From: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
commit b0e98aa9c411585eb586b2fa98873c936735008e upstream.
pmd/pud_deref() assume that they will never operate on large pmd/pud
entries, and therefore only use the non-large _xxx_ENTRY_ORIGIN mask.
With commit 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable()
to handle vmemmap"), that assumption is no longer true, at least for
pmd_deref().
In theory, we could end up with wrong addresses because some of the
non-address bits of a large entry would not be masked out.
In practice, this does not (yet) show any impact, because vmemmap_free()
is currently never used for s390.
Fix pmd/pud_deref() to check for the entry type and use the
_xxx_ENTRY_ORIGIN_LARGE mask for large entries.
While at it, also move pmd/pud_pfn() around, in order to avoid code
duplication, because they do the same thing.
Fixes: 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable() to handle vmemmap")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.9
Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Reviewed-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/pgtable.h | 52 +++++++++++++++++++++++-----------------
1 file changed, 30 insertions(+), 22 deletions(-)
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -691,16 +691,6 @@ static inline int pud_large(pud_t pud)
return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
}
-static inline unsigned long pud_pfn(pud_t pud)
-{
- unsigned long origin_mask;
-
- origin_mask = _REGION_ENTRY_ORIGIN;
- if (pud_large(pud))
- origin_mask = _REGION3_ENTRY_ORIGIN_LARGE;
- return (pud_val(pud) & origin_mask) >> PAGE_SHIFT;
-}
-
#define pmd_leaf pmd_large
static inline int pmd_large(pmd_t pmd)
{
@@ -746,16 +736,6 @@ static inline int pmd_none(pmd_t pmd)
return pmd_val(pmd) == _SEGMENT_ENTRY_EMPTY;
}
-static inline unsigned long pmd_pfn(pmd_t pmd)
-{
- unsigned long origin_mask;
-
- origin_mask = _SEGMENT_ENTRY_ORIGIN;
- if (pmd_large(pmd))
- origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
- return (pmd_val(pmd) & origin_mask) >> PAGE_SHIFT;
-}
-
#define pmd_write pmd_write
static inline int pmd_write(pmd_t pmd)
{
@@ -1230,11 +1210,39 @@ static inline pte_t mk_pte(struct page *
#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
-#define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
-#define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
#define p4d_deref(pud) (p4d_val(pud) & _REGION_ENTRY_ORIGIN)
#define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN)
+static inline unsigned long pmd_deref(pmd_t pmd)
+{
+ unsigned long origin_mask;
+
+ origin_mask = _SEGMENT_ENTRY_ORIGIN;
+ if (pmd_large(pmd))
+ origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
+ return pmd_val(pmd) & origin_mask;
+}
+
+static inline unsigned long pmd_pfn(pmd_t pmd)
+{
+ return pmd_deref(pmd) >> PAGE_SHIFT;
+}
+
+static inline unsigned long pud_deref(pud_t pud)
+{
+ unsigned long origin_mask;
+
+ origin_mask = _REGION_ENTRY_ORIGIN;
+ if (pud_large(pud))
+ origin_mask = _REGION3_ENTRY_ORIGIN_LARGE;
+ return pud_val(pud) & origin_mask;
+}
+
+static inline unsigned long pud_pfn(pud_t pud)
+{
+ return pud_deref(pud) >> PAGE_SHIFT;
+}
+
/*
* The pgd_offset function *always* adds the index for the top-level
* region/segment table. This is done to get a sequence like the
