ARM: KVM: sanitize freeing of HYP page tables
Instead of trying to free everything from PAGE_OFFSET to the
top of memory, use the virt_addr_valid macro to check the
upper limit.
Also do the same for the vmalloc region where the IO mappings
are allocated.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 0bf2c85..2f12e40 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -85,34 +85,42 @@
}
}
-/**
- * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables
- *
- * Assumes this is a page table used strictly in Hyp-mode and therefore contains
- * only mappings in the kernel memory area, which is above PAGE_OFFSET.
- */
-void free_hyp_pmds(void)
+static void free_hyp_pgd_entry(unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
+ unsigned long hyp_addr = KERN_TO_HYP(addr);
+
+ pgd = hyp_pgd + pgd_index(hyp_addr);
+ pud = pud_offset(pgd, hyp_addr);
+
+ if (pud_none(*pud))
+ return;
+ BUG_ON(pud_bad(*pud));
+
+ pmd = pmd_offset(pud, hyp_addr);
+ free_ptes(pmd, addr);
+ pmd_free(NULL, pmd);
+ pud_clear(pud);
+}
+
+/**
+ * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables
+ *
+ * Assumes this is a page table used strictly in Hyp-mode and therefore contains
+ * either mappings in the kernel memory area (above PAGE_OFFSET), or
+ * device mappings in the vmalloc range (from VMALLOC_START to VMALLOC_END).
+ */
+void free_hyp_pmds(void)
+{
unsigned long addr;
mutex_lock(&kvm_hyp_pgd_mutex);
- for (addr = PAGE_OFFSET; addr != 0; addr += PGDIR_SIZE) {
- unsigned long hyp_addr = KERN_TO_HYP(addr);
- pgd = hyp_pgd + pgd_index(hyp_addr);
- pud = pud_offset(pgd, hyp_addr);
-
- if (pud_none(*pud))
- continue;
- BUG_ON(pud_bad(*pud));
-
- pmd = pmd_offset(pud, hyp_addr);
- free_ptes(pmd, addr);
- pmd_free(NULL, pmd);
- pud_clear(pud);
- }
+ for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
+ free_hyp_pgd_entry(addr);
+ for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
+ free_hyp_pgd_entry(addr);
mutex_unlock(&kvm_hyp_pgd_mutex);
}