Re: [PATCH] LoongArch: Make compute_return_era() return void

[Tiezhu Yang]

On 06/23/2022 05:26 PM, Huacai Chen wrote:
> Hi, Tiezhu,
>
> On Sat, Jun 18, 2022 at 4:39 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
> > compute_return_era() always returns 0, make it return void,
> > and then no need to check its return value for its callers.
> >
> > Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> > ---
> >  arch/loongarch/include/asm/branch.h | 3 +--
> >  arch/loongarch/kernel/traps.c       | 3 +--
> >  2 files changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/loongarch/include/asm/branch.h b/arch/loongarch/include/asm/branch.h
> > index 3f33c89..9a133e4 100644
> > --- a/arch/loongarch/include/asm/branch.h
> > +++ b/arch/loongarch/include/asm/branch.h
> > @@ -12,10 +12,9 @@ static inline unsigned long exception_era(struct pt_regs *regs)
> >         return regs->csr_era;
> >  }
> >
> > -static inline int compute_return_era(struct pt_regs *regs)
> > +static inline void compute_return_era(struct pt_regs *regs)
> >  {
> >         regs->csr_era += 4;
> > -       return 0;
> >  }
> >
> >  #endif /* _ASM_BRANCH_H */
> > diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
> > index e4060f8..1bf58c6 100644
> > --- a/arch/loongarch/kernel/traps.c
> > +++ b/arch/loongarch/kernel/traps.c
> > @@ -475,8 +475,7 @@ asmlinkage void noinstr do_ri(struct pt_regs *regs)
> >
> >         die_if_kernel("Reserved instruction in kernel code", regs);
> >
> > -       if (unlikely(compute_return_era(regs) < 0))
> > -               goto out;
> > +       compute_return_era(regs);
> Maybe it is better to simply remove the compute_return_era() function?

Good idea, if so, I think we can also remove exception_era(), and then
arch/loongarch/include/asm/branch.h can be removed.

If you are OK, I will send a v2 patch to remove
arch/loongarch/include/asm/branch.h

Thanks,
Tiezhu

> Huacai
> >         if (unlikely(get_user(opcode, era) < 0)) {
> >                 status = SIGSEGV;
> > --
> > 2.1.0