The patch titled
Subject: mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
has been added to the -mm mm-unstable branch. Its filename is
mm-debug_vm_pgtable-use-pxdp_get-for-accessing-page-table-entries.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-debug_vm_pgtable-use-pxdp_get-for-accessing-page-table-entries.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
Date: Tue, 10 Sep 2024 17:27:46 +0530
This replaces all the existing READ_ONCE() based page table accesses with
respective pxdp_get() helpers. Although these helpers might also fallback
to READ_ONCE() as default, but they do provide an opportunity for various
platforms to override when required. This change is a step in direction to
replace all page table entry accesses with respective pxdp_get() helpers.
Link: https://lkml.kernel.org/r/20240910115746.514454-1-anshuman.khandual@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/debug_vm_pgtable.c | 50 ++++++++++++++++++++--------------------
1 file changed, 25 insertions(+), 25 deletions(-)
--- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-use-pxdp_get-for-accessing-page-table-entries
+++ a/mm/debug_vm_pgtable.c
@@ -231,10 +231,10 @@ static void __init pmd_advanced_tests(st
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
flush_dcache_page(page);
pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(pmd_write(pmd));
pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(!pmd_none(pmd));
pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
@@ -245,10 +245,10 @@ static void __init pmd_advanced_tests(st
pmd = pmd_mkwrite(pmd, args->vma);
pmd = pmd_mkdirty(pmd);
pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(!pmd_none(pmd));
pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
@@ -256,7 +256,7 @@ static void __init pmd_advanced_tests(st
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
flush_dcache_page(page);
pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(pmd_young(pmd));
/* Clear the pte entries */
@@ -357,12 +357,12 @@ static void __init pud_advanced_tests(st
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_set_wrprotect(args->mm, vaddr, args->pudp);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(pud_write(pud));
#ifndef __PAGETABLE_PMD_FOLDED
pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
@@ -374,12 +374,12 @@ static void __init pud_advanced_tests(st
pud = pud_mkwrite(pud);
pud = pud_mkdirty(pud);
pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
#ifndef __PAGETABLE_PMD_FOLDED
pudp_huge_get_and_clear_full(args->vma, vaddr, args->pudp, 1);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
@@ -389,7 +389,7 @@ static void __init pud_advanced_tests(st
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(pud_young(pud));
pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
@@ -441,7 +441,7 @@ static void __init pmd_huge_tests(struct
WRITE_ONCE(*args->pmdp, __pmd(0));
WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
WARN_ON(!pmd_clear_huge(args->pmdp));
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(!pmd_none(pmd));
}
@@ -461,7 +461,7 @@ static void __init pud_huge_tests(struct
WRITE_ONCE(*args->pudp, __pud(0));
WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
WARN_ON(!pud_clear_huge(args->pudp));
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(!pud_none(pud));
}
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
@@ -490,7 +490,7 @@ static void __init pgd_basic_tests(struc
#ifndef __PAGETABLE_PUD_FOLDED
static void __init pud_clear_tests(struct pgtable_debug_args *args)
{
- pud_t pud = READ_ONCE(*args->pudp);
+ pud_t pud = pudp_get(args->pudp);
if (mm_pmd_folded(args->mm))
return;
@@ -498,7 +498,7 @@ static void __init pud_clear_tests(struc
pr_debug("Validating PUD clear\n");
WARN_ON(pud_none(pud));
pud_clear(args->pudp);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(!pud_none(pud));
}
@@ -515,7 +515,7 @@ static void __init pud_populate_tests(st
* Hence this must not qualify as pud_bad().
*/
pud_populate(args->mm, args->pudp, args->start_pmdp);
- pud = READ_ONCE(*args->pudp);
+ pud = pudp_get(args->pudp);
WARN_ON(pud_bad(pud));
}
#else /* !__PAGETABLE_PUD_FOLDED */
@@ -526,7 +526,7 @@ static void __init pud_populate_tests(st
#ifndef __PAGETABLE_P4D_FOLDED
static void __init p4d_clear_tests(struct pgtable_debug_args *args)
{
- p4d_t p4d = READ_ONCE(*args->p4dp);
+ p4d_t p4d = p4dp_get(args->p4dp);
if (mm_pud_folded(args->mm))
return;
@@ -534,7 +534,7 @@ static void __init p4d_clear_tests(struc
pr_debug("Validating P4D clear\n");
WARN_ON(p4d_none(p4d));
p4d_clear(args->p4dp);
- p4d = READ_ONCE(*args->p4dp);
+ p4d = p4dp_get(args->p4dp);
WARN_ON(!p4d_none(p4d));
}
@@ -553,13 +553,13 @@ static void __init p4d_populate_tests(st
pud_clear(args->pudp);
p4d_clear(args->p4dp);
p4d_populate(args->mm, args->p4dp, args->start_pudp);
- p4d = READ_ONCE(*args->p4dp);
+ p4d = p4dp_get(args->p4dp);
WARN_ON(p4d_bad(p4d));
}
static void __init pgd_clear_tests(struct pgtable_debug_args *args)
{
- pgd_t pgd = READ_ONCE(*(args->pgdp));
+ pgd_t pgd = pgdp_get(args->pgdp);
if (mm_p4d_folded(args->mm))
return;
@@ -567,7 +567,7 @@ static void __init pgd_clear_tests(struc
pr_debug("Validating PGD clear\n");
WARN_ON(pgd_none(pgd));
pgd_clear(args->pgdp);
- pgd = READ_ONCE(*args->pgdp);
+ pgd = pgdp_get(args->pgdp);
WARN_ON(!pgd_none(pgd));
}
@@ -586,7 +586,7 @@ static void __init pgd_populate_tests(st
p4d_clear(args->p4dp);
pgd_clear(args->pgdp);
pgd_populate(args->mm, args->pgdp, args->start_p4dp);
- pgd = READ_ONCE(*args->pgdp);
+ pgd = pgdp_get(args->pgdp);
WARN_ON(pgd_bad(pgd));
}
#else /* !__PAGETABLE_P4D_FOLDED */
@@ -627,12 +627,12 @@ static void __init pte_clear_tests(struc
static void __init pmd_clear_tests(struct pgtable_debug_args *args)
{
- pmd_t pmd = READ_ONCE(*args->pmdp);
+ pmd_t pmd = pmdp_get(args->pmdp);
pr_debug("Validating PMD clear\n");
WARN_ON(pmd_none(pmd));
pmd_clear(args->pmdp);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(!pmd_none(pmd));
}
@@ -646,7 +646,7 @@ static void __init pmd_populate_tests(st
* Hence this must not qualify as pmd_bad().
*/
pmd_populate(args->mm, args->pmdp, args->start_ptep);
- pmd = READ_ONCE(*args->pmdp);
+ pmd = pmdp_get(args->pmdp);
WARN_ON(pmd_bad(pmd));
}
@@ -1251,7 +1251,7 @@ static int __init init_args(struct pgtab
ret = -ENOMEM;
goto error;
}
- args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));
+ args->start_ptep = pmd_pgtable(pmdp_get(args->pmdp));
WARN_ON(!args->start_ptep);
init_fixed_pfns(args);
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-debug_vm_pgtable-use-pxdp_get-for-accessing-page-table-entries.patch
