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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-18 08:27:36 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-18 08:28:13 -0400
commitf481bfafd36e621d6cbc62d4b25f74811410aef7 (patch)
tree781f98037ec772f2b7d480d5642135f7c1ec8b89 /arch/s390/mm/pgtable.c
parent2887fc5aa60803b9d6d38c79248805f08d8b0e28 (diff)
[S390] make page table walking more robust
Make page table walking on s390 more robust. The current code requires that the pgd/pud/pmd/pte loop is only done for address ranges that are below the end address of the last vma of the address space. But this is not always true, e.g. the generic page table walker does not guarantee this. Change TASK_SIZE/TASK_SIZE_OF to reflect the current size of the address space. This makes the generic page table walker happy but it breaks the upgrade of a 3 level page table to a 4 level page table. To make the upgrade work again another fix is required. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/pgtable.c')
-rw-r--r--arch/s390/mm/pgtable.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 0767827540b1..6b6ddc4ea02b 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -117,6 +117,7 @@ repeat:
117 crst_table_init(table, entry); 117 crst_table_init(table, entry);
118 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd); 118 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
119 mm->pgd = (pgd_t *) table; 119 mm->pgd = (pgd_t *) table;
120 mm->task_size = mm->context.asce_limit;
120 table = NULL; 121 table = NULL;
121 } 122 }
122 spin_unlock(&mm->page_table_lock); 123 spin_unlock(&mm->page_table_lock);
@@ -154,6 +155,7 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
154 BUG(); 155 BUG();
155 } 156 }
156 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN); 157 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
158 mm->task_size = mm->context.asce_limit;
157 crst_table_free(mm, (unsigned long *) pgd); 159 crst_table_free(mm, (unsigned long *) pgd);
158 } 160 }
159 update_mm(mm, current); 161 update_mm(mm, current);