[PATCH for-next] riscv: Fix default misaligned access trap

[Jesse T]

On Fri, Nov 8, 2024 at 5:09 PM Jesse T <mr.bossman075 at gmail.com> wrote:
>
> On Thu, Nov 7, 2024 at 5:38 PM Charlie Jenkins <charlie at rivosinc.com> wrote:
> >
> > Commit d1703dc7bc8e ("RISC-V: Detect unaligned vector accesses
> > supported") removed the default handlers for handle_misaligned_load()
> > and handle_misaligned_store(). When the kernel is compiled without
> > RISCV_SCALAR_MISALIGNED
> Technically CONFIG_RISCV_MISALIGNED.
> I apparently changed `+obj-y += traps_misaligned.o` to
> `+obj-$(CONFIG_RISCV_MISALIGNED) += traps_misaligned.o`
> in V2 and didn't change that check back oops sorry.
>
> > , these handlers are never defined, causing
> > compilation errors.
> >
> > Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
> Signed-off-by: Jesse Taube <mr.bossman075 at gmail.com>
>
> > Fixes: d1703dc7bc8e ("RISC-V: Detect unaligned vector accesses supported")
> > ---
> >  arch/riscv/include/asm/entry-common.h | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/arch/riscv/include/asm/entry-common.h b/arch/riscv/include/asm/entry-common.h
> > index 7b32d2b08bb6..c2808561df81 100644
> > --- a/arch/riscv/include/asm/entry-common.h
> > +++ b/arch/riscv/include/asm/entry-common.h
> > @@ -25,7 +25,19 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
> >  void handle_page_fault(struct pt_regs *regs);
> >  void handle_break(struct pt_regs *regs);
> >
> > +#ifdef CONFIG_RISCV_SCALAR_MISALIGNED

Meant to say to change this to CONFIG_RISCV_MISALIGNED.
As they are defined when CONFIG_RISCV_SCALAR_MISALIGNED is false
and CONFIG_RISCV_VECTOE_MISALIGNED is true. they are only not defined when
CONFIG_RISCV_SCALAR_MISALIGNED is false.

> >  int handle_misaligned_load(struct pt_regs *regs);
> >  int handle_misaligned_store(struct pt_regs *regs);
> > +#else
> > +static inline int handle_misaligned_load(struct pt_regs *regs)
> > +{
> > +       return -1;
> > +}
> > +
> > +static inline int handle_misaligned_store(struct pt_regs *regs)
> > +{
> > +       return -1;
> > +}
> > +#endif
> >
> >  #endif /* _ASM_RISCV_ENTRY_COMMON_H */
> >
> > ---
> > base-commit: 74741a050b79d31d8d2eeee12c77736596d0a6b2
> > change-id: 20241107-fix_handle_misaligned_load-8be86cb0806e
> > --
> > - Charlie
> >