The patch titled
Subject: riscv: mm: add support for page table check
has been added to the -mm tree. Its filename is
riscv-mm-add-support-for-page-table-check.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/riscv-mm-add-support-for-page-table-check.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/riscv-mm-add-support-for-page-table-check.patch
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------------------------------------------------------
From: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Subject: riscv: mm: add support for page table check
As commit d283d422c6c4 ("x86: mm: add x86_64 support for page table
check"), add some necessary page table check hooks into routines that
modify user page tables.
Link: https://lkml.kernel.org/r/20220421082042.1167967-6-tongtiangen@xxxxxxxxxx
Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Guohanjun <guohanjun@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/riscv/Kconfig | 1
arch/riscv/include/asm/pgtable.h | 77 ++++++++++++++++++++++++++---
2 files changed, 72 insertions(+), 6 deletions(-)
--- a/arch/riscv/include/asm/pgtable.h~riscv-mm-add-support-for-page-table-check
+++ a/arch/riscv/include/asm/pgtable.h
@@ -114,6 +114,8 @@
#include <asm/pgtable-32.h>
#endif /* CONFIG_64BIT */
+#include <linux/page_table_check.h>
+
#ifdef CONFIG_XIP_KERNEL
#define XIP_FIXUP(addr) ({ \
uintptr_t __a = (uintptr_t)(addr); \
@@ -315,6 +317,11 @@ static inline int pte_exec(pte_t pte)
return pte_val(pte) & _PAGE_EXEC;
}
+static inline int pte_user(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_USER;
+}
+
static inline int pte_huge(pte_t pte)
{
return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
@@ -446,7 +453,7 @@ static inline void set_pte(pte_t *ptep,
void flush_icache_pte(pte_t pte);
-static inline void set_pte_at(struct mm_struct *mm,
+static inline void __set_pte_at(struct mm_struct *mm,
unsigned long addr, pte_t *ptep, pte_t pteval)
{
if (pte_present(pteval) && pte_exec(pteval))
@@ -455,10 +462,17 @@ static inline void set_pte_at(struct mm_
set_pte(ptep, pteval);
}
+static inline void set_pte_at(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep, pte_t pteval)
+{
+ page_table_check_pte_set(mm, addr, ptep, pteval);
+ __set_pte_at(mm, addr, ptep, pteval);
+}
+
static inline void pte_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
- set_pte_at(mm, addr, ptep, __pte(0));
+ __set_pte_at(mm, addr, ptep, __pte(0));
}
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
@@ -475,11 +489,21 @@ static inline int ptep_set_access_flags(
return true;
}
+static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long address, pte_t *ptep)
+{
+ return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
+}
+
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
unsigned long address, pte_t *ptep)
{
- return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
+ pte_t pte = __ptep_get_and_clear(mm, address, ptep);
+
+ page_table_check_pte_clear(mm, address, pte);
+
+ return pte;
}
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
@@ -546,6 +570,13 @@ static inline unsigned long pmd_pfn(pmd_
return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
}
+#define __pud_to_phys(pud) (pud_val(pud) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
+
+static inline unsigned long pud_pfn(pud_t pud)
+{
+ return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
+}
+
static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
@@ -567,6 +598,11 @@ static inline int pmd_young(pmd_t pmd)
return pte_young(pmd_pte(pmd));
}
+static inline int pmd_user(pmd_t pmd)
+{
+ return pte_user(pmd_pte(pmd));
+}
+
static inline pmd_t pmd_mkold(pmd_t pmd)
{
return pte_pmd(pte_mkold(pmd_pte(pmd)));
@@ -600,15 +636,39 @@ static inline pmd_t pmd_mkdirty(pmd_t pm
static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
- return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
+ page_table_check_pmd_set(mm, addr, pmdp, pmd);
+ return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
+}
+
+static inline int pud_user(pud_t pud)
+{
+ return pte_user(pud_pte(pud));
}
static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
pud_t *pudp, pud_t pud)
{
- return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
+ page_table_check_pud_set(mm, addr, pudp, pud);
+ return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
+}
+
+#ifdef CONFIG_PAGE_TABLE_CHECK
+static inline bool pte_user_accessible_page(pte_t pte)
+{
+ return pte_present(pte) && pte_user(pte);
}
+static inline bool pmd_user_accessible_page(pmd_t pmd)
+{
+ return pmd_leaf(pmd) && pmd_user(pmd);
+}
+
+static inline bool pud_user_accessible_page(pud_t pud)
+{
+ return pud_leaf(pud) && pud_user(pud);
+}
+#endif
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_huge(pmd_t pmd)
{
@@ -634,7 +694,11 @@ static inline int pmdp_test_and_clear_yo
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp)
{
- return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
+ pmd_t pmd = pte_pmd(__ptep_get_and_clear(mm, address, (pte_t *)pmdp));
+
+ page_table_check_pmd_clear(mm, address, pmd);
+
+ return pmd;
}
#define __HAVE_ARCH_PMDP_SET_WRPROTECT
@@ -648,6 +712,7 @@ static inline void pmdp_set_wrprotect(st
static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp, pmd_t pmd)
{
+ page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
--- a/arch/riscv/Kconfig~riscv-mm-add-support-for-page-table-check
+++ a/arch/riscv/Kconfig
@@ -38,6 +38,7 @@ config RISCV
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
select ARCH_SUPPORTS_HUGETLBFS if MMU
+ select ARCH_SUPPORTS_PAGE_TABLE_CHECK
select ARCH_USE_MEMTEST
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
select ARCH_WANT_FRAME_POINTERS
_
Patches currently in -mm which might be from tongtiangen@xxxxxxxxxx are
mm-page_table_check-using-pxd_size-instead-of-pxd_page_size.patch
mm-page_table_check-add-hooks-to-public-helpers.patch
riscv-mm-add-support-for-page-table-check.patch
