Re: [XEN PATCH v3 3/3] xen: fix violations of MISRA C:2012 Rule 3.1

[Luca Fancellu <Luca.Fancellu@xxxxxxx>]

> On 29 Jun 2023, at 11:06, Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx> wrote:
> 
> In the files modified by this patch there are a few occurrences of nested '//'
> character sequences inside C-style comment blocks, which violate Rule 3.1.
> The patch aims to resolve those by removing the nested comments.
> 
> In the file 'xen/common/xmalloc_tlsf.c' the comment has been replaces by

Typo: s/replaces/replaced/

> an ASSERT, to ensure that the invariant in the comment is enforced.
> 
> In the file 'xen/include/xen/atomic.h' the nested comment has been removed,
> since the code sample is already explained by the preceding comment.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>

Same as patch 2, missing “---"

> Changes:
> - Resending the patch with the right maintainers in CC.
> Changes in V2:
> - Split the patch into a series and reworked the fix;
> - Apply the fix to the arm32 `flushtlb.h' file, for consistency.
> Changes in V3:
> - Replaced commmented-out 'if' with an ASSERT( *fl >= 0 ).
> ---
> xen/common/xmalloc_tlsf.c | 4 +---
> xen/include/xen/atomic.h  | 2 +-
> 2 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/xen/common/xmalloc_tlsf.c b/xen/common/xmalloc_tlsf.c
> index 75bdf18c4e..95affcc571 100644
> --- a/xen/common/xmalloc_tlsf.c
> +++ b/xen/common/xmalloc_tlsf.c
> @@ -140,9 +140,7 @@ static inline void MAPPING_SEARCH(unsigned long *r, int 
> *fl, int *sl)
>         *fl = flsl(*r) - 1;
>         *sl = (*r >> (*fl - MAX_LOG2_SLI)) - MAX_SLI;
>         *fl -= FLI_OFFSET;
> -        /*if ((*fl -= FLI_OFFSET) < 0) // FL will be always >0!
> -         *fl = *sl = 0;
> -         */
> +        ASSERT( *fl >= 0 );

I’ve checked the codebase for usage of ASSERT, but I’ve not seen use of it with 
spaces
before and after the condition (like our if conditions) so I think they can be 
dropped.

>         *r &= ~t;
>     }
> }
> diff --git a/xen/include/xen/atomic.h b/xen/include/xen/atomic.h
> index 529213ebbb..fa750a18ae 100644
> --- a/xen/include/xen/atomic.h
> +++ b/xen/include/xen/atomic.h
> @@ -78,7 +78,7 @@ static inline void _atomic_set(atomic_t *v, int i);
>  *      int old = atomic_read(&v);
>  *      int new = old + 1;
>  *      if ( likely(old == atomic_cmpxchg(&v, old, new)) )
> - *          break; // success!
> + *          break;
>  *  }
>  */
> static inline int atomic_cmpxchg(atomic_t *v, int old, int new);
> -- 
> 2.34.1
> 
> 

With the comments addressed:
Reviewed-by: Luca Fancellu <luca.fancellu@xxxxxxx>