Re: [PATCH 2/4] LoongArch: Add prologue unwinder support

[Youling Tang]

On 08/01/2022 11:26 PM, Huacai Chen wrote:
> > diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h
> > index 243330b39d0d..f9f73a26504e 100644
> > --- a/arch/loongarch/include/asm/unwind.h
> > +++ b/arch/loongarch/include/asm/unwind.h
> > @@ -14,6 +14,14 @@
> >  struct unwind_state {
> >         struct stack_info stack_info;
> >         struct task_struct *task;
> > +#if defined(CONFIG_UNWINDER_PROLOGUE)
> > +       unsigned long ra;
> > +       bool enable;
> > +       /*
> > +        * Enable is the prologue analysis method
> > +        * otherwise is the way to guess.
> > +        */
> > +#endif
> >         unsigned long sp, pc;
> >         bool first;
> >         bool error;
> This data struct makes me very uncomfortable, especially "enable" and
> the #ifdef, maybe we can rework it like this?
>
> #define UNWINDER_GUESS     0
> #define UNWINDER_PROLOGURE 1

Maybe it's better to define with enum type?
enum unwind_type {
	UNWINDER_GUESS,
	UNWINDER_PROLOGURE,
};

Youling

> struct unwind_state {
>         char type; /* UNWINDER_xxx */
>         bool first, error;
>         unsigned long sp, pc, ra;
>         struct task_struct *task;
>         struct stack_info stack_info;
> };
>
> Huacai