Messages in this thread | | | Date | Tue, 11 Oct 2022 15:02:28 +0200 | Subject | Re: [kbuild] arch/x86/kvm/x86.c:4988 kvm_arch_tsc_set_attr() warn: check for integer overflow 'offset' | From | Paolo Bonzini <> |
| |
On 10/10/22 20:39, Sean Christopherson wrote: >> 828ca89628bfcb Oliver Upton 2021-09-16 @4988 tsc = kvm_scale_tsc(vcpu, rdtsc(), vcpu->arch.l1_tsc_scaling_ratio) + offset; >> >> Smatch hates obvious user triggerable integer overflows... No checking >> on offset. > > This is ok, and even necessary, e.g. if the host TSC > guest TSC.
(which in fact is the common case). Also this is unsigned which is fine according to the C standard, though I understand that static analyzers want to be stricter.
> Is there anything > we can do in KVM to help Smatch avoid false positives? Or do you/Smatch already > maintain a list of known false positives?
Seconded.
Paolo
| |