Commit cfc5bbc4 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Linus Torvalds
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mm/debug_vm_pgtable/ppc64: avoid setting top bits in radom value 



ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE).  Avoid setting that
bit in random value.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lkml.kernel.org/r/20200902114222.181353-4-aneesh.kumar@linux.ibm.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 379c926d

mm/debug_vm_pgtable.c

+10 −3
Original line number Diff line number Diff line
@@ -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)