From b56433cb782d1cc7e44fc46d2ce3917fa75d2236 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Mon, 27 May 2013 16:19:55 +0200 Subject: [PATCH] s390/pgtable: Fix check for pgste/storage key handling pte_present might return true on PAGE_TYPE_NONE, even if the invalid bit is on. Modify the existing check of the pgste functions to avoid crashes. [ Martin Schwidefsky: added ptep_modify_prot_[start|commit] bits ] Reported-by: Martin Schwidefky Signed-off-by: Christian Borntraeger CC: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 0f0de30e3e3f..ac01463038f1 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -646,7 +646,7 @@ static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste) unsigned long address, bits; unsigned char skey; - if (!pte_present(*ptep)) + if (pte_val(*ptep) & _PAGE_INVALID) return pgste; address = pte_val(*ptep) & PAGE_MASK; skey = page_get_storage_key(address); @@ -680,7 +680,7 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste) #ifdef CONFIG_PGSTE int young; - if (!pte_present(*ptep)) + if (pte_val(*ptep) & _PAGE_INVALID) return pgste; /* Get referenced bit from storage key */ young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK); @@ -706,7 +706,7 @@ static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry) unsigned long address; unsigned long okey, nkey; - if (!pte_present(entry)) + if (pte_val(entry) & _PAGE_INVALID) return; address = pte_val(entry) & PAGE_MASK; okey = nkey = page_get_storage_key(address); @@ -1098,6 +1098,9 @@ static inline pte_t ptep_modify_prot_start(struct mm_struct *mm, pte = *ptep; if (!mm_exclusive(mm)) __ptep_ipte(address, ptep); + + if (mm_has_pgste(mm)) + pgste = pgste_update_all(&pte, pgste); return pte; } @@ -1105,9 +1108,13 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long address, pte_t *ptep, pte_t pte) { + pgste_t pgste; + if (mm_has_pgste(mm)) { + pgste = *(pgste_t *)(ptep + PTRS_PER_PTE); + pgste_set_key(ptep, pgste, pte); pgste_set_pte(ptep, pte); - pgste_set_unlock(ptep, *(pgste_t *)(ptep + PTRS_PER_PTE)); + pgste_set_unlock(ptep, pgste); } else *ptep = pte; } -- GitLab