From: Rohan McLure <rmclure@xxxxxxxxxxxxx>
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.
Signed-off-by: Rohan McLure <rmclure@xxxxxxxxxxxxx>
[ajd: don't change to unchecked for early boot/kernel mappings]
Signed-off-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
---
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 3cae32c74fed..221cae4873b9 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 ce64abea9e3e..b4708b2cabba 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -129,7 +129,7 @@ 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,
@@ -146,7 +146,7 @@ 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)
@@ -557,7 +557,7 @@ 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 311e2112d782..1704381f5c3c 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1586,7 +1586,7 @@ 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)
@@ -1597,7 +1597,7 @@ 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;
}
@@ -1644,7 +1644,7 @@ 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 61df5aed7989..4cc9af7961ca 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);
--
2.48.1
