On Thu, Jan 09, 2020 at 02:58:55PM -0500, Barret Rhoden wrote: > If gfn_to_hva_many() fails, __kvm_gfn_to_hva_cache_init() will return an > error. Before it does, it might use nr_pages_avail, which my compiler > complained about: > > virt/kvm/kvm_main.c:2193:13: warning: 'nr_pages_avail' may be > used uninitialized in this function [-Wmaybe-uninitialized] > > start_gfn += nr_pages_avail; Ugh, this whole flow is funky. The change is correct, and is certainly the minimal change if we want to backport this to stable, but IMO it's putting lipstick on a pig. I'd rather fix the underlying issues and make the code more readable in the process. I'll send a patch. If we want to take this as a minimal fix, Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Signed-off-by: Barret Rhoden <brho@xxxxxxxxxx> > --- > virt/kvm/kvm_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index d9aced677ddd..f8249b153d33 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2172,7 +2172,7 @@ static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots, > gfn_t start_gfn = gpa >> PAGE_SHIFT; > gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT; > gfn_t nr_pages_needed = end_gfn - start_gfn + 1; > - gfn_t nr_pages_avail; > + gfn_t nr_pages_avail = 0; > int r = start_gfn <= end_gfn ? 0 : -EINVAL; > > ghc->gpa = gpa; > -- > 2.25.0.rc1.283.g88dfdc4193-goog >
