summaryrefslogtreecommitdiff
path: root/arch/s390/include/asm/pgtable.h
diff options
context:
space:
mode:
authorChristian Borntraeger <borntraeger@de.ibm.com>2008-10-28 13:10:15 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-10-28 13:12:03 +0300
commit250cf776f74b5932a1977d0489cae9206e2351dd (patch)
tree71bb6778e65e8efbdd0cac09a64e4e1194b98c3f /arch/s390/include/asm/pgtable.h
parent2c78091405d6f54748b1fac78c45f2a799e3073a (diff)
downloadlinux-250cf776f74b5932a1977d0489cae9206e2351dd.tar.xz
[S390] pgtables: Fix race in enable_sie vs. page table ops
The current enable_sie code sets the mm->context.pgstes bit to tell dup_mm that the new mm should have extended page tables. This bit is also used by the s390 specific page table primitives to decide about the page table layout - which means context.pgstes has two meanings. This can cause any kind of bugs. For example - e.g. shrink_zone can call ptep_clear_flush_young while enable_sie is running. ptep_clear_flush_young will test for context.pgstes. Since enable_sie changed that value of the old struct mm without changing the page table layout ptep_clear_flush_young will do the wrong thing. The solution is to split pgstes into two bits - one for the allocation - one for the current state Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
-rw-r--r--arch/s390/include/asm/pgtable.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 1a928f84afd6..7fc76133b3e4 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -679,7 +679,7 @@ static inline void pmd_clear(pmd_t *pmd)
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
- if (mm->context.pgstes)
+ if (mm->context.has_pgste)
ptep_rcp_copy(ptep);
pte_val(*ptep) = _PAGE_TYPE_EMPTY;
if (mm->context.noexec)
@@ -763,7 +763,7 @@ static inline int kvm_s390_test_and_clear_page_dirty(struct mm_struct *mm,
struct page *page;
unsigned int skey;
- if (!mm->context.pgstes)
+ if (!mm->context.has_pgste)
return -EINVAL;
rcp_lock(ptep);
pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
@@ -794,7 +794,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
int young;
unsigned long *pgste;
- if (!vma->vm_mm->context.pgstes)
+ if (!vma->vm_mm->context.has_pgste)
return 0;
physpage = pte_val(*ptep) & PAGE_MASK;
pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
@@ -844,7 +844,7 @@ static inline void __ptep_ipte(unsigned long address, pte_t *ptep)
static inline void ptep_invalidate(struct mm_struct *mm,
unsigned long address, pte_t *ptep)
{
- if (mm->context.pgstes) {
+ if (mm->context.has_pgste) {
rcp_lock(ptep);
__ptep_ipte(address, ptep);
ptep_rcp_copy(ptep);