Re: [PATCH 0/2] arm64: ftrace: support DIRECT_CALLS without CALL_OPS

"Jose Fernandez (Anthropic)" <[email protected]> Wed, 12 Aug 2026 13:13:12 +0000

Newsgroups	dev.linux.lists.llvm,org.infradead.lists.linux-arm-kernel,org.kernel.vger.bpf,org.kernel.vger.linux-kernel,org.kernel.vger.linux-trace-kernel
Message-ID	<[email protected]>

On Wed, Jul 29, 2026 at 02:02:52PM +0000, Jose Fernandez (Anthropic) wrote:
> One idea I would like your opinion on is an in-range
> allocation preference for BPF trampolines, since execmem seems to
> have the shape for it on arm64 already.
[...]

Hi Mark,

Quick update on this, also for the others on the thread waiting on
the perf side. After some internal discussion we decided to try
adding CALL_OPS support on kCFI kernels directly, instead of the
in-range allocation above. The section argument Sami added to
-fpatchable-function-entry in clang 21 turns out to be enough to do
it with kernel changes only. We have it working as a local series and
I plan to send it as an RFC in the next couple of weeks. Mentioning
it now in case you are already looking at this or have thoughts
before then.

Thanks,
Jose