diff options
| -rw-r--r-- | include/linux/mm_inline.h | 11 | ||||
| -rw-r--r-- | mm/memory.c | 16 |
2 files changed, 19 insertions, 8 deletions
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h index 1b6a917fffa4..34e5097182a0 100644 --- a/include/linux/mm_inline.h +++ b/include/linux/mm_inline.h @@ -564,9 +564,9 @@ static inline pte_marker copy_pte_marker( * Must be called with pgtable lock held so that no thread will see the none * pte, and if they see it, they'll fault and serialize at the pgtable lock. * - * This function is a no-op if PTE_MARKER_UFFD_WP is not enabled. + * Returns true if an uffd-wp pte was installed, false otherwise. */ -static inline void +static inline bool pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, pte_t pteval) { @@ -583,7 +583,7 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, * with a swap pte. There's no way of leaking the bit. */ if (vma_is_anonymous(vma) || !userfaultfd_wp(vma)) - return; + return false; /* A uffd-wp wr-protected normal pte */ if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval))) @@ -596,10 +596,13 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, if (unlikely(pte_swp_uffd_wp_any(pteval))) arm_uffd_pte = true; - if (unlikely(arm_uffd_pte)) + if (unlikely(arm_uffd_pte)) { set_pte_at(vma->vm_mm, addr, pte, make_pte_marker(PTE_MARKER_UFFD_WP)); + return true; + } #endif + return false; } static inline bool vma_has_recency(struct vm_area_struct *vma) diff --git a/mm/memory.c b/mm/memory.c index 576eb9c4b57c..67406cb662ea 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1466,27 +1466,35 @@ static inline bool zap_drop_markers(struct zap_details *details) /* * This function makes sure that we'll replace the none pte with an uffd-wp * swap special pte marker when necessary. Must be with the pgtable lock held. + * + * Returns true if uffd-wp ptes was installed, false otherwise. */ -static inline void +static inline bool zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, int nr, struct zap_details *details, pte_t pteval) { + bool was_installed = false; + +#ifdef CONFIG_PTE_MARKER_UFFD_WP /* Zap on anonymous always means dropping everything */ if (vma_is_anonymous(vma)) - return; + return false; if (zap_drop_markers(details)) - return; + return false; for (;;) { /* the PFN in the PTE is irrelevant. */ - pte_install_uffd_wp_if_needed(vma, addr, pte, pteval); + if (pte_install_uffd_wp_if_needed(vma, addr, pte, pteval)) + was_installed = true; if (--nr == 0) break; pte++; addr += PAGE_SIZE; } +#endif + return was_installed; } static __always_inline void zap_present_folio_ptes(struct mmu_gather *tlb, |