s390/mm: fix pmd_huge() usage for kernel mapping
pmd_huge() will always return 0 on !HUGETLBFS, however we use that helper
function when walking the kernel page tables to decide if we have a
1MB page frame or not.
Since we create 1MB frames for the kernel 1:1 mapping independently of
HUGETLBFS this can lead to incorrect storage accesses since the code
can assume that we have a pointer to a page table instead of a pointer
to a 1MB frame.
Fix this by adding a pmd_large() primitive like other architectures have
it already and remove all references to HUGETLBFS/HUGETLBPAGE from the
code that walks kernel page tables.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index c22abf9..5b70393 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -79,7 +79,8 @@
*/
static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
{
- unsigned long address;
+ unsigned long end = start + size;
+ unsigned long address = start;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
@@ -87,7 +88,7 @@
pte_t pte;
int ret = -ENOMEM;
- for (address = start; address < start + size; address += PAGE_SIZE) {
+ while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
@@ -108,12 +109,11 @@
pm_dir = pmd_offset(pu_dir, address);
#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
- if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
- (address + HPAGE_SIZE <= start + size) &&
- (address >= HPAGE_SIZE)) {
+ if (MACHINE_HAS_EDAT1 && address && !(address & ~PMD_MASK) &&
+ (address + PMD_SIZE <= end)) {
pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
pmd_val(*pm_dir) = pte_val(pte);
- address += HPAGE_SIZE - PAGE_SIZE;
+ address += PMD_SIZE;
continue;
}
#endif
@@ -126,10 +126,11 @@
pt_dir = pte_offset_kernel(pm_dir, address);
*pt_dir = pte;
+ address += PAGE_SIZE;
}
ret = 0;
out:
- flush_tlb_kernel_range(start, start + size);
+ flush_tlb_kernel_range(start, end);
return ret;
}
@@ -139,7 +140,8 @@
*/
static void vmem_remove_range(unsigned long start, unsigned long size)
{
- unsigned long address;
+ unsigned long end = start + size;
+ unsigned long address = start;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
@@ -147,7 +149,7 @@
pte_t pte;
pte_val(pte) = _PAGE_TYPE_EMPTY;
- for (address = start; address < start + size; address += PAGE_SIZE) {
+ while (address < end) {
pg_dir = pgd_offset_k(address);
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir))
@@ -155,17 +157,16 @@
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir))
continue;
-
- if (pmd_huge(*pm_dir)) {
+ if (pmd_large(*pm_dir)) {
pmd_clear(pm_dir);
- address += HPAGE_SIZE - PAGE_SIZE;
+ address += PMD_SIZE;
continue;
}
-
pt_dir = pte_offset_kernel(pm_dir, address);
*pt_dir = pte;
+ address += PAGE_SIZE;
}
- flush_tlb_kernel_range(start, start + size);
+ flush_tlb_kernel_range(start, end);
}
/*