Re: [XEN PATCH v2] misra: address violation of MISRA C Rule 10.1

[Dmytro Prokopchuk1 <dmytro_prokopchuk1@xxxxxxxx>]

Hi All.

In this 2nd version I made changes according to the
https://patchew.org/Xen/d92cf08a64d8197a1d1a45f901e59183105d3da5.1752183472.git.dmytro._5Fprokopchuk1@xxxxxxxx/

There are 0 violations on the ARM64 as you can see in the report:
https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/people/dimaprkp4k/xen/ECLAIR_normal/fix_10.1_rule/ARM64/10650097988/PROJECT.ecd;/by_service.html#service&kind

Jan mentioned:
"As to the kind of change here - didn't we deviate applying unary minus
to unsigned types?"

Here is that deviation:
https://patchew.org/Xen/7c7b7a09e9d5ac1cc6f93fecacd8065fb6f25324.1745427770.git.victorm.lira@xxxxxxx/
As you can see from report
https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/people/dimaprkp4k/xen/ECLAIR_normal/deviate_10.1_rule/ARM64/10648749555/PROJECT.ecd;/by_service.html#service&kind
there are still 2 violations.
And they can be easily fixed.

So, Jan and Stefano,
which approach should we select?

BR, Dmytro.

On 7/11/25 14:43, Dmytro Prokopchuk1 wrote:
> Rule 10.1: Operands shall not be of an
> inappropriate essential type
>
> The following are non-compliant:
> - unary minus on unsigned type;
> - boolean used as a numeric value.
>
> Precede unary '-' operator with casting to signed type.
> Replace numeric constant '-1UL' with '~0UL'.
> Replace numeric constant '-1ULL' with '~0ULL'.
> Replace boolean with numeric value.
>
> Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@xxxxxxxx>
> ---
> Changes since v1:
> - changed patch subject prefix
> - multiplication replaced with cast
> Link to v1: 
> https://patchew.org/Xen/d92cf08a64d8197a1d1a45f901e59183105d3da5.1752183472.git.dmytro._5Fprokopchuk1@xxxxxxxx/
> ---
>   xen/arch/arm/gic-vgic.c               | 2 +-
>   xen/common/memory.c                   | 2 +-
>   xen/common/page_alloc.c               | 6 +++---
>   xen/common/time.c                     | 2 +-
>   xen/drivers/passthrough/arm/smmu-v3.c | 2 +-
>   xen/lib/strtol.c                      | 2 +-
>   xen/lib/strtoll.c                     | 2 +-
>   7 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/xen/arch/arm/gic-vgic.c b/xen/arch/arm/gic-vgic.c
> index ea48c5375a..a35f33c5f2 100644
> --- a/xen/arch/arm/gic-vgic.c
> +++ b/xen/arch/arm/gic-vgic.c
> @@ -17,7 +17,7 @@
>   #include <asm/vgic.h>
>
>   #define lr_all_full()                                           \
> -    (this_cpu(lr_mask) == (-1ULL >> (64 - gic_get_nr_lrs())))
> +    (this_cpu(lr_mask) == (~0ULL >> (64 - gic_get_nr_lrs())))
>
>   #undef GIC_DEBUG
>
> diff --git a/xen/common/memory.c b/xen/common/memory.c
> index 46620ed825..0a5b3fab04 100644
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -773,7 +773,7 @@ static long 
> memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg)
>
>                   nrspin_lock(&d->page_alloc_lock);
>                   drop_dom_ref = (dec_count &&
> -                                !domain_adjust_tot_pages(d, -dec_count));
> +                                !domain_adjust_tot_pages(d, 
> -(long)dec_count));
>                   nrspin_unlock(&d->page_alloc_lock);
>
>                   if ( drop_dom_ref )
> diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
> index 8f93a4c354..da8dddf934 100644
> --- a/xen/common/page_alloc.c
> +++ b/xen/common/page_alloc.c
> @@ -691,7 +691,7 @@ size_param("low_mem_virq_limit", opt_low_mem_virq);
>   /* Thresholds to control hysteresis. In pages */
>   /* When memory grows above this threshold, reset hysteresis.
>    * -1 initially to not reset until at least one virq issued. */
> -static unsigned long low_mem_virq_high      = -1UL;
> +static unsigned long low_mem_virq_high      = ~0UL;
>   /* Threshold at which we issue virq */
>   static unsigned long low_mem_virq_th        = 0;
>   /* Original threshold after all checks completed */
> @@ -710,7 +710,7 @@ static void __init setup_low_mem_virq(void)
>        * to ever trigger. */
>       if ( opt_low_mem_virq == 0 )
>       {
> -        low_mem_virq_th = -1UL;
> +        low_mem_virq_th = ~0UL;
>           return;
>       }
>
> @@ -778,7 +778,7 @@ static void check_low_mem_virq(void)
>           low_mem_virq_th_order++;
>           low_mem_virq_th = 1UL << low_mem_virq_th_order;
>           if ( low_mem_virq_th == low_mem_virq_orig )
> -            low_mem_virq_high = -1UL;
> +            low_mem_virq_high = ~0UL;
>           else
>               low_mem_virq_high = 1UL << (low_mem_virq_th_order + 2);
>       }
> diff --git a/xen/common/time.c b/xen/common/time.c
> index 92f7b72464..980dddee28 100644
> --- a/xen/common/time.c
> +++ b/xen/common/time.c
> @@ -84,7 +84,7 @@ struct tm gmtime(unsigned long t)
>       }
>       tbuf.tm_year = y - 1900;
>       tbuf.tm_yday = days;
> -    ip = (const unsigned short int *)__mon_lengths[__isleap(y)];
> +    ip = (const unsigned short int *)__mon_lengths[__isleap(y) ? 1 : 0];
>       for ( y = 0; days >= ip[y]; ++y )
>           days -= ip[y];
>       tbuf.tm_mon = y;
> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
> b/xen/drivers/passthrough/arm/smmu-v3.c
> index df16235057..4058b18f2c 100644
> --- a/xen/drivers/passthrough/arm/smmu-v3.c
> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
> @@ -315,7 +315,7 @@ static int queue_poll_cons(struct arm_smmu_queue *q, bool 
> sync, bool wfe)
>
>       while (queue_sync_cons_in(q),
>             (sync ? !queue_empty(&q->llq) : queue_full(&q->llq))) {
> -             if ((NOW() > timeout) > 0)
> +             if (NOW() > timeout)
>                       return -ETIMEDOUT;
>
>               if (wfe) {
> diff --git a/xen/lib/strtol.c b/xen/lib/strtol.c
> index 30dca779cf..c68d133657 100644
> --- a/xen/lib/strtol.c
> +++ b/xen/lib/strtol.c
> @@ -13,7 +13,7 @@
>   long simple_strtol(const char *cp, const char **endp, unsigned int base)
>   {
>       if ( *cp == '-' )
> -        return -simple_strtoul(cp + 1, endp, base);
> +        return -(long)simple_strtoul(cp + 1, endp, base);
>       return simple_strtoul(cp, endp, base);
>   }
>
> diff --git a/xen/lib/strtoll.c b/xen/lib/strtoll.c
> index 5d23fd80e8..6861d55929 100644
> --- a/xen/lib/strtoll.c
> +++ b/xen/lib/strtoll.c
> @@ -13,7 +13,7 @@
>   long long simple_strtoll(const char *cp, const char **endp, unsigned int 
> base)
>   {
>       if ( *cp == '-' )
> -        return -simple_strtoull(cp + 1, endp, base);
> +        return -(long long)simple_strtoull(cp + 1, endp, base);
>       return simple_strtoull(cp, endp, base);
>   }
>