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.kumar@xxxxxxxxxxxxx> > --- > 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.khandual@xxxxxxx>
