Re: [PATCH v3] xen: address violations of MISRA C:2012 Rule 11.8.

[Simone Ballarin <simone.ballarin@bugseng.com>]

On 04/12/23 17:54, Jan Beulich wrote:
> On 04.12.2023 17:32, Simone Ballarin wrote:
>> From: Maria Celeste Cesario <maria.celeste.cesario@bugseng.com>
>>
>> Remove or amend casts to comply with Rule 11.8.
>>
>> Fix violations by adding missing const qualifier in cast.
>> Fix violations by removing unnecessary cast.
>> Change type of operands from char* to uintptr_t: uintptr_t is
>> the appropriate type for memory address operations.
>>
>> No functional changes.
>>
>> Signed-off-by: Maria Celeste Cesario  <maria.celeste.cesario@bugseng.com>
>> Signed-off-by: Simone Ballarin  <simone.ballarin@bugseng.com>
> 
> I consider it good practice to at least briefly say what the rule is
> about, so it is clear why certain changes need doing.
> 
>> --- a/xen/arch/arm/include/asm/atomic.h
>> +++ b/xen/arch/arm/include/asm/atomic.h
>> @@ -154,7 +154,7 @@ static always_inline void write_atomic_size(volatile void *p,
>>    */
>>   static inline int atomic_read(const atomic_t *v)
>>   {
>> -    return *(volatile int *)&v->counter;
>> +    return *(const volatile int *)&v->counter;
>>   }
> 
> What about PPC's identical code?

If the ARM part is accepted, I will include this change in an upcoming 
series for Rule 11.8 (which I'm working on), otherwise in v4.

> 
>> --- a/xen/arch/x86/include/asm/regs.h
>> +++ b/xen/arch/x86/include/asm/regs.h
>> @@ -6,7 +6,7 @@
>>   
>>   #define guest_mode(r)                                                         \
>>   ({                                                                            \
>> -    unsigned long diff = (char *)guest_cpu_user_regs() - (char *)(r);         \
>> +    unsigned long diff = (uintptr_t)guest_cpu_user_regs() - (uintptr_t)(r);   \
>>       /* Frame pointer must point into current CPU stack. */                    \
>>       ASSERT(diff < STACK_SIZE);                                                \
>>       /* If not a guest frame, it must be a hypervisor frame. */                \
> 
> This part
> Acked-by: Jan Beulich <jbeulich@suse.com>
> 
> Jan

-- 
Simone Ballarin, M.Sc.

Field Application Engineer, BUGSENG (https://bugseng.com)