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authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-10-01 12:58:34 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-10-09 14:16:56 +0200
commit378b1e7a80a59325ca1036e892462db728126f84 (patch)
tree6d25959ac7401eee48f76441ca42c2759aef15b4 /arch/s390
parent521b3d790c16fad9d83c72d610c1e416ad3f7ae3 (diff)
downloadlinux-378b1e7a80a59325ca1036e892462db728126f84.tar.bz2
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/pgtable.h9
-rw-r--r--arch/s390/mm/pageattr.c2
-rw-r--r--arch/s390/mm/vmem.c29
3 files changed, 25 insertions, 15 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 979fe3dc0788..75b91bb772bd 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -507,6 +507,15 @@ static inline int pmd_none(pmd_t pmd)
return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL;
}
+static inline int pmd_large(pmd_t pmd)
+{
+#ifdef CONFIG_64BIT
+ return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
+#else
+ return 0;
+#endif
+}
+
static inline int pmd_bad(pmd_t pmd)
{
unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index b36537a5f43e..0f33bab3e984 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -21,7 +21,7 @@ static void change_page_attr(unsigned long addr, int numpages,
pgdp = pgd_offset(&init_mm, addr);
pudp = pud_offset(pgdp, addr);
pmdp = pmd_offset(pudp, addr);
- if (pmd_huge(*pmdp)) {
+ if (pmd_large(*pmdp)) {
WARN_ON_ONCE(1);
continue;
}
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index c22abf900c9e..5b70393911bd 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -79,7 +79,8 @@ static pte_t __ref *vmem_pte_alloc(unsigned long address)
*/
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 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
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 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
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 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
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 @@ out:
*/
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 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
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 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
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);
}
/*