[PATCH -next v7 6/6] riscv/mm: Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK
Palmer Dabbelt
palmer at dabbelt.com
Mon May 23 21:17:03 PDT 2022
On Sat, 07 May 2022 04:01:14 PDT (-0700), tongtiangen at huawei.com wrote:
> As commit d283d422c6c4 ("x86: mm: add x86_64 support for page table check")
> , enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on riscv.
>
> Add additional page table check stubs for page table helpers, these stubs
> can be used to check the existing page table entries.
>
> Signed-off-by: Tong Tiangen <tongtiangen at huawei.com>
> Reviewed-by: Pasha Tatashin <pasha.tatashin at soleen.com>
This doesn't build on rv32 (or presumably any other 32-bit arch)
something like this should do it
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 2b18e4410c4d..ea658ed6a1b1 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -690,11 +690,13 @@ static inline bool pmd_user_accessible_page(pmd_t pmd)
return pmd_leaf(pmd) && pmd_user(pmd);
}
+#ifdef CONFIG_64BIT
static inline bool pud_user_accessible_page(pud_t pud)
{
return pud_leaf(pud) && pud_user(pud);
}
-#endif
+#endif /* CONFIG_64BIT */
+#endif /* CONFIG_PAGE_TABLE_CHECK */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_huge(pmd_t pmd)
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 3692bea2ea2c..ac9bddfa1398 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -165,6 +165,7 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr,
}
EXPORT_SYMBOL(__page_table_check_pmd_clear);
+#if CONFIG_PGTABLE_LEVELS > 3
void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr,
pud_t pud)
{
@@ -177,6 +178,7 @@ void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr,
}
}
EXPORT_SYMBOL(__page_table_check_pud_clear);
+#endif
void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
@@ -208,6 +210,7 @@ void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr,
}
EXPORT_SYMBOL(__page_table_check_pmd_set);
+#if CONFIG_PGTABLE_LEVELS > 3
void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr,
pud_t *pudp, pud_t pud)
{
@@ -222,6 +225,7 @@ void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr,
}
}
EXPORT_SYMBOL(__page_table_check_pud_set);
+#endif
void __page_table_check_pte_clear_range(struct mm_struct *mm,
unsigned long addr,
with those changes this passes my tests, so
Acked-by: Palmer Dabbelt <palmer at rivosinc.com>
Feel free to take this along with the rest of them if that's easier, the
RISC-V bits are pretty light-weight. Also happy to do some sort of
shared tag once the other issues get sorted out.
Thanks!
> ---
> arch/riscv/Kconfig | 1 +
> arch/riscv/include/asm/pgtable.h | 71 +++++++++++++++++++++++++++++---
> 2 files changed, 66 insertions(+), 6 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 715390feb6ea..bb9fde09eea5 100644
> --- a/arch/riscv/Kconfig
> +++ b/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
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 046b44225623..62e733c85836 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/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, pte_t pteval)
>
> 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_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
> @@ -479,7 +493,11 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma,
> 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 = __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
> +
> + page_table_check_pte_clear(mm, address, pte);
> +
> + return pte;
> }
>
> #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
> @@ -546,6 +564,13 @@ static inline unsigned long pmd_pfn(pmd_t 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 +592,11 @@ 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 +630,39 @@ static inline pmd_t pmd_mkdirty(pmd_t pmd)
> 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 +688,11 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
> 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 = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0));
> +
> + page_table_check_pmd_clear(mm, address, pmd);
> +
> + return pmd;
> }
>
> #define __HAVE_ARCH_PMDP_SET_WRPROTECT
> @@ -648,6 +706,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
> 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 */
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