Re: [XEN PATCH][for-4.19] xen: replace occurrences of SAF-1-safe with asmlinkage attribute

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

On 2023-11-06 23:57, Julien Grall wrote:
> Hi Nicola,
> 
> On 03/11/2023 18:05, Nicola Vetrini wrote:
>> The comment-based justifications for MISRA C:2012 Rule 8.4 are 
>> replaced
>> by the asmlinkage pseudo-attribute, for the sake of uniformity.
>> The deviation with a comment based on the SAF framework is also
>> mentioned as a last resort.
> 
> I don't see any reason to keep SAF-1 after this patch. So can this be 
> removed?
> 

In documenting-violations.rst it's stated:
"Entries in the database shall never be removed, even if they are not 
used
anymore in the code (if a patch is removing or modifying the faulty 
line).
This is to make sure that numbers are not reused which could lead to 
conflicts
with old branches or misleading justifications."

that's why I kept SAF-1 in the safe.json file and added the remark about 
it
being a last resort. I am ok with that remark becoming not to use SAF-1 
in new code
at all (I probably didn't go back to check your reply when writing the 
patch).

>> 
>> Add missing 'xen/compiler.h' #include-s where needed.
>> 
>> The text in docs/misra/deviations.rst is modified to reflect this 
>> change.
>> 
>> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
>> ---
>>   docs/misra/deviations.rst   |  6 +++---
>>   xen/arch/arm/cpuerrata.c    |  7 +++----
>>   xen/arch/arm/setup.c        |  5 ++---
>>   xen/arch/arm/smpboot.c      |  3 +--
>>   xen/arch/arm/traps.c        | 21 +++++++--------------
>>   xen/arch/x86/boot/cmdline.c |  5 +++--
>>   xen/arch/x86/boot/reloc.c   |  7 ++++---
>>   xen/arch/x86/extable.c      |  3 +--
>>   xen/arch/x86/setup.c        |  3 +--
>>   xen/arch/x86/traps.c        | 27 +++++++++------------------
>>   xen/common/efi/boot.c       |  5 ++---
>>   11 files changed, 36 insertions(+), 56 deletions(-)
>> 
>> diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
>> index d468da2f5ce9..ed5d36c08647 100644
>> --- a/docs/misra/deviations.rst
>> +++ b/docs/misra/deviations.rst
>> @@ -134,9 +134,9 @@ Deviations related to MISRA C:2012 Rules:
>>        - Tagged as `safe` for ECLAIR.
>>        * - R8.4
>> -     - Functions and variables used only by asm modules are either 
>> marked with
>> -       the `asmlinkage` macro or with a SAF-1-safe textual deviation
>> -       (see safe.json).
> 
> I thought we agreed to a different wording [1]. So is this really based 
> on last version?
> 
>> +     - Functions and variables used only to interface with asm 
>> modules should
>> +       be marked with the `asmlinkage` macro. If that's not possible, 
>> consider
>> +       using the SAF-1-safe textual deviation (see safe.json).
> 
> See above. Actually, I am a bit surprised that SAF-1 is still mentioned 
> given that I have now requested multiple that it should be removed and 
> I haven't yet seen a reason to keep it.
> 
> Cheers,
> 
> [1] 
> https://lore.kernel.org/all/b914ac93-2499-4bfd-a60a-51a9f1c170ec@xen.org/

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)