The patch titled
Subject: powerpc: mm: support page table check
has been added to the -mm mm-unstable branch. Its filename is
powerpc-mm-support-page-table-check.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/powerpc-mm-support-page-table-check.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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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Rohan McLure <rmclure@xxxxxxxxxxxxx>
Subject: powerpc: mm: support page table check
Date: Wed, 12 Feb 2025 03:14:04 +1100
On creation and clearing of a page table mapping, instrument such calls by
invoking page_table_check_pte_set and page_table_check_pte_clear
respectively. These calls serve as a sanity check against illegal
mappings.
Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK for all platforms.
See also:
riscv support in commit 3fee229a8eb9 ("riscv/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
arm64 in commit 42b2547137f5 ("arm64/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
x86_64 in commit d283d422c6c4 ("x86: mm: add x86_64 support for page table
check")
[ajd@xxxxxxxxxxxxx: rebase]
Link: https://lkml.kernel.org/r/20250211161404.850215-12-ajd@xxxxxxxxxxxxx
Signed-off-by: Rohan McLure <rmclure@xxxxxxxxxxxxx>
Signed-off-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Sweet Tea Dorminy <sweettea-kernel@xxxxxxxxxx>
Cc: <x86@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 1
arch/powerpc/include/asm/book3s/32/pgtable.h | 7 ++
arch/powerpc/include/asm/book3s/64/pgtable.h | 45 +++++++++++++----
arch/powerpc/include/asm/nohash/pgtable.h | 8 ++-
arch/powerpc/mm/book3s64/hash_pgtable.c | 4 +
arch/powerpc/mm/book3s64/pgtable.c | 11 +++-
arch/powerpc/mm/book3s64/radix_pgtable.c | 3 +
arch/powerpc/mm/pgtable.c | 4 +
8 files changed, 68 insertions(+), 15 deletions(-)
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -202,6 +202,7 @@ void unmap_kernel_page(unsigned long va)
#ifndef __ASSEMBLY__
#include <linux/sched.h>
#include <linux/threads.h>
+#include <linux/page_table_check.h>
/* Bits to mask out from a PGD to get to the PUD page */
#define PGD_MASKED_BITS 0
@@ -315,7 +316,11 @@ static inline int __ptep_test_and_clear_
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
- return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+ pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+
+ page_table_check_pte_clear(mm, addr, old_pte);
+
+ return old_pte;
}
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -145,6 +145,8 @@
#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
#ifndef __ASSEMBLY__
+#include <linux/page_table_check.h>
+
/*
* page table defines
*/
@@ -417,8 +419,11 @@ static inline void huge_ptep_set_wrprote
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
- unsigned long old = pte_update(mm, addr, ptep, ~0UL, 0, 0);
- return __pte(old);
+ pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+
+ page_table_check_pte_clear(mm, addr, old_pte);
+
+ return old_pte;
}
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
@@ -427,11 +432,16 @@ static inline pte_t ptep_get_and_clear_f
pte_t *ptep, int full)
{
if (full && radix_enabled()) {
+ pte_t old_pte;
+
/*
* We know that this is a full mm pte clear and
* hence can be sure there is no parallel set_pte.
*/
- return radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+ old_pte = radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+ page_table_check_pte_clear(mm, addr, old_pte);
+
+ return old_pte;
}
return ptep_get_and_clear(mm, addr, ptep);
}
@@ -1309,19 +1319,34 @@ extern int pudp_test_and_clear_young(str
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp)
{
- if (radix_enabled())
- return radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
- return hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+ pmd_t old_pmd;
+
+ if (radix_enabled()) {
+ old_pmd = radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
+ } else {
+ old_pmd = hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+ }
+
+ page_table_check_pmd_clear(mm, addr, old_pmd);
+
+ return old_pmd;
}
#define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pud_t *pudp)
{
- if (radix_enabled())
- return radix__pudp_huge_get_and_clear(mm, addr, pudp);
- BUG();
- return *pudp;
+ pud_t old_pud;
+
+ if (radix_enabled()) {
+ old_pud = radix__pudp_huge_get_and_clear(mm, addr, pudp);
+ } else {
+ BUG();
+ }
+
+ page_table_check_pud_clear(mm, addr, old_pud);
+
+ return old_pud;
}
static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
--- a/arch/powerpc/include/asm/nohash/pgtable.h~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/include/asm/nohash/pgtable.h
@@ -29,6 +29,8 @@ static inline pte_basic_t pte_update(str
#ifndef __ASSEMBLY__
+#include <linux/page_table_check.h>
+
extern int icache_44x_need_flush;
#ifndef pte_huge_size
@@ -122,7 +124,11 @@ static inline void ptep_set_wrprotect(st
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
- return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+ pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+
+ page_table_check_pte_clear(mm, addr, old_pte);
+
+ return old_pte;
}
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
--- a/arch/powerpc/Kconfig~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/Kconfig
@@ -172,6 +172,7 @@ config PPC
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC_BOOK3S || PPC_8xx
+ select ARCH_SUPPORTS_PAGE_TABLE_CHECK
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_USE_MEMTEST
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -8,6 +8,7 @@
#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/mm.h>
+#include <linux/page_table_check.h>
#include <linux/stop_machine.h>
#include <asm/sections.h>
@@ -231,6 +232,9 @@ pmd_t hash__pmdp_collapse_flush(struct v
pmd = *pmdp;
pmd_clear(pmdp);
+
+ page_table_check_pmd_clear(vma->vm_mm, address, pmd);
+
/*
* Wait for all pending hash_page to finish. This is needed
* in case of subpage collapse. When we collapse normal pages
--- a/arch/powerpc/mm/book3s64/pgtable.c~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/mm/book3s64/pgtable.c
@@ -10,6 +10,7 @@
#include <linux/pkeys.h>
#include <linux/debugfs.h>
#include <linux/proc_fs.h>
+#include <linux/page_table_check.h>
#include <misc/cxl-base.h>
#include <asm/pgalloc.h>
@@ -129,6 +130,7 @@ void set_pmd_at(struct mm_struct *mm, un
WARN_ON(!(pmd_leaf(pmd)));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
+ page_table_check_pmd_set(mm, addr, pmdp, pmd);
return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
@@ -146,6 +148,7 @@ void set_pud_at(struct mm_struct *mm, un
WARN_ON(!(pud_leaf(pud)));
#endif
trace_hugepage_set_pud(addr, pud_val(pud));
+ page_table_check_pud_set(mm, addr, pudp, pud);
return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud));
}
@@ -181,12 +184,14 @@ void serialize_against_pte_lookup(struct
pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
- unsigned long old_pmd;
+ pmd_t old_pmd;
VM_WARN_ON_ONCE(!pmd_present(*pmdp));
- old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
+ old_pmd = __pmd(pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID));
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
- return __pmd(old_pmd);
+ page_table_check_pmd_clear(vma->vm_mm, address, old_pmd);
+
+ return old_pmd;
}
pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -14,6 +14,7 @@
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/mm.h>
+#include <linux/page_table_check.h>
#include <linux/hugetlb.h>
#include <linux/string_helpers.h>
#include <linux/memory.h>
@@ -1454,6 +1455,8 @@ pmd_t radix__pmdp_collapse_flush(struct
pmd = *pmdp;
pmd_clear(pmdp);
+ page_table_check_pmd_clear(vma->vm_mm, address, pmd);
+
radix__flush_tlb_collapsed_pmd(vma->vm_mm, address);
return pmd;
--- a/arch/powerpc/mm/pgtable.c~powerpc-mm-support-page-table-check
+++ a/arch/powerpc/mm/pgtable.c
@@ -22,6 +22,7 @@
#include <linux/mm.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
+#include <linux/page_table_check.h>
#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
@@ -206,6 +207,9 @@ void set_ptes(struct mm_struct *mm, unsi
* and not hw_valid ptes. Hence there is no translation cache flush
* involved that need to be batched.
*/
+
+ page_table_check_ptes_set(mm, addr, ptep, pte, nr);
+
for (;;) {
/*
_
Patches currently in -mm which might be from rmclure@xxxxxxxxxxxxx are
mm-page_table_check-reinstate-address-parameter-in-page_table_check_pud_set.patch
mm-page_table_check-reinstate-address-parameter-in-page_table_check_pmd_set.patch
mm-page_table_check-provide-addr-parameter-to-page_table_check_pte_set.patch
mm-page_table_check-reinstate-address-parameter-in-page_table_check_pud_clear.patch
mm-page_table_check-reinstate-address-parameter-in-page_table_check_pmd_clear.patch
mm-page_table_check-reinstate-address-parameter-in-page_table_check_pte_clear.patch
mm-provide-address-parameter-to-ptemdud_user_accessible_page.patch
powerpc-mm-add-pud_pfn-stub.patch
powerpc-mm-implement-_user_accessible_page-for-ptes.patch
powerpc-mm-use-set_pte_at_unchecked-for-internal-usages.patch
powerpc-mm-support-page-table-check.patch
