From 000d399625b4b302935508f2fc9ce93ff1bd1ba4 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 5 Mar 2013 02:43:17 +0000 Subject: 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 Signed-off-by: Christoffer Dall --- arch/arm/kvm/mmu.c | 44 ++++++++++++++++++++++++++------------------ 1 file changed, 26 insertions(+), 18 deletions(-) (limited to 'arch/arm/kvm') 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 @@ static void free_ptes(pmd_t *pmd, unsigned long addr) } } +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 - * only mappings in the kernel memory area, which is above PAGE_OFFSET. + * 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) { - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; 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); } -- cgit v1.1