Re: [PATCH 1/2 v2] tracing/arm64: Have max stack tracer handle the case of return address after data

Will Deacon
2019-08-08T17:12:01Z

On Thu, Aug 08, 2019 at 12:36:32PM -0400, Steven Rostedt wrote:
> On Thu, 8 Aug 2019 17:28:26 +0100
> Will Deacon <will@kernel.org> wrote:
>
> > > + * Note, this may change in the future, and we will need to deal with that
> > > + * if it were to happen.
> > > + */
> > > +#define ARCH_RET_ADDR_AFTER_LOCAL_VARS 1
> >
> > I know it's long already, but prefixing this with FTRACE_ would be good so
> > that other code doesn't use it for anything. It's not the end of the world
> > if the ftrace stack usage statistics are wonky, but if people tried to use
> > this for crazy things like livepatching then we'd be in trouble.
> >
> > Maybe FTRACE_ARCH_FRAME_AFTER_LOCALS, which is the same length as what
> > you currently have?
>
> Note, it would still need to be prefixed with "ARCH_" as that's the way
> of showing arch specific defines.
>
> We could make it more descriptive of what it will do and not the reason
> for why it is done...
>
>
> ARCH_FTRACE_SHIFT_STACK_TRACER

Acked-by: Will Deacon <will@kernel.org>

Thanks, Steve.

Will