From: Peter Zijlstra <peterz@infradead.org>
To: 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, bjorn@kernel.org,
toke@redhat.com, David.Laight@aculab.com, rostedt@goodmis.org
Subject: [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing
Date: Thu, 03 Nov 2022 13:00:12 +0100 [thread overview]
Message-ID: <20221103120012.717020618@infradead.org> (raw)
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.
next reply other threads:[~2022-11-03 12:09 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-03 12:00 Peter Zijlstra [this message]
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 ` [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing Björn Töpel
2022-11-03 14:48 ` Jiri Olsa
2022-11-04 22:20 ` patchwork-bot+netdevbpf
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