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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: [PATCH v2 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value
Date: Wed, 19 Aug 2020 18:30:57 +0530	[thread overview]
Message-ID: <20200819130107.478414-4-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20200819130107.478414-1-aneesh.kumar@linux.ibm.com>

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>
---
 mm/debug_vm_pgtable.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 086309fb9b6f..57259e2dbd17 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -44,10 +44,13 @@
  * 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)
+#define PPC64_SKIP_MASK		GENMASK(62, 62)
+#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)
-- 
2.26.2



  parent reply	other threads:[~2020-08-19 13:02 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-19 13:00 [PATCH v2 00/13] mm/debug_vm_pgtable fixes Aneesh Kumar K.V
2020-08-19 13:00 ` [PATCH v2 01/13] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Aneesh Kumar K.V
2020-08-19 13:00 ` [PATCH v2 02/13] powerpc/mm: Move setting pte specific flags to pfn_pte Aneesh Kumar K.V
2020-08-19 13:00 ` Aneesh Kumar K.V [this message]
2020-08-19 13:00 ` [PATCH v2 04/13] mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support Aneesh Kumar K.V
2020-08-19 16:29   ` kernel test robot
2020-08-20  5:31     ` Aneesh Kumar K.V
2020-08-21  8:38   ` Anshuman Khandual
2020-08-19 13:00 ` [PATCH v2 05/13] mm/debug_vm_pgtable/savedwrite: Enable savedwrite test with CONFIG_NUMA_BALANCING Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 06/13] mm/debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd/pud_at Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry Aneesh Kumar K.V
2020-08-20 14:32   ` Christophe Leroy
2020-08-21  7:14     ` Aneesh Kumar K.V
2020-08-21  8:20       ` Anshuman Khandual
2020-08-19 13:01 ` [PATCH v2 08/13] mm/debug_vm_pgtable/thp: Use page table depost/withdraw with THP Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 09/13] mm/debug_vm_pgtable/locks: Move non page table modifying test together Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 10/13] mm/debug_vm_pgtable/locks: Take correct page table lock Aneesh Kumar K.V
2020-08-21  8:03   ` Anshuman Khandual
2020-08-21  8:08     ` Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 11/13] mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 12/13] mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64 Aneesh Kumar K.V
2020-08-19 13:01 ` [PATCH v2 13/13] mm/debug_vm_pgtable: populate a pte entry before fetching it Aneesh Kumar K.V
2020-08-19 13:45 ` [PATCH v2 00/13] mm/debug_vm_pgtable fixes Aneesh Kumar K.V
2020-08-21  3:33   ` Anshuman Khandual
2020-08-21  4:20     ` Anshuman Khandual
2020-08-21  6:53     ` Aneesh Kumar K.V
2020-08-21  8:01       ` Anshuman Khandual
2020-08-21  8:10         ` Aneesh Kumar K.V
2020-08-21  8:50           ` Aneesh Kumar K.V
2020-08-21  9:09             ` Anshuman Khandual
2020-08-21  8:51 ` Anshuman Khandual
2020-09-01  8:03   ` Christophe Leroy
2020-09-01  9:11     ` Anshuman Khandual

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