s390/thp: respect page protection in pmd_none() and pmd_present()
Similar to pte_none() and pte_present(), the pmd functions should also
respect page protection of huge pages, especially PROT_NONE.
This patch also simplifies massage_pgprot_pmd() by adding new definitions
for huge page protection.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index dd647c9..2d3b7cb 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -506,12 +506,15 @@
static inline int pmd_present(pmd_t pmd)
{
- return (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) != 0UL;
+ unsigned long mask = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO;
+ return (pmd_val(pmd) & mask) == _HPAGE_TYPE_NONE ||
+ !(pmd_val(pmd) & _SEGMENT_ENTRY_INV);
}
static inline int pmd_none(pmd_t pmd)
{
- return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL;
+ return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) &&
+ !(pmd_val(pmd) & _SEGMENT_ENTRY_RO);
}
static inline int pmd_large(pmd_t pmd)
@@ -1223,6 +1226,11 @@
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+#define SEGMENT_NONE __pgprot(_HPAGE_TYPE_NONE)
+#define SEGMENT_RO __pgprot(_HPAGE_TYPE_RO)
+#define SEGMENT_RW __pgprot(_HPAGE_TYPE_RW)
+
#define __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
@@ -1242,16 +1250,15 @@
static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
{
- unsigned long pgprot_pmd = 0;
-
- if (pgprot_val(pgprot) & _PAGE_INVALID) {
- if (pgprot_val(pgprot) & _PAGE_SWT)
- pgprot_pmd |= _HPAGE_TYPE_NONE;
- pgprot_pmd |= _SEGMENT_ENTRY_INV;
- }
- if (pgprot_val(pgprot) & _PAGE_RO)
- pgprot_pmd |= _SEGMENT_ENTRY_RO;
- return pgprot_pmd;
+ /*
+ * pgprot is PAGE_NONE, PAGE_RO, or PAGE_RW (see __Pxxx / __Sxxx)
+ * Convert to segment table entry format.
+ */
+ if (pgprot_val(pgprot) == pgprot_val(PAGE_NONE))
+ return pgprot_val(SEGMENT_NONE);
+ if (pgprot_val(pgprot) == pgprot_val(PAGE_RO))
+ return pgprot_val(SEGMENT_RO);
+ return pgprot_val(SEGMENT_RW);
}
static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
@@ -1269,7 +1276,9 @@
static inline pmd_t pmd_mkwrite(pmd_t pmd)
{
- pmd_val(pmd) &= ~_SEGMENT_ENTRY_RO;
+ /* Do not clobber _HPAGE_TYPE_NONE pages! */
+ if (!(pmd_val(pmd) & _SEGMENT_ENTRY_INV))
+ pmd_val(pmd) &= ~_SEGMENT_ENTRY_RO;
return pmd;
}