Re: [RFC PATCH 24/32] x86/ftrace: Enable HAVE_FUNCTION_GRAPH_FREGS

Peter Zijlstra
2023-11-06T10:20:06Z

On Mon, Nov 06, 2023 at 09:38:50AM +0900, Masami Hiramatsu wrote:
> On Sun, 5 Nov 2023 18:34:09 -0500
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
> > On Sun, 5 Nov 2023 18:33:01 -0500
> > Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > > For x86_64, that would be:
> > >
> > > rdi, rsi, rdx, r8, r9, rsp
> >
> > I missed rcx.
>
> I would like to add rax to the list so that it can handle the return value too. :)

So something like so?

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 897cf02c20b1..71bfe27594a5 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -36,6 +36,10 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)

#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
struct ftrace_regs {
+ /*
+ * Partial, filled with:
+ * rax, rcx, rdx, rdi, rsi, r8, r9, rsp
+ */
struct pt_regs regs;
};