Re: [PATCH v1] LoongArch: Remove unnecessary checks in bt_address()

[Bibo Mao]

On 2025/12/10 上午9:28, Tiezhu Yang wrote:
> On 2025/12/9 下午4:30, Huacai Chen wrote:
> > Hi, Tiezhu,
> >
> > On Tue, Dec 9, 2025 at 2:18 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> 
> > wrote:
> > >
> ...
> > >          extern unsigned long eentry;
> > >
> > > -       if (__kernel_text_address(ra))
> > > -               return ra;
> > > -
> > > -       if (__module_text_address(ra))
> > > -               return ra;
> > I think the correct way is to remove the __module_text_address()
> > condition but keep the __kernel_text_address() condition. Then return
> > 0 at the end of this function, and remove the __kernel_text_address()
> > condition out of this function.
>
> It can not remove the check of __kernel_text_address() after calling
> bt_address() because it needs to validate the calculated address for
> exception, then no need to keep the __kernel_text_address() condition
> in bt_address() because it will check the PC outside bt_address().
        state->pc = bt_address(pc);
        if (!state->pc) {
                pr_err("cannot find unwind pc at %p\n", (void *)pc);
                goto err;
        }

        if (!__kernel_text_address(state->pc))
                goto err;
I guess that you both comes from different views :) one treats these 
piece of code into one, one only views function bt_address().

Especially with if (!state->pc), how could this happen?

Regards
Bibo Mao

> Thanks,
> Tiezhu