Re: [PATCH 1/2] KVM: s390: rename PROT_NONE to PROT_TYPE_DUMMY

[Liam R. Howlett]

* Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> [250515 16:15]:
> The enum type prot_type declared in arch/s390/kvm/gaccess.c declares an
> unfortunate identifier within it - PROT_NONE.
> 
> This clashes with the protection bit define from the uapi for mmap()
> declared in include/uapi/asm-generic/mman-common.h, which is indeed what
> those casually reading this code would assume this to refer to.
> 
> This means that any changes which subsequently alter headers in any way
> which results in the uapi header being imported here will cause build
> errors.
> 
> Resolve the issue by renaming PROT_NONE to PROT_TYPE_DUMMY.
> 
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
> Suggested-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@xxxxxxxx>
> Fixes: b3cefd6bf16e ("KVM: s390: Pass initialized arg even if unused")
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202505140943.IgHDa9s7-lkp@xxxxxxxxx/
> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
> Acked-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@xxxxxxxx>
> Acked-by: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

Acked-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>

> ---
>  arch/s390/kvm/gaccess.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
> index f6fded15633a..4e5654ad1604 100644
> --- a/arch/s390/kvm/gaccess.c
> +++ b/arch/s390/kvm/gaccess.c
> @@ -318,7 +318,7 @@ enum prot_type {
>  	PROT_TYPE_DAT  = 3,
>  	PROT_TYPE_IEP  = 4,
>  	/* Dummy value for passing an initialized value when code != PGM_PROTECTION */
> -	PROT_NONE,
> +	PROT_TYPE_DUMMY,
>  };
>  
>  static int trans_exc_ending(struct kvm_vcpu *vcpu, int code, unsigned long gva, u8 ar,
> @@ -334,7 +334,7 @@ static int trans_exc_ending(struct kvm_vcpu *vcpu, int code, unsigned long gva,
>  	switch (code) {
>  	case PGM_PROTECTION:
>  		switch (prot) {
> -		case PROT_NONE:
> +		case PROT_TYPE_DUMMY:
>  			/* We should never get here, acts like termination */
>  			WARN_ON_ONCE(1);
>  			break;
> @@ -804,7 +804,7 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
>  			gpa = kvm_s390_real_to_abs(vcpu, ga);
>  			if (!kvm_is_gpa_in_memslot(vcpu->kvm, gpa)) {
>  				rc = PGM_ADDRESSING;
> -				prot = PROT_NONE;
> +				prot = PROT_TYPE_DUMMY;
>  			}
>  		}
>  		if (rc)
> @@ -962,7 +962,7 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
>  		if (rc == PGM_PROTECTION)
>  			prot = PROT_TYPE_KEYC;
>  		else
> -			prot = PROT_NONE;
> +			prot = PROT_TYPE_DUMMY;
>  		rc = trans_exc_ending(vcpu, rc, ga, ar, mode, prot, terminate);
>  	}
>  out_unlock:
> -- 
> 2.49.0
>