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Commit 29ecd660 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: avoid uninitialized variable warning 



This does not show up on all compiler versions, so it sneaked into the
first 4.3 pull request.  The fix is to mimic the logic of the "print
sptes" loop in the "fill array" loop.  Then leaf and root can be
both initialized unconditionally.

Note that "leaf" now points to the first unused element of the array,
not the last filled element.

Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4e33d1f0

arch/x86/kvm/mmu.c

+4 −3
Original line number Original line Diff line number Diff line
@@ -3309,13 +3309,14 @@ walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 




	walk_shadow_page_lockless_begin(vcpu);

	walk_shadow_page_lockless_begin(vcpu);





	for (shadow_walk_init(&iterator, vcpu, addr), root = iterator.level;

	for (shadow_walk_init(&iterator, vcpu, addr),

		 leaf = root = iterator.level;

	     shadow_walk_okay(&iterator);

	     shadow_walk_okay(&iterator);

	     __shadow_walk_next(&iterator, spte)) {

	     __shadow_walk_next(&iterator, spte)) {

		leaf = iterator.level;

		spte = mmu_spte_get_lockless(iterator.sptep);

		spte = mmu_spte_get_lockless(iterator.sptep);





		sptes[leaf - 1] = spte;

		sptes[leaf - 1] = spte;

		leaf--;





		if (!is_shadow_present_pte(spte))

		if (!is_shadow_present_pte(spte))

			break;

			break;
@@ -3329,7 +3330,7 @@ walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 
	if (reserved) {

	if (reserved) {

		pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",

		pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",

		       __func__, addr);

		       __func__, addr);

		while (root >= leaf) {

		while (root > leaf) {

			pr_err("------ spte 0x%llx level %d.\n",

			pr_err("------ spte 0x%llx level %d.\n",

			       sptes[root - 1], root);

			       sptes[root - 1], root);

			root--;

			root--;