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[S390] fix pgste update logic

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The pgste_update_all / pgste_update_young and pgste_set_pte need to
check if the pte entry contains a valid page address before the storage
key can be accessed. In addition pgste_set_pte needs to set the access
key and fetch protection bit of the new pte entry, not the old entry.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2011-11-14 11:19:00 +01:00
parent 800252976b
commit 09b538833b
1 changed files with 9 additions and 3 deletions
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12
arch/s390/include/asm/pgtable.h
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@ -593,6 +593,8 @@ static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste)
unsigned long address, bits;
unsigned char skey;
if (!pte_present(*ptep))
return pgste;
address = pte_val(*ptep) & PAGE_MASK;
skey = page_get_storage_key(address);
bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
@ -625,6 +627,8 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
#ifdef CONFIG_PGSTE
int young;
if (!pte_present(*ptep))
return pgste;
young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
/* Transfer page referenced bit to pte software bit (host view) */
if (young || (pgste_val(pgste) & RCP_HR_BIT))
@ -638,13 +642,15 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
}
static inline void pgste_set_pte(pte_t *ptep, pgste_t pgste)
static inline void pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
{
#ifdef CONFIG_PGSTE
unsigned long address;
unsigned long okey, nkey;
address = pte_val(*ptep) & PAGE_MASK;
if (!pte_present(entry))
return;
address = pte_val(entry) & PAGE_MASK;
okey = nkey = page_get_storage_key(address);
nkey &= ~(_PAGE_ACC_BITS | _PAGE_FP_BIT);
/* Set page access key and fetch protection bit from pgste */
@ -712,7 +718,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
if (mm_has_pgste(mm)) {
pgste = pgste_get_lock(ptep);
pgste_set_pte(ptep, pgste);
pgste_set_pte(ptep, pgste, entry);
*ptep = entry;
pgste_set_unlock(ptep, pgste);
} else