From d8073dc6bc04a061660b31e49a990478a73f1883 Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Fri, 7 Jun 2024 14:19:48 +0200 Subject: s390/mm: Allow large pages only for aligned physical addresses Do not allow creation of large pages against physical addresses, which itself are not aligned on the correct boundary. Failure to do so might lead to referencing wrong memory as result of the way DAT works. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik --- arch/s390/boot/vmem.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c index 96d48b7112d4..1f7dbb4b66b7 100644 --- a/arch/s390/boot/vmem.c +++ b/arch/s390/boot/vmem.c @@ -267,15 +267,21 @@ static bool large_allowed(enum populate_mode mode) static bool can_large_pud(pud_t *pu_dir, unsigned long addr, unsigned long end, enum populate_mode mode) { + unsigned long size = end - addr; + return machine.has_edat2 && large_allowed(mode) && - IS_ALIGNED(addr, PUD_SIZE) && (end - addr) >= PUD_SIZE; + IS_ALIGNED(addr, PUD_SIZE) && (size >= PUD_SIZE) && + IS_ALIGNED(_pa(addr, size, mode), PUD_SIZE); } static bool can_large_pmd(pmd_t *pm_dir, unsigned long addr, unsigned long end, enum populate_mode mode) { + unsigned long size = end - addr; + return machine.has_edat1 && large_allowed(mode) && - IS_ALIGNED(addr, PMD_SIZE) && (end - addr) >= PMD_SIZE; + IS_ALIGNED(addr, PMD_SIZE) && (size >= PMD_SIZE) && + IS_ALIGNED(_pa(addr, size, mode), PMD_SIZE); } static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long end, -- cgit v1.2.3