Re: [RFC PATCH] m68k: Avoid CONFIG_COLDFIRE switch in uapi header

[Thomas Huth <thuth@redhat.com>]

On 14/11/2023 15.20, Greg Ungerer wrote:
> 
> 
> On 10/11/23 21:19, Arnd Bergmann wrote:
>> On Fri, Nov 10, 2023, at 11:31, Thomas Huth wrote:
>>> We should not use any CONFIG switches in uapi headers since
>>> these only work during kernel compilation. They are not defined
>>> for userspace. Let's use the __mcoldfire__ switch from the
>>> compiler here instead.
>>>
>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>   Marked as RFC since I didn't test it - I'd appreciate if someone
>>>   could give it a try on a real system.
>>>
>>>   arch/m68k/include/uapi/asm/ptrace.h | 2 +-
>>>   scripts/headers_install.sh          | 1 -
>>>   2 files changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/arch/m68k/include/uapi/asm/ptrace.h
>>> b/arch/m68k/include/uapi/asm/ptrace.h
>>> index 5b50ea592e00..ebd9fccb3d11 100644
>>> --- a/arch/m68k/include/uapi/asm/ptrace.h
>>> +++ b/arch/m68k/include/uapi/asm/ptrace.h
>>> @@ -39,7 +39,7 @@ struct pt_regs {
>>>     long     d0;
>>>     long     orig_d0;
>>>     long     stkadj;
>>> -#ifdef CONFIG_COLDFIRE
>>> +#ifdef __mcoldfire__
>>>     unsigned format :  4; /* frame format specifier */
>>>     unsigned vector : 12; /* vector offset */
>>>     unsigned short sr;
>>
>> I think this should be harmless,
> 
> I expect it would be, we have done this in at least one other uapi file,
> arch/m68k/include/uapi/asm/swab.h.
> 
> 
>> but I'm not sure we even
>> need the structure in a uapi header: about half the architectures
>> define this in a user-visible way, while the others don't.
>>
>> On csky, powerpc and microblaze, pt_regs is used inside
>> of the 'struct sigcontext' definition, but I don't think
>> this was ever the case on m68k.
>>
>> The other one that is accessed in userspace is 'struct
>> user_regs_struct', but this one is actually not in the
>> uapi headers on m68k or x86.
> 
> I don't think we need them in the uapi header at all. Trivially moving
> those 2 structures into the non-uapi ptrace.h seems to build fine on
> most simple setups I tried (systems using uClibc, with applications like
> strace). Should we try moving them out?

Yes, please! Can you send your patch?

  Thomas