From b56433cb782d1cc7e44fc46d2ce3917fa75d2236 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
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 <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
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 0f0de30e3e3fcc..ac01463038f1e9 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;
}
--
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