From 89db48d204669a5bcb87151b79dfe2b90356184c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 21 Jun 2021 15:47:20 +0100 Subject: [PATCH] ANDROID: KVM: arm64: Check for PTE valitity when checking for executable/cacheable Don't blindly assume that the PTE is valid when checking whether it describes an executable or cacheable mapping. This makes sure that we don't issue CMOs for invalid mappings. Suggested-by: Will Deacon Signed-off-by: Marc Zyngier Bug: 209580772 Change-Id: I5b271c91aa6ceb23f7b1e6a571e30d080866d5c9 Signed-off-by: Will Deacon --- arch/arm64/kvm/hyp/pgtable.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 9d2cf32c8b55..03bdf4f50826 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -692,12 +692,12 @@ static void stage2_put_pte(kvm_pte_t *ptep, struct kvm_s2_mmu *mmu, u64 addr, static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte) { u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR; - return memattr == KVM_S2_MEMATTR(pgt, NORMAL); + return kvm_pte_valid(pte) && memattr == KVM_S2_MEMATTR(pgt, NORMAL); } static bool stage2_pte_executable(kvm_pte_t pte) { - return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN); + return kvm_pte_valid(pte) && !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN); } static bool stage2_leaf_mapping_allowed(u64 addr, u64 end, u32 level, @@ -749,8 +749,7 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, /* Perform CMOs before installation of the guest stage-2 PTE */ if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new)) mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops), - granule); - + granule); if (mm_ops->icache_inval_pou && stage2_pte_executable(new)) mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule); @@ -1149,7 +1148,7 @@ static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; kvm_pte_t pte = *ptep; - if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte)) + if (!stage2_pte_cacheable(pgt, pte)) return 0; if (mm_ops->dcache_clean_inval_poc)