Re: [PATCH] sh: traps: Fix kernel unaligned access fixup in branch delay slots

[Arnd Bergmann]

On Fri, Oct 23, 2026, at 09:15, Geert Uytterhoeven wrote:
> On Fri, 23 Oct 2026 at 09:09, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> On Fri, Oct 23, 2026, at 01:34, Florian Fuchs wrote:
>> > @@ -287,8 +287,10 @@ static inline int handle_delayslot(struct pt_regs *regs,
>> >       insn_size_t instruction;
>> >       void __user *addr = (void __user *)(regs->pc +
>> >               instruction_size(old_instruction));
>> > +     struct mem_access *insn_ma = user_mode(regs) ?
>> > +             &user_mem_access : &kernel_mem_access;
>> >
>> > -     if (copy_from_user(&instruction, addr, sizeof(instruction))) {
>> > +     if (insn_ma->from(&instruction, addr, sizeof(instruction))) {
>> >               /* the instruction-fetch faulted */
>> >               if (user_mode(regs))
>> >                       return -EFAULT;
>>
>> The "insn_ma" pointer is always the same as the 'ma' argument
>> you already pass, as both are set based on 'user_mode(regs)'.
>> Why not just use the pointer you already have?
>
> That would also handle handle_trapped_io(), which passes
> &trapped_io_access, right?

Indeed, that would be bad. The patch looks fine then.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>