Re: [RFC PATCH 4/4] xen: Justify linker script defined symbols in include/xen/kernel.h

[Luca Fancellu <Luca.Fancellu@xxxxxxx>]

> On 8 Nov 2022, at 11:32, Julien Grall <julien@xxxxxxx> wrote:
> 
> Hi Luca,
> 
> On 08/11/2022 11:00, Luca Fancellu wrote:
>>> On 7 Nov 2022, at 19:06, Julien Grall <julien@xxxxxxx> wrote:
>>> 
>>> 
>>> 
>>> On 07/11/2022 12:56, Jan Beulich wrote:
>>>> On 07.11.2022 12:53, Luca Fancellu wrote:
>>>>>> On 7 Nov 2022, at 11:49, Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>>>>> On 07.11.2022 11:47, Luca Fancellu wrote:
>>>>>>> --- a/xen/include/xen/kernel.h
>>>>>>> +++ b/xen/include/xen/kernel.h
>>>>>>> @@ -65,24 +65,28 @@
>>>>>>>         1;                                      \
>>>>>>> })
>>>>>>> 
>>>>>>> +/* SAF-0-safe R8.6 linker script defined symbols */
>>>>>>> extern char _start[], _end[], start[];
>>>>>>> #define is_kernel(p) ({                         \
>>>>>>>     char *__p = (char *)(unsigned long)(p);     \
>>>>>>>     (__p >= _start) && (__p < _end);            \
>>>>>>> })
>>>>>>> 
>>>>>>> +/* SAF-0-safe R8.6 linker script defined symbols */
>>>>>>> extern char _stext[], _etext[];
>>>>>>> #define is_kernel_text(p) ({                    \
>>>>>>>     char *__p = (char *)(unsigned long)(p);     \
>>>>>>>     (__p >= _stext) && (__p < _etext);          \
>>>>>>> })
>>>>>>> 
>>>>>>> +/* SAF-0-safe R8.6 linker script defined symbols */
>>>>>>> extern const char _srodata[], _erodata[];
>>>>>>> #define is_kernel_rodata(p) ({                  \
>>>>>>>     const char *__p = (const char *)(unsigned long)(p);     \
>>>>>>>     (__p >= _srodata) && (__p < _erodata);      \
>>>>>>> })
>>>>>>> 
>>>>>>> +/* SAF-0-safe R8.6 linker script defined symbols */
>>>>>>> extern char _sinittext[], _einittext[];
>>>>>>> #define is_kernel_inittext(p) ({                \
>>>>>>>     char *__p = (char *)(unsigned long)(p);     \
>>>>>> 
>>>>>> Why the "R8.6" everywhere here? Didn't we agree that the in-code
>>>>>> comments should be tool-agnostic?
>>>>> 
>>>>> The R8.6 is not tool specific, it is to give the quick hint that we are 
>>>>> deviating
>>>>> from MISRA Rule 8.6.
>>>> Well, yes, "tool" was wrong for me to write. Imo references to a specific
>>>> spec should equally be avoided in in-code comments, as other specs may
>>>> turn up.
>>> 
>>> +1. The comment duplication is not great and sometimes even a short 
>>> explanation it may not fit in 80 characters (AFAICT the justification 
>>> should be a one line comment).
>>> 
>> Ok we can remove the R8.6 from the comments, is the remaining part ok?
> 
> I am afraid no. The comment should only be /* SAF-0-safe */.

Ok I will go for that in the next serie

> 
> Cheers,
> 
> -- 
> Julien Grall