Björn Töpel" <bjorn@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
	olsajiri@gmail.com, ast@kernel.org, daniel@iogearbox.net
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, peterz@infradead.org, toke@redhat.com,
	David.Laight@aculab.com, rostedt@goodmis.org
Subject: Re: [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing
Date: Thu, 03 Nov 2022 14:42:01 +0100	[thread overview]
Message-ID: <875yfwrw7q.fsf@all.your.base.are.belong.to.us> (raw)
In-Reply-To: <20221103120012.717020618@infradead.org>

Peter Zijlstra <peterz@infradead.org> writes:

> Hi!
>
> Even thought the __attribute__((patchable_function_entry())) solution to the
> BPF dispatcher woes works, it turns out to not be supported by the whole range
> of ageing compilers we support. Specifically this attribute seems to be GCC-8
> and later.
>
> This is another approach -- using static_call() to rewrite the dispatcher
> function. I've compile tested this on:
>
>   x86_64  (inline static-call support)
>   i386    (out-of-line static-call support)
>   aargh64 (no static-call support)
>
> A previous version was tested and found working by Bjorn.
>
> It is split in two patches; first reverting the current approach and then
> introducing the new for ease of review.

Took it for a spin on x86_64/KVM. For the series:

Acked-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Björn Töpel <bjorn@kernel.org>

  parent reply	other threads:[~2022-11-03 13:43 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-03 12:00 [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing Peter Zijlstra
2022-11-03 12:00 ` [PATCH 1/2] bpf: Revert ("Fix dispatcher patchable function entry to 5 bytes nop") Peter Zijlstra
2022-11-03 12:00 ` [PATCH 2/2] bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace) Peter Zijlstra
2022-11-14 17:36   ` Steven Rostedt
2022-11-03 13:42 ` Björn Töpel [this message]
2022-11-03 14:48 ` [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing Jiri Olsa
2022-11-04 22:20 ` patchwork-bot+netdevbpf

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