On 09/02/2020 05:12 PM, Aneesh Kumar K.V wrote:
> ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting
> that bit in random value.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
> ---
> mm/debug_vm_pgtable.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 086309fb9b6f..00649b47f6e0 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -44,10 +44,17 @@
> * entry type. But these bits might affect the ability to clear entries with
> * pxx_clear() because of how dynamic page table folding works on s390. So
> * while loading up the entries do not change the lower 4 bits. It does not
> - * have affect any other platform.
> + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
> + * used to mark a pte entry.
> */
> -#define S390_MASK_BITS 4
> -#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS)
> +#define S390_SKIP_MASK GENMASK(3, 0)
> +#if __BITS_PER_LONG == 64
> +#define PPC64_SKIP_MASK GENMASK(62, 62)
> +#else
> +#define PPC64_SKIP_MASK 0x0
> +#endif
> +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
> +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
> #define RANDOM_NZVALUE GENMASK(7, 0)
>
> static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
>
Reviewed-by: Anshuman Khandual <anshuman.khand...@arm.com>
