Re: [XEN PATCH][for-4.19 v4 3/8] x86: add deviation comments for asm-only functions

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

On 24/10/2023 21:50, Stefano Stabellini wrote:
> On Tue, 24 Oct 2023, Nicola Vetrini wrote:
>> On 24/10/2023 10:14, Jan Beulich wrote:
>> > On 24.10.2023 10:01, Nicola Vetrini wrote:
>> > > On 24/10/2023 09:50, Jan Beulich wrote:
>> > > > On 23.10.2023 11:56, Nicola Vetrini wrote:
>> > > > > As stated in rules.rst, functions used only in asm code
>> > > > > are allowed to have no prior declaration visible when being
>> > > > > defined, hence these functions are deviated.
>> > > > > This also fixes violations of MISRA C:2012 Rule 8.4.
>> > > > >
>> > > > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
>> > > > > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
>> > > > > ---
>> > > > > Changes in v3:
>> > > > > - added SAF deviations for vmx counterparts to svm functions.
>> > > >
>> > > > Same comment regarding the R-b here as for patch 2.
>> > > >
>> > > > > --- a/xen/arch/x86/hvm/svm/intr.c
>> > > > > +++ b/xen/arch/x86/hvm/svm/intr.c
>> > > > > @@ -123,6 +123,7 @@ static void svm_enable_intr_window(struct vcpu *v,
>> > > > > struct hvm_intack intack)
>> > > > >          vmcb, general1_intercepts | GENERAL1_INTERCEPT_VINTR);
>> > > > >  }
>> > > > >
>> > > > > +/* SAF-1-safe */
>> > > > >  void svm_intr_assist(void)
>> > > > >  {
>> > > > >      struct vcpu *v = current;
>> > > >
>> > > > Linux has the concept of "asmlinkage" for functions interfacing C and
>> > > > assembly. Was it considered to use that - even if expanding to nothing
>> > > > for all present architectures - as a way to annotate affected
>> > > > definitions
>> > > > in place of the SAF-*-safe comments?
>> > >
>> > > It was proposed by Julien a while ago (I think it the thread on
>> > > deviations.rst) to define
>> > > a macro asmcall that expands to nothing, to mark all such functions.
>> > > Right now, it's not
>> > > strictly necessary (given that there are already some uses of SAF in
>> > > Stefano's for-4.19 branch.
>> >
>> > Can this then be revisited please before any such reaches staging?
>> >
>> > Jan
>> 
>> I'll let Stefano answer this one.
> 
> Yes it can. If Nicola sends new patches I'll make sure to remove the
> corresponding ones from for-4.19.
> 
> Nicola, you might want to send me privately the list of commits to take
> out from for-4.19.

Actually I checked: the involved SAF comments are already in staging, 
specifically all
were part of commit 5a415ef2b24d578d29479e38abda3d5285b9afed

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