From f481bfafd36e621d6cbc62d4b25f74811410aef7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 18 Mar 2009 13:27:36 +0100 Subject: [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 --- arch/s390/include/asm/processor.h | 5 ++--- arch/s390/mm/mmap.c | 4 ++-- arch/s390/mm/pgtable.c | 2 ++ 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 066b99502e0..db4523fe38a 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -61,7 +61,7 @@ extern void print_cpu_info(struct cpuinfo_S390 *); extern int get_cpu_capability(unsigned int *); /* - * User space process size: 2GB for 31 bit, 4TB for 64 bit. + * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit. */ #ifndef __s390x__ @@ -70,8 +70,7 @@ extern int get_cpu_capability(unsigned int *); #else /* __s390x__ */ -#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk,TIF_31BIT) ? \ - (1UL << 31) : (1UL << 53)) +#define TASK_SIZE_OF(tsk) ((tsk)->mm->context.asce_limit) #define TASK_UNMAPPED_BASE (test_thread_flag(TIF_31BIT) ? \ (1UL << 30) : (1UL << 41)) #define TASK_SIZE TASK_SIZE_OF(current) diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index 5932a824547..346dd0c5cbd 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -35,7 +35,7 @@ * Leave an at least ~128 MB hole. */ #define MIN_GAP (128*1024*1024) -#define MAX_GAP (TASK_SIZE/6*5) +#define MAX_GAP (STACK_TOP/6*5) static inline unsigned long mmap_base(void) { @@ -46,7 +46,7 @@ static inline unsigned long mmap_base(void) else if (gap > MAX_GAP) gap = MAX_GAP; - return TASK_SIZE - (gap & PAGE_MASK); + return STACK_TOP - (gap & PAGE_MASK); } static inline int mmap_is_legacy(void) diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 0767827540b..6b6ddc4ea02 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -117,6 +117,7 @@ repeat: crst_table_init(table, entry); pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd); mm->pgd = (pgd_t *) table; + mm->task_size = mm->context.asce_limit; table = NULL; } spin_unlock(&mm->page_table_lock); @@ -154,6 +155,7 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit) BUG(); } mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN); + mm->task_size = mm->context.asce_limit; crst_table_free(mm, (unsigned long *) pgd); } update_mm(mm, current); -- cgit v1.2.3-18-g5258