Greg,
On Mon, Nov 15, 2021 at 6:10 PM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
From: Andreas Gruenbacher agruenba@redhat.com
commit 0c8eb2884a42d992c7726539328b7d3568f22143 upstream.
When switching from __get_user to fault_in_pages_readable, commit 9f9eae5ce717 broke kvm_use_magic_page: like __get_user, fault_in_pages_readable returns 0 on success.
I've not heard back from the maintainers about this patch so far, so it would probably be safer to leave it out of stable for now.
Thanks, Andreas
Fixes: 9f9eae5ce717 ("powerpc/kvm: Prefer fault_in_pages_readable function") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
arch/powerpc/kernel/kvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/powerpc/kernel/kvm.c +++ b/arch/powerpc/kernel/kvm.c @@ -669,7 +669,7 @@ static void __init kvm_use_magic_page(vo on_each_cpu(kvm_map_magic_page, &features, 1);
/* Quick self-test to see if the mapping works */
if (!fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) {
if (fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) { kvm_patching_worked = false; return; }