| Message ID | 20230307135233.54684-1-wei.w.wang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: allow KVM_BUG/KVM_BUG_ON to handle 64-bit cond | expand |
On Tue, Mar 7, 2023 at 5:52 AM Wei Wang <wei.w.wang@intel.com> wrote: > > Current KVM_BUG and KVM_BUG_ON assume that 'cond' passed from callers is > 32-bit as it casts 'cond' to the type of int. This will be wrong if 'cond' > provided by a caller is 64-bit, e.g. an error code of 0xc0000d0300000000 > will be converted to 0, which is not expected. > > Improves the implementation by using bool in KVM_BUG and KVM_BUG_ON. > 'bool' is preferred to 'int' as __ret is essentially used as a boolean > and coding-stytle.rst documents that use of bool is encouraged to improve > readability and is often a better option than 'int' for storing boolean > values. > > Fixes: 0b8f11737cff ("KVM: Add infrastructure and macro to mark VM as bugged") > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > --- Reviewed-by: Mingwei Zhang <mizhang@google.com>
On Tue, Mar 07, 2023, Wei Wang wrote: > Current KVM_BUG and KVM_BUG_ON assume that 'cond' passed from callers is > 32-bit as it casts 'cond' to the type of int. You're very generous, I would have led with "Fix a badly done copy+paste ..." ;-) > Fixes: 0b8f11737cff ("KVM: Add infrastructure and macro to mark VM as bugged") > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > --- Reviewed-by: Sean Christopherson <seanjc@google.com>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f06635b24bd0..0221a48b3e3d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -881,7 +881,7 @@ static inline void kvm_vm_bugged(struct kvm *kvm) #define KVM_BUG(cond, kvm, fmt...) \ ({ \ - int __ret = (cond); \ + bool __ret = !!(cond); \ \ if (WARN_ONCE(__ret && !(kvm)->vm_bugged, fmt)) \ kvm_vm_bugged(kvm); \ @@ -890,7 +890,7 @@ static inline void kvm_vm_bugged(struct kvm *kvm) #define KVM_BUG_ON(cond, kvm) \ ({ \ - int __ret = (cond); \ + bool __ret = !!(cond); \ \ if (WARN_ON_ONCE(__ret && !(kvm)->vm_bugged)) \ kvm_vm_bugged(kvm); \
Current KVM_BUG and KVM_BUG_ON assume that 'cond' passed from callers is 32-bit as it casts 'cond' to the type of int. This will be wrong if 'cond' provided by a caller is 64-bit, e.g. an error code of 0xc0000d0300000000 will be converted to 0, which is not expected. Improves the implementation by using bool in KVM_BUG and KVM_BUG_ON. 'bool' is preferred to 'int' as __ret is essentially used as a boolean and coding-stytle.rst documents that use of bool is encouraged to improve readability and is often a better option than 'int' for storing boolean values. Fixes: 0b8f11737cff ("KVM: Add infrastructure and macro to mark VM as bugged") Signed-off-by: Wei Wang <wei.w.wang@intel.com> --- include/linux/kvm_host.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)