[PATCH v16 12/13] powerpc: mm: Use set_pte_at_unchecked() for internal usages
From: Andrew Donnellan <hidden>
Date: 2025-08-13 06:28:21
Also in:
linux-mm, linux-riscv, linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Rohan McLure <redacted>
In the new set_ptes() API, set_pte_at() (a special case of set_ptes())
is intended to be instrumented by the page table check facility. There
are however several other routines that constitute the API for setting
page table entries, including set_pmd_at() among others. Such routines
are themselves implemented in terms of set_ptes_at().
A future patch providing support for page table checking on powerpc
must take care to avoid duplicate calls to
page_table_check_p{te,md,ud}_set(). Allow for assignment of pte entries
without instrumentation through the set_pte_at_unchecked() routine
introduced in this patch.
Cause API-facing routines that call set_pte_at() to instead call
set_pte_at_unchecked(), which will remain uninstrumented by page
table check. set_ptes() is itself implemented by calls to
__set_pte_at(), so this eliminates redundant code.
[ajd@linux.ibm.com: don't change to unchecked for early boot/kernel mappings]
Signed-off-by: Rohan McLure <redacted>
Signed-off-by: Andrew Donnellan <redacted>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
---
v13: don't use the unchecked version for early-boot kernel mappings (Pasha)
---
arch/powerpc/include/asm/pgtable.h | 2 ++
arch/powerpc/mm/book3s64/pgtable.c | 6 +++---
arch/powerpc/mm/book3s64/radix_pgtable.c | 6 +++---
arch/powerpc/mm/pgtable.c | 8 ++++++++
4 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index d0938e9c33fb..4fe970992147 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h@@ -46,6 +46,8 @@ struct mm_struct; void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte, unsigned int nr); #define set_ptes set_ptes +void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte); #define update_mmu_cache(vma, addr, ptep) \ update_mmu_cache_range(NULL, vma, addr, ptep, 1)
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index c9431ae7f78a..ff0c5a1988f8 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c@@ -127,7 +127,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr, WARN_ON(!(pmd_leaf(pmd))); #endif trace_hugepage_set_pmd(addr, pmd_val(pmd)); - return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); + return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); } void set_pud_at(struct mm_struct *mm, unsigned long addr,
@@ -144,7 +144,7 @@ void set_pud_at(struct mm_struct *mm, unsigned long addr, WARN_ON(!(pud_leaf(pud))); #endif trace_hugepage_set_pud(addr, pud_val(pud)); - return set_pte_at(mm, addr, pudp_ptep(pudp), pud_pte(pud)); + return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud)); } static void do_serialize(void *arg)
@@ -549,7 +549,7 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, if (radix_enabled()) return radix__ptep_modify_prot_commit(vma, addr, ptep, old_pte, pte); - set_pte_at(vma->vm_mm, addr, ptep, pte); + set_pte_at_unchecked(vma->vm_mm, addr, ptep, pte); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index be523e5fe9c5..8c3b0f1750e4 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c@@ -1606,7 +1606,7 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma, (atomic_read(&mm->context.copros) > 0)) radix__flush_tlb_page(vma, addr); - set_pte_at(mm, addr, ptep, pte); + set_pte_at_unchecked(mm, addr, ptep, pte); } int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
@@ -1617,7 +1617,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) if (!radix_enabled()) return 0; - set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud); + set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pud); return 1; }
@@ -1664,7 +1664,7 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) if (!radix_enabled()) return 0; - set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd); + set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pmd); return 1; }
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index dfaa9fd86f7e..bf90becb6cd6 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c@@ -224,6 +224,14 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, } } +void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte) +{ + VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep)); + pte = set_pte_filter(pte, addr); + __set_pte_at(mm, addr, ptep, pte, 0); +} + void unmap_kernel_page(unsigned long va) { pmd_t *pmdp = pmd_off_k(va);
--
2.50.1