On Tue, Jan 10, 2023 at 10:16 AM Tom Lendacky <thomas.lendacky@xxxxxxx> wrote: > > On 1/10/23 10:44, Peter Gonda wrote: > >>> > >>> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > >>> index 273cba809328..9451de72f917 100644 > >>> --- a/arch/x86/kvm/svm/sev.c > >>> +++ b/arch/x86/kvm/svm/sev.c > >>> @@ -1294,7 +1294,7 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) > >>> > >>> /* Check if we are crossing the page boundary */ > >>> offset = params.guest_uaddr & (PAGE_SIZE - 1); > >>> - if ((params.guest_len + offset > PAGE_SIZE)) > >>> + if (params.guest_len > PAGE_SIZE || (params.guest_len + offset > PAGE_SIZE)) > >> > >> I see the original if statement had double parentheses, which looks > >> strange. Should this if (and the one below) be: > >> > >> if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE) > > > > Isn't the order of operations here: '+' and then '>'. So is the patch > > correct and matches the old conditional? I am fine adding additional > > But what was the purpose of them in the old conditional? They weren't > necessary. > > But, yes, that order of operations is correct and those are both before > '||'. So the extra parentheses around the second condition check are still > strange then, right? > > Given that, then: > > if (params.guest_len > PAGE_SIZE || params.guest_len + offset > PAGE_SIZE) > > > () for clarity though. > > I do like the look and clarity of the parentheses around the addition. Sounds good to me. I'll update the V2 in a couple days to wait for any other comments. > > Thanks, > Tom
