Re: [PATCH 13/22] x86: FRED enumerations

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

On 2025-08-14 21:44, Andrew Cooper wrote:
> On 14/08/2025 8:37 pm, Nicola Vetrini wrote:
>> On 2025-08-14 13:47, Andrew Cooper wrote:
>>> On 14/08/2025 12:44 pm, Jan Beulich wrote:
>>>> On 14.08.2025 13:42, Andrew Cooper wrote:
>>>>> On 14/08/2025 12:20 pm, Jan Beulich wrote:
>>>>>> On 08.08.2025 22:23, Andrew Cooper wrote:
>>>>>>> --- a/xen/arch/x86/include/asm/x86-defns.h
>>>>>>> +++ b/xen/arch/x86/include/asm/x86-defns.h
>>>>>>> @@ -75,6 +75,7 @@
>>>>>>>  #define X86_CR4_PKE        0x00400000 /* enable PKE */
>>>>>>>  #define X86_CR4_CET        0x00800000 /* Control-flow
>>>>>>> Enforcement Technology */
>>>>>>>  #define X86_CR4_PKS        0x01000000 /* Protection Key
>>>>>>> Supervisor */
>>>>>>> +#define X86_CR4_FRED      0x100000000 /* Fast Return and Event
>>>>>>> Delivery */
>>>>>> ... a UL suffix added here for Misra.
>>>>> I was surprised, but Eclair is entirely fine with this.
>>>> And there is a use of the identifier in a monitored C file?
>>> 
>>> Yes.  traps-setup.c which definitely has not been added to an 
>>> exclusion
>>> list.
>>> 
>> 
>> Might look into it before the end of the week, if time allows. Is [1]
>> the right branch to look at?
>> 
>> [1]
>> https://gitlab.com/xen-project/hardware/xen-staging/-/commits/andrew/fred
> 
> Yes, although I am force pushing this with fixes as I find them.
> 
> In the latest run at the time of writing, I had one trivial R8.4
> violation to fix, and all other clean rules came up fine.  I expect the
> next run to be clean.
> 
> One thing that might be relevant, IIRC it's implementation defined
> behaviour what happens to constants which are wider than int to begin 
> with.
> 

See my other reply in this thread; the rule is concerned with the type 
of the constant present after preprocessing, which is defined in C99 
6.4.4.1.5 . As such, I'm not sure what you're hinting at regarding IDB 
here. Of course I might be wrong.

> ~Andrew

-- 
Nicola Vetrini, B.Sc.
Software Engineer
BUGSENG (https://bugseng.com)
LinkedIn: https://www.linkedin.com/in/nicola-vetrini-a42471253