diff options
| -rw-r--r-- | include/linux/swapops.h | 3 | ||||
| -rw-r--r-- | include/linux/userfaultfd_k.h | 47 | ||||
| -rw-r--r-- | mm/Kconfig | 9 |
3 files changed, 58 insertions, 1 deletions
diff --git a/include/linux/swapops.h b/include/linux/swapops.h index bb70da461b7d..09945342bf76 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -276,7 +276,8 @@ static inline int is_readable_migration_entry(swp_entry_t entry) typedef unsigned long pte_marker; -#define PTE_MARKER_MASK (0) +#define PTE_MARKER_UFFD_WP BIT(0) +#define PTE_MARKER_MASK (PTE_MARKER_UFFD_WP) #ifdef CONFIG_PTE_MARKER diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 33cea484d1ad..3354d9ddc35f 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -15,6 +15,8 @@ #include <linux/fcntl.h> #include <linux/mm.h> +#include <linux/swap.h> +#include <linux/swapops.h> #include <asm-generic/pgtable_uffd.h> /* The set of all possible UFFD-related VM flags. */ @@ -236,4 +238,49 @@ static inline void userfaultfd_unmap_complete(struct mm_struct *mm, #endif /* CONFIG_USERFAULTFD */ +static inline bool pte_marker_entry_uffd_wp(swp_entry_t entry) +{ +#ifdef CONFIG_PTE_MARKER_UFFD_WP + return is_pte_marker_entry(entry) && + (pte_marker_get(entry) & PTE_MARKER_UFFD_WP); +#else + return false; +#endif +} + +static inline bool pte_marker_uffd_wp(pte_t pte) +{ +#ifdef CONFIG_PTE_MARKER_UFFD_WP + swp_entry_t entry; + + if (!is_swap_pte(pte)) + return false; + + entry = pte_to_swp_entry(pte); + + return pte_marker_entry_uffd_wp(entry); +#else + return false; +#endif +} + +/* + * Returns true if this is a swap pte and was uffd-wp wr-protected in either + * forms (pte marker or a normal swap pte), false otherwise. + */ +static inline bool pte_swp_uffd_wp_any(pte_t pte) +{ +#ifdef CONFIG_PTE_MARKER_UFFD_WP + if (!is_swap_pte(pte)) + return false; + + if (pte_swp_uffd_wp(pte)) + return true; + + if (pte_marker_uffd_wp(pte)) + return true; +#endif + return false; +} + #endif /* _LINUX_USERFAULTFD_K_H */ diff --git a/mm/Kconfig b/mm/Kconfig index 2262f211b53e..71c653260a44 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -915,6 +915,15 @@ config PTE_MARKER help Allows to create marker PTEs for file-backed memory. +config PTE_MARKER_UFFD_WP + bool "Marker PTEs support for userfaultfd write protection" + depends on PTE_MARKER && HAVE_ARCH_USERFAULTFD_WP + + help + Allows to create marker PTEs for userfaultfd write protection + purposes. It is required to enable userfaultfd write protection on + file-backed memory types like shmem and hugetlbfs. + source "mm/damon/Kconfig" endmenu |