Messages in this thread | | | Date | Mon, 6 Nov 2023 22:06:17 -0500 | From | Steven Rostedt <> | Subject | Re: [RFC PATCH 24/32] x86/ftrace: Enable HAVE_FUNCTION_GRAPH_FREGS |
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On Tue, 7 Nov 2023 09:42:58 +0900 Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> Got it. So does ftrace_regs need a placeholder for direct trampoline? > (Or, can we use a register to pass it?) > I think we don't need to clear it for return_to_handler() but if > `ftrace_regs` spec requires it, it is better to do so.
It's per arch defined. I think I wrote somewhere that it just needs to pass back something that can tell if the handler is to return to a direct trampoline or not. It could be a unused register, or something else.
It's only needed if an architecture supports direct trampolines.
-- Steve
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