在 2022/4/29 14:18, Anshuman Khandual 写道:
On 4/26/22 13:40, Tong Tiangen wrote:From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx> Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx> --- 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); +} +#endifstatic 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.
