Re: [PATCH] KVM: arm64: Remove spurious semicolon in reg_to_encoding()

[Marc Zyngier <maz@kernel.org>]

On 2021-01-05 13:54, Alexandru Elisei wrote:
> Hi Marc,
> 
> On 12/31/20 3:09 PM, Marc Zyngier wrote:
>> Although not a problem right now, it flared up while working
>> on some other aspects of the code-base. Remove the useless
>> semicolon.
>> 
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>>  arch/arm64/kvm/sys_regs.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
>> index d46e7f706cb0..42ccc27fb684 100644
>> --- a/arch/arm64/kvm/sys_regs.c
>> +++ b/arch/arm64/kvm/sys_regs.c
>> @@ -923,7 +923,7 @@ static bool access_pmuserenr(struct kvm_vcpu 
>> *vcpu, struct sys_reg_params *p,
>> 
>>  #define reg_to_encoding(x)						\
>>  	sys_reg((u32)(x)->Op0, (u32)(x)->Op1,				\
>> -		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2);
>> +		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
> 
> Macro's shouldn't really end with a semicolon, otherwise code might 
> break
> unexpectedly:
> 
> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
> 
> I skimmed over the code and the macro is used like a function. Do you 
> think it's
> worth turning it into a function to gain type checking for the
> argument (which is
> expected to be sys_reg_desc) and for the return value?

Not quite.

This macro takes indifferently a sys_reg_desc or a sys_reg_params,
making it impossible to turn into a function. Is it disgusting and
makes you want to pull your eyes out? Yes.

The whole params/desc duality dates back to the early 32bit code,
and I blame Rusty Russell for it. Just saying... ;-)

That's one of things I always wanted to refactor...

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...
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