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-rw-r--r--virt/kvm/arm/mmu.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 704e35f312a4..a2d63247d1bb 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -295,6 +295,13 @@ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
assert_spin_locked(&kvm->mmu_lock);
pgd = kvm->arch.pgd + stage2_pgd_index(addr);
do {
+ /*
+ * Make sure the page table is still active, as another thread
+ * could have possibly freed the page table, while we released
+ * the lock.
+ */
+ if (!READ_ONCE(kvm->arch.pgd))
+ break;
next = stage2_pgd_addr_end(addr, end);
if (!stage2_pgd_none(*pgd))
unmap_stage2_puds(kvm, pgd, addr, next);
@@ -1170,11 +1177,13 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
* large. Otherwise, we may see kernel panics with
* CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
* CONFIG_LOCKDEP. Additionally, holding the lock too long
- * will also starve other vCPUs.
+ * will also starve other vCPUs. We have to also make sure
+ * that the page tables are not freed while we released
+ * the lock.
*/
- if (need_resched() || spin_needbreak(&kvm->mmu_lock))
- cond_resched_lock(&kvm->mmu_lock);
-
+ cond_resched_lock(&kvm->mmu_lock);
+ if (!READ_ONCE(kvm->arch.pgd))
+ break;
next = stage2_pgd_addr_end(addr, end);
if (stage2_pgd_present(*pgd))
stage2_wp_puds(pgd, addr, next);