# Re: \[PATCH v16 06/13\] mm/page\_table\_check: Reinstate address parameter in \[\_\_\]page\_table\_check\_pud\_clear() - From: Alexandre Ghiti \ - Date: 2025-08-14 12:11:49 - List: linuxppc-dev - Page: https://ratatoskr.run/linuxppc-dev/2025/08/3170198 - Thread: https://ratatoskr.run/linuxppc-dev/2025/08/3167646/t.md ```text On 8/13/25 08:26, Andrew Donnellan wrote: > From: Rohan McLure > > This reverts commit 931c38e16499 ("mm/page_table_check: remove unused > parameter in [__]page_table_check_pud_clear"). > > Reinstate previously unused parameters for the purpose of supporting > powerpc platforms, as many do not encode user/kernel ownership of the > page in the pte, but instead in the address of the access. > > [ajd@linux.ibm.com: rebase on arm64 changes] > Signed-off-by: Rohan McLure > Reviewed-by: Pasha Tatashin > Acked-by: Ingo Molnar # x86 > Signed-off-by: Andrew Donnellan > --- > v15: rebase > --- > arch/arm64/include/asm/pgtable.h | 2 +- > arch/x86/include/asm/pgtable.h | 2 +- > include/linux/page_table_check.h | 11 +++++++---- > include/linux/pgtable.h | 2 +- > mm/page_table_check.c | 5 +++-- > 5 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 06ea6a4f300b..81f06e5e32b2 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1374,7 +1374,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm, > break; > #ifndef __PAGETABLE_PMD_FOLDED > case PUD_SIZE: > - page_table_check_pud_clear(mm, pte_pud(pte)); > + page_table_check_pud_clear(mm, address, pte_pud(pte)); > break; > #endif > default: > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h > index 8ee301b16b50..8b45e0c41923 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -1329,7 +1329,7 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, > { > pud_t pud = native_pudp_get_and_clear(pudp); > > - page_table_check_pud_clear(mm, pud); > + page_table_check_pud_clear(mm, addr, pud); > > return pud; > } > diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h > index 66e109238416..808cc3a48c28 100644 > --- a/include/linux/page_table_check.h > +++ b/include/linux/page_table_check.h > @@ -16,7 +16,8 @@ extern struct page_ext_operations page_table_check_ops; > void __page_table_check_zero(struct page *page, unsigned int order); > void __page_table_check_pte_clear(struct mm_struct *mm, pte_t pte); > void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd); > -void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud); > +void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr, > + pud_t pud); > void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, pte_t pte, unsigned int nr); > void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr, > @@ -59,12 +60,13 @@ static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd) > __page_table_check_pmd_clear(mm, pmd); > } > > -static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud) > +static inline void page_table_check_pud_clear(struct mm_struct *mm, > + unsigned long addr, pud_t pud) > { > if (static_branch_likely(&page_table_check_disabled)) > return; > > - __page_table_check_pud_clear(mm, pud); > + __page_table_check_pud_clear(mm, addr, pud); > } > > static inline void page_table_check_ptes_set(struct mm_struct *mm, > @@ -123,7 +125,8 @@ static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd) > { > } > > -static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud) > +static inline void page_table_check_pud_clear(struct mm_struct *mm, > + unsigned long addr, pud_t pud) > { > } > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 8aab3fa19c85..28fcff844b63 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -661,7 +661,7 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, > pud_t pud = *pudp; > > pud_clear(pudp); > - page_table_check_pud_clear(mm, pud); > + page_table_check_pud_clear(mm, address, pud); > > return pud; > } > diff --git a/mm/page_table_check.c b/mm/page_table_check.c > index 0957767a2940..bd1242087a35 100644 > --- a/mm/page_table_check.c > +++ b/mm/page_table_check.c > @@ -167,7 +167,8 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd) > } > EXPORT_SYMBOL(__page_table_check_pmd_clear); > > -void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud) > +void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr, > + pud_t pud) > { > if (&init_mm == mm) > return; > @@ -246,7 +247,7 @@ void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr, > return; > > for (i = 0; i < nr; i++) > - __page_table_check_pud_clear(mm, *(pudp + i)); > + __page_table_check_pud_clear(mm, addr + PUD_SIZE * i, *(pudp + i)); > if (pud_user_accessible_page(pud)) > page_table_check_set(pud_pfn(pud), stride * nr, pud_write(pud)); > } So this made me realize we (riscv) did not implement pudp_huge_get_and_clear(), which was a mistake since we support THP PUD. I have implemented this function in this patch https://lore.kernel.org/all/20250814-dev-alex-thp_pud_xchg-v1-1-b4704dfae206@rivosinc.com/T/#u That's a fix so I'll merge it in 6.17 (at least I'll try) so your patchset will break the build on riscv, I'll keep you posted when it gets merged! Thanks, Alex ```