Messages in this thread | | | Date | Tue, 3 May 2022 09:13:20 +0800 | Subject | Re: [PATCH -next v6 5/6] arm64/mm: Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK | From | Tong Tiangen <> |
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在 2022/4/29 14:18, Anshuman Khandual 写道: > > > On 4/26/22 13:40, Tong Tiangen wrote: >> From: Kefeng Wang <wangkefeng.wang@huawei.com> >> >> As commit d283d422c6c4 ("x86: mm: add x86_64 support for page table check") >> , enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on arm64. >> >> 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: Kefeng Wang <wangkefeng.wang@huawei.com> >> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> >> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> >> --- >> arch/arm64/Kconfig | 1 + >> arch/arm64/include/asm/pgtable.h | 59 +++++++++++++++++++++++++++++--- >> 2 files changed, 55 insertions(+), 5 deletions(-) >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index 18a18a0e855d..c1509525ab8e 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -92,6 +92,7 @@ config ARM64 >> select ARCH_SUPPORTS_ATOMIC_RMW >> select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 >> select ARCH_SUPPORTS_NUMA_BALANCING >> + select ARCH_SUPPORTS_PAGE_TABLE_CHECK >> select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT >> select ARCH_WANT_DEFAULT_BPF_JIT >> select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index ad9b221963d4..fe17788a6885 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -33,6 +33,7 @@ >> #include <linux/mmdebug.h> >> #include <linux/mm_types.h> >> #include <linux/sched.h> >> +#include <linux/page_table_check.h> >> >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE >> #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE >> @@ -96,6 +97,7 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) >> #define pte_young(pte) (!!(pte_val(pte) & PTE_AF)) >> #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL)) >> #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) >> +#define pte_user(pte) (!!(pte_val(pte) & PTE_USER)) >> #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) >> #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) >> #define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) >> @@ -312,7 +314,7 @@ static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep, >> __func__, pte_val(old_pte), pte_val(pte)); >> } >> >> -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, >> +static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, >> pte_t *ptep, pte_t pte) > > A small nit. Subsequent line containing the arguments "pte_t *ptep ..." > needs to be aligned properly, after '__' got added into set_pte_at().
OK, missing that, .will fix it next version.
> >> { >> if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte)) >> @@ -343,6 +345,13 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, >> set_pte(ptep, pte); >> } >> >> +static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, >> + pte_t *ptep, pte_t pte) >> +{ >> + page_table_check_pte_set(mm, addr, ptep, pte); >> + return __set_pte_at(mm, addr, ptep, pte); >> +} >> + >> /* >> * Huge pte definitions. >> */ >> @@ -454,6 +463,8 @@ static inline int pmd_trans_huge(pmd_t pmd) >> #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) >> #define pmd_young(pmd) pte_young(pmd_pte(pmd)) >> #define pmd_valid(pmd) pte_valid(pmd_pte(pmd)) >> +#define pmd_user(pmd) pte_user(pmd_pte(pmd)) >> +#define pmd_user_exec(pmd) pte_user_exec(pmd_pte(pmd)) >> #define pmd_cont(pmd) pte_cont(pmd_pte(pmd)) >> #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) >> #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) >> @@ -501,8 +512,19 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) >> #define pud_pfn(pud) ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT) >> #define pfn_pud(pfn,prot) __pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) >> >> -#define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)) >> -#define set_pud_at(mm, addr, pudp, pud) set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud)) >> +static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, >> + pmd_t *pmdp, pmd_t pmd) >> +{ >> + page_table_check_pmd_set(mm, addr, pmdp, pmd); >> + return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)); >> +} >> + >> +static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, >> + pud_t *pudp, pud_t pud) >> +{ >> + page_table_check_pud_set(mm, addr, pudp, pud); >> + return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud)); >> +} >> >> #define __p4d_to_phys(p4d) __pte_to_phys(p4d_pte(p4d)) >> #define __phys_to_p4d_val(phys) __phys_to_pte_val(phys) >> @@ -643,6 +665,24 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) >> #define pud_present(pud) pte_present(pud_pte(pud)) >> #define pud_leaf(pud) pud_sect(pud) >> #define pud_valid(pud) pte_valid(pud_pte(pud)) >> +#define pud_user(pud) pte_user(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) || pte_user_exec(pte)); >> +} >> + >> +static inline bool pmd_user_accessible_page(pmd_t pmd) >> +{ >> + return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> +} >> + >> +static inline bool pud_user_accessible_page(pud_t pud) >> +{ >> + return pud_present(pud) && pud_user(pud); >> +} >> +#endif >> >> static inline void set_pud(pud_t *pudp, pud_t pud) >> { >> @@ -876,7 +916,11 @@ static inline int pmdp_test_and_clear_young(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(xchg_relaxed(&pte_val(*ptep), 0)); >> + pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); >> + >> + page_table_check_pte_clear(mm, address, pte); >> + >> + return pte; >> } >> >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE >> @@ -884,7 +928,11 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, >> 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(__pte(xchg_relaxed(&pte_val(*(pte_t *)pmdp), 0))); > > Why there is any change here ? Why not just the following instead, like what you did > in ptep_get_and_clear() above. The page table entry return value here just needs to > be preserved for subsequent page table check helpers. > > pmd_t pmd = pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp)); >
Hi Anshuman: The purpose of what I do here is to avoid doing page_table_check_pte_clear() in ptep_get_and_clear(). there is no functional change here.
Thanks, Tong.
>> + >> + page_table_check_pmd_clear(mm, address, pmd); >> + >> + return pmd; >> } >> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >> >> @@ -918,6 +966,7 @@ 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(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd))); >> } >> #endif > .
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