diff options
Diffstat (limited to 'mm/page_table_check.c')
| -rw-r--r-- | mm/page_table_check.c | 93 |
1 files changed, 61 insertions, 32 deletions
diff --git a/mm/page_table_check.c b/mm/page_table_check.c index af69c3c8f7c2..4eeca782b888 100644 --- a/mm/page_table_check.c +++ b/mm/page_table_check.c @@ -7,6 +7,8 @@ #include <linux/kstrtox.h> #include <linux/mm.h> #include <linux/page_table_check.h> +#include <linux/swap.h> +#include <linux/swapops.h> #undef pr_fmt #define pr_fmt(fmt) "page_table_check: " fmt @@ -60,21 +62,20 @@ static struct page_table_check *get_page_table_check(struct page_ext *page_ext) */ static void page_table_check_clear(unsigned long pfn, unsigned long pgcnt) { + struct page_ext_iter iter; struct page_ext *page_ext; struct page *page; - unsigned long i; bool anon; if (!pfn_valid(pfn)) return; page = pfn_to_page(pfn); - page_ext = page_ext_get(page); - BUG_ON(PageSlab(page)); anon = PageAnon(page); - for (i = 0; i < pgcnt; i++) { + rcu_read_lock(); + for_each_page_ext(page, pgcnt, page_ext, iter) { struct page_table_check *ptc = get_page_table_check(page_ext); if (anon) { @@ -84,9 +85,8 @@ static void page_table_check_clear(unsigned long pfn, unsigned long pgcnt) BUG_ON(atomic_read(&ptc->anon_map_count)); BUG_ON(atomic_dec_return(&ptc->file_map_count) < 0); } - page_ext = page_ext_next(page_ext); } - page_ext_put(page_ext); + rcu_read_unlock(); } /* @@ -97,21 +97,20 @@ static void page_table_check_clear(unsigned long pfn, unsigned long pgcnt) static void page_table_check_set(unsigned long pfn, unsigned long pgcnt, bool rw) { + struct page_ext_iter iter; struct page_ext *page_ext; struct page *page; - unsigned long i; bool anon; if (!pfn_valid(pfn)) return; page = pfn_to_page(pfn); - page_ext = page_ext_get(page); - BUG_ON(PageSlab(page)); anon = PageAnon(page); - for (i = 0; i < pgcnt; i++) { + rcu_read_lock(); + for_each_page_ext(page, pgcnt, page_ext, iter) { struct page_table_check *ptc = get_page_table_check(page_ext); if (anon) { @@ -121,9 +120,8 @@ static void page_table_check_set(unsigned long pfn, unsigned long pgcnt, BUG_ON(atomic_read(&ptc->anon_map_count)); BUG_ON(atomic_inc_return(&ptc->file_map_count) < 0); } - page_ext = page_ext_next(page_ext); } - page_ext_put(page_ext); + rcu_read_unlock(); } /* @@ -132,21 +130,19 @@ static void page_table_check_set(unsigned long pfn, unsigned long pgcnt, */ void __page_table_check_zero(struct page *page, unsigned int order) { + struct page_ext_iter iter; struct page_ext *page_ext; - unsigned long i; BUG_ON(PageSlab(page)); - page_ext = page_ext_get(page); - BUG_ON(!page_ext); - for (i = 0; i < (1ul << order); i++) { + rcu_read_lock(); + for_each_page_ext(page, 1 << order, page_ext, iter) { struct page_table_check *ptc = get_page_table_check(page_ext); BUG_ON(atomic_read(&ptc->anon_map_count)); BUG_ON(atomic_read(&ptc->file_map_count)); - page_ext = page_ext_next(page_ext); } - page_ext_put(page_ext); + rcu_read_unlock(); } void __page_table_check_pte_clear(struct mm_struct *mm, pte_t pte) @@ -182,6 +178,21 @@ void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud) } EXPORT_SYMBOL(__page_table_check_pud_clear); +/* Whether the swap entry cached writable information */ +static inline bool swap_cached_writable(swp_entry_t entry) +{ + return is_writable_device_private_entry(entry) || + is_writable_migration_entry(entry); +} + +static inline void page_table_check_pte_flags(pte_t pte) +{ + if (pte_present(pte) && pte_uffd_wp(pte)) + WARN_ON_ONCE(pte_write(pte)); + else if (is_swap_pte(pte) && pte_swp_uffd_wp(pte)) + WARN_ON_ONCE(swap_cached_writable(pte_to_swp_entry(pte))); +} + void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte, unsigned int nr) { @@ -190,6 +201,8 @@ void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte, if (&init_mm == mm) return; + page_table_check_pte_flags(pte); + for (i = 0; i < nr; i++) __page_table_check_pte_clear(mm, ptep_get(ptep + i)); if (pte_user_accessible_page(pte)) @@ -197,31 +210,47 @@ void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte, } EXPORT_SYMBOL(__page_table_check_ptes_set); -void __page_table_check_pmd_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd) +static inline void page_table_check_pmd_flags(pmd_t pmd) +{ + if (pmd_present(pmd) && pmd_uffd_wp(pmd)) + WARN_ON_ONCE(pmd_write(pmd)); + else if (is_swap_pmd(pmd) && pmd_swp_uffd_wp(pmd)) + WARN_ON_ONCE(swap_cached_writable(pmd_to_swp_entry(pmd))); +} + +void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd, + unsigned int nr) { + unsigned long stride = PMD_SIZE >> PAGE_SHIFT; + unsigned int i; + if (&init_mm == mm) return; - __page_table_check_pmd_clear(mm, *pmdp); - if (pmd_user_accessible_page(pmd)) { - page_table_check_set(pmd_pfn(pmd), PMD_SIZE >> PAGE_SHIFT, - pmd_write(pmd)); - } + page_table_check_pmd_flags(pmd); + + for (i = 0; i < nr; i++) + __page_table_check_pmd_clear(mm, *(pmdp + i)); + if (pmd_user_accessible_page(pmd)) + page_table_check_set(pmd_pfn(pmd), stride * nr, pmd_write(pmd)); } -EXPORT_SYMBOL(__page_table_check_pmd_set); +EXPORT_SYMBOL(__page_table_check_pmds_set); -void __page_table_check_pud_set(struct mm_struct *mm, pud_t *pudp, pud_t pud) +void __page_table_check_puds_set(struct mm_struct *mm, pud_t *pudp, pud_t pud, + unsigned int nr) { + unsigned long stride = PUD_SIZE >> PAGE_SHIFT; + unsigned int i; + if (&init_mm == mm) return; - __page_table_check_pud_clear(mm, *pudp); - if (pud_user_accessible_page(pud)) { - page_table_check_set(pud_pfn(pud), PUD_SIZE >> PAGE_SHIFT, - pud_write(pud)); - } + for (i = 0; i < nr; i++) + __page_table_check_pud_clear(mm, *(pudp + i)); + if (pud_user_accessible_page(pud)) + page_table_check_set(pud_pfn(pud), stride * nr, pud_write(pud)); } -EXPORT_SYMBOL(__page_table_check_pud_set); +EXPORT_SYMBOL(__page_table_check_puds_set); void __page_table_check_pte_clear_range(struct mm_struct *mm, unsigned long addr, |