KVM: x86: avoid uninitialized variable warning (29ecd660) · Commits · 戴 / test

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:

Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.c

+4 −3

Original line number	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);

		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_next(&iterator, spte)) {
		leaf = iterator.level;
		spte = mmu_spte_get_lockless(iterator.sptep);

		sptes[leaf - 1] = spte;
		leaf--;

		if (!is_shadow_present_pte(spte))
		break;
		@@ -3329,7 +3330,7 @@ walk_shadow_page_get_mmio_spte(struct kvm_vcpu vcpu, u64 addr, u64 sptep)
		if (reserved) {
		pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",
		__func__, addr);
		while (root >= leaf) {
		while (root > leaf) {
		pr_err("------ spte 0x%llx level %d.\n",
		sptes[root - 1], root);
		root--;

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