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 v4 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry
Date: Wed, 2 Sep 2020 17:12:16 +0530 [thread overview]
Message-ID: <20200902114222.181353-8-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20200902114222.181353-1-aneesh.kumar@linux.ibm.com>
set_pte_at() should not be used to set a pte entry at locations that
already holds a valid pte entry. Architectures like ppc64 don't do TLB
invalidate in set_pte_at() and hence expect it to be used to set locations
that are not a valid PTE.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
mm/debug_vm_pgtable.c | 35 +++++++++++++++--------------------
1 file changed, 15 insertions(+), 20 deletions(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 9cafed39c236..de333871f407 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -79,15 +79,18 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
{
pte_t pte = pfn_pte(pfn, prot);
+ /*
+ * Architectures optimize set_pte_at by avoiding TLB flush.
+ * This requires set_pte_at to be not used to update an
+ * existing pte entry. Clear pte before we do set_pte_at
+ */
+
pr_debug("Validating PTE advanced\n");
pte = pfn_pte(pfn, prot);
set_pte_at(mm, vaddr, ptep, pte);
ptep_set_wrprotect(mm, vaddr, ptep);
pte = ptep_get(ptep);
WARN_ON(pte_write(pte));
-
- pte = pfn_pte(pfn, prot);
- set_pte_at(mm, vaddr, ptep, pte);
ptep_get_and_clear(mm, vaddr, ptep);
pte = ptep_get(ptep);
WARN_ON(!pte_none(pte));
@@ -101,13 +104,11 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
pte = ptep_get(ptep);
WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
-
- pte = pfn_pte(pfn, prot);
- set_pte_at(mm, vaddr, ptep, pte);
ptep_get_and_clear_full(mm, vaddr, ptep, 1);
pte = ptep_get(ptep);
WARN_ON(!pte_none(pte));
+ pte = pfn_pte(pfn, prot);
pte = pte_mkyoung(pte);
set_pte_at(mm, vaddr, ptep, pte);
ptep_test_and_clear_young(vma, vaddr, ptep);
@@ -169,9 +170,6 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
pmdp_set_wrprotect(mm, vaddr, pmdp);
pmd = READ_ONCE(*pmdp);
WARN_ON(pmd_write(pmd));
-
- pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
- set_pmd_at(mm, vaddr, pmdp, pmd);
pmdp_huge_get_and_clear(mm, vaddr, pmdp);
pmd = READ_ONCE(*pmdp);
WARN_ON(!pmd_none(pmd));
@@ -185,13 +183,11 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
pmd = READ_ONCE(*pmdp);
WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
-
- pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
- set_pmd_at(mm, vaddr, pmdp, pmd);
pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
pmd = READ_ONCE(*pmdp);
WARN_ON(!pmd_none(pmd));
+ pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
pmd = pmd_mkyoung(pmd);
set_pmd_at(mm, vaddr, pmdp, pmd);
pmdp_test_and_clear_young(vma, vaddr, pmdp);
@@ -292,17 +288,9 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
WARN_ON(pud_write(pud));
#ifndef __PAGETABLE_PMD_FOLDED
- pud = pud_mkhuge(pfn_pud(pfn, prot));
- set_pud_at(mm, vaddr, pudp, pud);
pudp_huge_get_and_clear(mm, vaddr, pudp);
pud = READ_ONCE(*pudp);
WARN_ON(!pud_none(pud));
-
- pud = pud_mkhuge(pfn_pud(pfn, prot));
- set_pud_at(mm, vaddr, pudp, pud);
- pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
- pud = READ_ONCE(*pudp);
- WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pud_mkhuge(pfn_pud(pfn, prot));
@@ -315,6 +303,13 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
pud = READ_ONCE(*pudp);
WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
+#ifndef __PAGETABLE_PMD_FOLDED
+ pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+#endif /* __PAGETABLE_PMD_FOLDED */
+
+ pud = pud_mkhuge(pfn_pud(pfn, prot));
pud = pud_mkyoung(pud);
set_pud_at(mm, vaddr, pudp, pud);
pudp_test_and_clear_young(vma, vaddr, pudp);
--
2.26.2
next prev parent reply other threads:[~2020-09-02 11:43 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 11:42 [PATCH v4 00/13] mm/debug_vm_pgtable fixes Aneesh Kumar K.V
2020-09-02 11:42 ` [PATCH v4 01/13] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Aneesh Kumar K.V
2020-09-02 11:42 ` [PATCH v4 02/13] powerpc/mm: Move setting pte specific flags to pfn_pte Aneesh Kumar K.V
2020-09-02 12:30 ` Christophe Leroy
2020-09-02 11:42 ` [PATCH v4 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value Aneesh Kumar K.V
2020-09-04 4:03 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 04/13] mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support Aneesh Kumar K.V
2020-09-02 12:40 ` Christophe Leroy
2020-09-02 12:53 ` Aneesh Kumar K.V
2020-09-04 4:08 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 05/13] mm/debug_vm_pgtable/savedwrite: Enable savedwrite test with CONFIG_NUMA_BALANCING Aneesh Kumar K.V
2020-09-04 4:09 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 06/13] mm/debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd/pud_at Aneesh Kumar K.V
2020-09-04 5:21 ` Anshuman Khandual
2020-09-02 11:42 ` Aneesh Kumar K.V [this message]
2020-09-04 5:34 ` [PATCH v4 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 08/13] mm/debug_vm_pgtable/locks: Move non page table modifying test together Aneesh Kumar K.V
2020-09-04 3:58 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 09/13] mm/debug_vm_pgtable/locks: Take correct page table lock Aneesh Kumar K.V
2020-09-04 5:39 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 10/13] mm/debug_vm_pgtable/thp: Use page table depost/withdraw with THP Aneesh Kumar K.V
2020-09-04 4:21 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 11/13] mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries Aneesh Kumar K.V
2020-09-04 6:03 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 12/13] mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64 Aneesh Kumar K.V
2020-09-04 6:19 ` Anshuman Khandual
2020-09-02 11:42 ` [PATCH v4 13/13] mm/debug_vm_pgtable: Avoid none pte in pte_clear_test Aneesh Kumar K.V
2020-09-11 2:13 ` Nathan Chancellor
2020-09-11 5:21 ` Aneesh Kumar K.V
2020-09-23 3:14 ` Anshuman Khandual
2020-10-11 20:02 ` Guenter Roeck
2020-10-12 4:29 ` Aneesh Kumar K.V
2020-09-02 11:46 ` Aneesh Kumar K.V
2020-09-04 4:16 ` Anshuman Khandual
2020-09-04 6:48 ` [PATCH v4 00/13] mm/debug_vm_pgtable fixes Anshuman Khandual
2020-09-04 15:26 ` Gerald Schaefer
2020-09-04 16:01 ` Gerald Schaefer
2020-09-04 17:53 ` Gerald Schaefer
2020-09-09 8:38 ` Anshuman Khandual
2020-09-08 15:39 ` Gerald Schaefer
2020-09-09 6:08 ` Aneesh Kumar K.V
2020-09-09 11:16 ` Gerald Schaefer
2020-09-09 8:15 ` Anshuman Khandual
2020-09-09 11:10 ` Gerald Schaefer
2020-09-09 8:08 ` Anshuman Khandual
2020-09-09 11:36 ` Gerald Schaefer
2020-09-13 11:03 ` [PATCH] mm/debug_vm_pgtable: Avoid doing memory allocation with pgtable_t mapped Aneesh Kumar K.V
2020-09-13 13:42 ` Matthew Wilcox
2020-10-13 20:58 ` [PATCH v4 00/13] mm/debug_vm_pgtable fixes Andrew Morton
2020-10-14 3:15 ` Aneesh Kumar K.V
2020-10-14 20:36 ` Andrew Morton
2020-10-15 2:59 ` Anshuman Khandual
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