Compiling with THP enabled leads to the following warning:

arch/arm/kvm/mmu.c: In function ‘unmap_range’:
arch/arm/kvm/mmu.c:177:39: warning: ‘pte’ may be used uninitialized in this 
function [-Wmaybe-uninitialized]
   if (kvm_pmd_huge(*pmd) || page_empty(pte)) {
                                        ^
Code inspection reveals that these two cases are mutually exclusive,
so GCC is a bit overzealous here. But silence it anyway by setting
pte to NULL if kvm_pmd_huge(*pmd) is true.

Signed-off-by: Marc Zyngier <[email protected]>
---
 arch/arm/kvm/mmu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index ea21b6a..3020221 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -169,12 +169,14 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
                        pte = pte_offset_kernel(pmd, addr);
                        clear_pte_entry(kvm, pte, addr);
                        next = addr + PAGE_SIZE;
+               } else {
+                       pte = NULL;
                }
 
                /*
                 * If the pmd entry is to be cleared, walk back up the ladder
                 */
-               if (kvm_pmd_huge(*pmd) || page_empty(pte)) {
+               if (kvm_pmd_huge(*pmd) || (pte && page_empty(pte))) {
                        clear_pmd_entry(kvm, pmd, addr);
                        next = pmd_addr_end(addr, end);
                        if (page_empty(pmd) && !page_empty(pud)) {
-- 
1.8.3.4

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