Re: [PATCH 3/8] signal/sparc: Document a conflict with SI_USER with SIGFPE

[ebiederm@xmission.com (Eric W. Biederman)]

ebiederm@xmission.com (Eric W. Biederman) writes:

> David Miller <davem@davemloft.net> writes:
>
>> From: "Eric W. Biederman" <ebiederm@xmission.com>
>> Date: Fri, 30 Jun 2017 07:39:01 -0500
>>
>>> diff --git a/arch/sparc/include/uapi/asm/siginfo.h b/arch/sparc/include/uapi/asm/siginfo.h
>>> index 2d9b79ccaa50..6bc5c677e92f 100644
>>> --- a/arch/sparc/include/uapi/asm/siginfo.h
>>> +++ b/arch/sparc/include/uapi/asm/siginfo.h
>>> @@ -17,6 +17,11 @@
>>>  #define SI_NOINFO	32767		/* no information in siginfo_t */
>>>  
>>>  /*
>>> + * SIGFPE si_codes
>>> + */
>>> +#define FPE_FIXME	(__SI_FAULT|0)	/* Broken dup of SI_USER */
>>> +
>>> +/*
>>>   * SIGEMT si_codes
>>>   */
>>>  #define EMT_TAGOVF	(__SI_FAULT|1)	/* tag overflow */
>>
>> It's one thing to say FIXME in a comment in a kernel local header or
>> C file.
>>
>> It's quite another to put this into the name of a macro which has
>> visibility in the global user compilation namespace.
>>
>> I don't think you should really do that.
>
> Good point.
>
> Sigh.   It almost fits because we did do something off in the uapi
> exported to userspace and we don't have a header file definition for
> that case.
>
> Still.  At this point arch/sparc/include/asm/siginfo.h is
> a better fit for that definition.
>
> I will respin and fix that.

Except arch/<arch>/include/asm/siginfo.h has now been eliminated.
So these definitions have to be
#ifdef __KERNEL__
#define ..._FIXME
#endif

In the uapi but not visible in the headers outside of the kernel.
Which seems appropriate for these values.

Eric