Re: [PATCH] KVM: Fix a warning in __kvm_gfn_to_hva_cache_init()

Gavin Shan
2020-05-04T23:20:40Z

On 5/5/20 5:05 AM, Peter Xu wrote:
> GCC 10.0.1 gives me this warning when building KVM:
>
> warning: ‘nr_pages_avail’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> 2442 | for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) {
>
> It should not happen, but silent it.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> virt/kvm/kvm_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 74bdb7bf3295..2da293885a67 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2425,7 +2425,7 @@ 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;
>
> /* Update ghc->generation before performing any error checks. */
> ghc->generation = slots->generation;
>