diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 56 |
1 files changed, 42 insertions, 14 deletions
diff --git a/mm/memory.c b/mm/memory.c index 6285cad1f4fb..a890b2951b53 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -104,6 +104,20 @@ EXPORT_SYMBOL(mem_map); #endif static vm_fault_t do_fault(struct vm_fault *vmf); +static vm_fault_t do_anonymous_page(struct vm_fault *vmf); +static bool vmf_pte_changed(struct vm_fault *vmf); + +/* + * Return true if the original pte was a uffd-wp pte marker (so the pte was + * wr-protected). + */ +static bool vmf_orig_pte_uffd_wp(struct vm_fault *vmf) +{ + if (!(vmf->flags & FAULT_FLAG_ORIG_PTE_VALID)) + return false; + + return pte_marker_uffd_wp(vmf->orig_pte); +} /* * A number of key systems in x86 including ioremap() rely on the assumption @@ -1346,6 +1360,10 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, struct zap_details *details, pte_t pteval) { + /* Zap on anonymous always means dropping everything */ + if (vma_is_anonymous(vma)) + return; + if (zap_drop_file_uffd_wp(details)) return; @@ -1452,8 +1470,12 @@ again: continue; rss[mm_counter(page)]--; } else if (pte_marker_entry_uffd_wp(entry)) { - /* Only drop the uffd-wp marker if explicitly requested */ - if (!zap_drop_file_uffd_wp(details)) + /* + * For anon: always drop the marker; for file: only + * drop the marker if explicitly requested. + */ + if (!vma_is_anonymous(vma) && + !zap_drop_file_uffd_wp(details)) continue; } else if (is_hwpoison_entry(entry) || is_swapin_error_entry(entry)) { @@ -3620,6 +3642,14 @@ static vm_fault_t pte_marker_clear(struct vm_fault *vmf) return 0; } +static vm_fault_t do_pte_missing(struct vm_fault *vmf) +{ + if (vma_is_anonymous(vmf->vma)) + return do_anonymous_page(vmf); + else + return do_fault(vmf); +} + /* * This is actually a page-missing access, but with uffd-wp special pte * installed. It means this pte was wr-protected before being unmapped. @@ -3630,11 +3660,10 @@ static vm_fault_t pte_marker_handle_uffd_wp(struct vm_fault *vmf) * Just in case there're leftover special ptes even after the region * got unregistered - we can simply clear them. */ - if (unlikely(!userfaultfd_wp(vmf->vma) || vma_is_anonymous(vmf->vma))) + if (unlikely(!userfaultfd_wp(vmf->vma))) return pte_marker_clear(vmf); - /* do_fault() can handle pte markers too like none pte */ - return do_fault(vmf); + return do_pte_missing(vmf); } static vm_fault_t handle_pte_marker(struct vm_fault *vmf) @@ -3999,6 +4028,7 @@ out_release: */ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) { + bool uffd_wp = vmf_orig_pte_uffd_wp(vmf); struct vm_area_struct *vma = vmf->vma; struct folio *folio; vm_fault_t ret = 0; @@ -4032,7 +4062,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) vma->vm_page_prot)); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_none(*vmf->pte)) { + if (vmf_pte_changed(vmf)) { update_mmu_tlb(vma, vmf->address, vmf->pte); goto unlock; } @@ -4072,7 +4102,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_none(*vmf->pte)) { + if (vmf_pte_changed(vmf)) { update_mmu_tlb(vma, vmf->address, vmf->pte); goto release; } @@ -4092,6 +4122,8 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) folio_add_new_anon_rmap(folio, vma, vmf->address); folio_add_lru_vma(folio, vma); setpte: + if (uffd_wp) + entry = pte_mkuffd_wp(entry); set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); /* No need to invalidate - it was non-present before */ @@ -4259,7 +4291,7 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr) { struct vm_area_struct *vma = vmf->vma; - bool uffd_wp = pte_marker_uffd_wp(vmf->orig_pte); + bool uffd_wp = vmf_orig_pte_uffd_wp(vmf); bool write = vmf->flags & FAULT_FLAG_WRITE; bool prefault = vmf->address != addr; pte_t entry; @@ -4903,12 +4935,8 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) } } - if (!vmf->pte) { - if (vma_is_anonymous(vmf->vma)) - return do_anonymous_page(vmf); - else - return do_fault(vmf); - } + if (!vmf->pte) + return do_pte_missing(vmf); if (!pte_present(vmf->orig_pte)) return do_swap_page(vmf); |