Messages in this thread | | | Date | Wed, 9 Aug 2023 23:16:07 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [RFC PATCH v2 2/6] tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER |
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On Wed, 9 Aug 2023 12:29:13 +0200 Florent Revest <revest@chromium.org> wrote:
> On Mon, Aug 7, 2023 at 8:48 AM Masami Hiramatsu (Google) > <mhiramat@kernel.org> wrote: > > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > > index ce156c7704ee..3fb94a1a2461 100644 > > --- a/include/linux/ftrace.h > > +++ b/include/linux/ftrace.h > > @@ -112,11 +112,11 @@ static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *val > > } > > #endif > > > > -#ifdef CONFIG_FUNCTION_TRACER > > - > > -extern int ftrace_enabled; > > - > > -#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS > > +/* > > + * If the architecture doesn't support FTRACE_WITH_ARGS or disable function > > nit: disables*
Thanks!
> > > + * tracer, define the default(pt_regs compatible) ftrace_regs. > > + */ > > +#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) || !defined(CONFIG_FUNCTION_TRACER) > > I wonder if we should make things simpler with: > > #if defined(HAVE_PT_REGS_COMPAT_FTRACE_REGS) || !defined(CONFIG_FUNCTION_TRACER) > > And remove the ftrace_regs definitions that are copy-pastes of this > block in arch specific headers. Then we can enforce in a single point > that HAVE_PT_REGS_COMPAT_FTRACE_REGS holds.
Here, the "HAVE_PT_REGS_COMPAT_FTRACE_REGS" does not mean that the ftrace_regs is completely compatible with pt_regs, but on the memory it wraps struct pt_regs (thus we can just cast the type).
- CONFIG_DYNAMIC_FTRACE_WITH_REGS ftrace_regs is completely compatible with pt_regs
- CONFIG_DYNAMIC_FTRACE_WITH_ARGS | ftrace_regs may not compatible with pt_regs | +- CONFIG_HAVE_PT_REGS_COMPAT_FTRACE_REGS but on memory image, ftrace_regs includes pt_regs.
Thank you,
> > Maybe that's a question for Steven ?
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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