| Message ID | 51ECA4EC.3000408@asianux.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Maintainers: Please help check the patch whether OK or not, when you have time. Thanks. On 07/22/2013 11:20 AM, Chen Gang wrote: > 'len' is 'unsigned long' which is never less than zero. > > So need a related type cast for comparation. > > The related warning (when building ARM64 with allmodconfig): > > arch/arm64/kvm/../../../arch/arm/kvm/mmio.c:82:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] > > > Signed-off-by: Chen Gang <gang.chen@asianux.com> > --- > arch/arm/kvm/mmio.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c > index b8e06b7..626dfc8 100644 > --- a/arch/arm/kvm/mmio.c > +++ b/arch/arm/kvm/mmio.c > @@ -79,7 +79,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > } > > len = kvm_vcpu_dabt_get_as(vcpu); > - if (unlikely(len < 0)) > + if (unlikely((long)len < 0)) > return len; > > is_write = kvm_vcpu_dabt_iswrite(vcpu); >
On Mon, Jul 22, 2013 at 11:20:12AM +0800, Chen Gang wrote: > 'len' is 'unsigned long' which is never less than zero. > > So need a related type cast for comparation. > > The related warning (when building ARM64 with allmodconfig): > > arch/arm64/kvm/../../../arch/arm/kvm/mmio.c:82:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] > Hmmm, interesting, I don't get this error with my compiler. > > Signed-off-by: Chen Gang <gang.chen@asianux.com> > --- > arch/arm/kvm/mmio.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c > index b8e06b7..626dfc8 100644 > --- a/arch/arm/kvm/mmio.c > +++ b/arch/arm/kvm/mmio.c > @@ -79,7 +79,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > } > > len = kvm_vcpu_dabt_get_as(vcpu); > - if (unlikely(len < 0)) > + if (unlikely((long)len < 0)) > return len; > > is_write = kvm_vcpu_dabt_iswrite(vcpu); > -- > 1.7.7.6 I think the proper fix is to declare len as an int instead. I'll queue that instead. Thanks, -Christoffer
On 07/30/2013 11:45 AM, Christoffer Dall wrote: > On Mon, Jul 22, 2013 at 11:20:12AM +0800, Chen Gang wrote: >> 'len' is 'unsigned long' which is never less than zero. >> >> So need a related type cast for comparation. >> >> The related warning (when building ARM64 with allmodconfig): >> >> arch/arm64/kvm/../../../arch/arm/kvm/mmio.c:82:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] >> > > Hmmm, interesting, I don't get this error with my compiler. > >> >> Signed-off-by: Chen Gang <gang.chen@asianux.com> >> --- >> arch/arm/kvm/mmio.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c >> index b8e06b7..626dfc8 100644 >> --- a/arch/arm/kvm/mmio.c >> +++ b/arch/arm/kvm/mmio.c >> @@ -79,7 +79,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, >> } >> >> len = kvm_vcpu_dabt_get_as(vcpu); >> - if (unlikely(len < 0)) >> + if (unlikely((long)len < 0)) >> return len; >> >> is_write = kvm_vcpu_dabt_iswrite(vcpu); >> -- >> 1.7.7.6 > > I think the proper fix is to declare len as an int instead. I'll queue > that instead. > Yeah, it is fine to me (better than my original fix). Thanks.
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c index b8e06b7..626dfc8 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -79,7 +79,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, } len = kvm_vcpu_dabt_get_as(vcpu); - if (unlikely(len < 0)) + if (unlikely((long)len < 0)) return len; is_write = kvm_vcpu_dabt_iswrite(vcpu);
'len' is 'unsigned long' which is never less than zero. So need a related type cast for comparation. The related warning (when building ARM64 with allmodconfig): arch/arm64/kvm/../../../arch/arm/kvm/mmio.c:82:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] Signed-off-by: Chen Gang <gang.chen@asianux.com> --- arch/arm/kvm/mmio.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)