Re: [XEN PATCH 07/11] xen/page_alloc: address violations of MISRA C Rule 20.7

From: Nicola Vetrini <nicola.vetrini@bugseng.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: sstabellini@kernel.org, michal.orzel@amd.com,
	xenia.ragiadakou@amd.com, ayan.kumar.halder@amd.com,
	consulting@bugseng.com, andrew.cooper3@citrix.com,
	roger.pau@citrix.com, bertrand.marquis@arm.com, julien@xen.org,
	George Dunlap <george.dunlap@citrix.com>,
	xen-devel@lists.xenproject.org
Subject: Re: [XEN PATCH 07/11] xen/page_alloc: address violations of MISRA C Rule 20.7
Date: Tue, 26 Mar 2024 16:57:29 +0100	[thread overview]
Message-ID: <dee83e2e49e004b9b7ae7f66cade0525@bugseng.com> (raw)
In-Reply-To: <f8cfa921-5586-4fe0-a18b-a34255a37731@suse.com>

On 2024-03-26 16:35, Jan Beulich wrote:
> On 26.03.2024 16:27, Nicola Vetrini wrote:
>> On 2024-03-25 10:27, Jan Beulich wrote:
>>> On 22.03.2024 17:01, Nicola Vetrini wrote:
>>>> --- a/xen/common/page_alloc.c
>>>> +++ b/xen/common/page_alloc.c
>>>> @@ -150,7 +150,7 @@
>>>>  #include <asm/paging.h>
>>>>  #else
>>>>  #define p2m_pod_offline_or_broken_hit(pg) 0
>>> 
>>> Seeing this in context: Does Misra also have a rule demanding
>>> evaluation
>>> of macro arguments?
>> 
>> No such rule. There is one for unused function parameters, though.
> 
> Interesting. Are there no concerns regarding side effects not taking
> place, as one might expect when looking just at the call site?
> 

I don't know. Either it was never discussed or it never made it to the 
final revisions, I guess.

>>>> -#define p2m_pod_offline_or_broken_replace(pg) BUG_ON(pg != NULL)
>>>> +#define p2m_pod_offline_or_broken_replace(pg) BUG_ON((pg) != NULL)
>>> 
>>> Or easier
>>> 
>>> #define p2m_pod_offline_or_broken_replace(pg) BUG_ON(pg)
>>> 
>>> ?
>>> 
>> 
>> Good point. I'll modify it.
> 
> I can do that as well while committing. With that adjustment
> Acked-by: Jan Beulich <jbeulich@suse.com>
> 
> Jan

Thanks

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