summaryrefslogtreecommitdiffstats
path: root/mm/debug_vm_pgtable.c
diff options
context:
space:
mode:
authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2020-10-15 20:04:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-16 11:11:14 -0700
commitcfc5bbc4e75da4e341b86822c3c8ab1f4d804de5 (patch)
treee30ea03e50e864d189c5991b7541fd67946018e1 /mm/debug_vm_pgtable.c
parent379c926d6334427b35fe7747f7758c865e20e9a9 (diff)
downloadlinux-cfc5bbc4e75da4e341b86822c3c8ab1f4d804de5.tar.bz2
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: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Anshuman 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: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/debug_vm_pgtable.c')
-rw-r--r--mm/debug_vm_pgtable.c13
1 files 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)