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Commit 09b53883 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] fix pgste update logic 



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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 80025297

arch/s390/include/asm/pgtable.h

+9 −3
Original line number Diff line number Diff line
@@ -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