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

[Peter Zijlstra]

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@xxxxxxxxxxx> wrote:
> 
> > On Sun, 5 Nov 2023 18:33:01 -0500
> > Steven Rostedt <rostedt@xxxxxxxxxxx> 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;
 };