}
#endif
+static void restore_exclusive_pte(struct vm_area_struct *vma,
+ struct page *page, unsigned long address,
+ pte_t *ptep)
+{
+ pte_t pte;
+ swp_entry_t entry;
+
+ pte = pte_mkold(mk_pte(page, READ_ONCE(vma->vm_page_prot)));
+ if (pte_swp_soft_dirty(*ptep))
+ pte = pte_mksoft_dirty(pte);
+
+ entry = pte_to_swp_entry(*ptep);
+ if (pte_swp_uffd_wp(*ptep))
+ pte = pte_mkuffd_wp(pte);
+ else if (is_writable_device_exclusive_entry(entry))
+ pte = maybe_mkwrite(pte_mkdirty(pte), vma);
+
+ set_pte_at(vma->vm_mm, address, ptep, pte);
+
+ /*
+ * No need to take a page reference as one was already
+ * created when the swap entry was made.
+ */
+ if (PageAnon(page))
+ page_add_anon_rmap(page, vma, address, false);
+ else
+ /*
+ * Currently device exclusive access only supports anonymous
+ * memory so the entry shouldn't point to a filebacked page.
+ */
+ WARN_ON_ONCE(!PageAnon(page));
+
+ if (vma->vm_flags & VM_LOCKED)
+ mlock_vma_page(page);
+
+ /*
+ * No need to invalidate - it was non-present before. However
+ * secondary CPUs may have mappings that need invalidating.
+ */
+ update_mmu_cache(vma, address, ptep);
+}
+
+/*
+ * Tries to restore an exclusive pte if the page lock can be acquired without
+ * sleeping.
+ */
+static int
+try_restore_exclusive_pte(pte_t *src_pte, struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ swp_entry_t entry = pte_to_swp_entry(*src_pte);
+ struct page *page = pfn_swap_entry_to_page(entry);
+
+ if (trylock_page(page)) {
+ restore_exclusive_pte(vma, page, addr, src_pte);
+ unlock_page(page);
+ return 0;
+ }
+
+ return -EBUSY;
+}
+
/*
* copy one vm_area from one task to the other. Assumes the page tables
* already present in the new task to be cleared in the whole range
static unsigned long
copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
- pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
- unsigned long addr, int *rss)
+ pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *dst_vma,
+ struct vm_area_struct *src_vma, unsigned long addr, int *rss)
{
- unsigned long vm_flags = vma->vm_flags;
+ unsigned long vm_flags = dst_vma->vm_flags;
pte_t pte = *src_pte;
struct page *page;
swp_entry_t entry = pte_to_swp_entry(pte);
if (likely(!non_swap_entry(entry))) {
if (swap_duplicate(entry) < 0)
- return entry.val;
+ return -EIO;
/* make sure dst_mm is on swapoff's mmlist. */
if (unlikely(list_empty(&dst_mm->mmlist))) {
}
rss[MM_SWAPENTS]++;
} else if (is_migration_entry(entry)) {
- page = migration_entry_to_page(entry);
+ page = pfn_swap_entry_to_page(entry);
rss[mm_counter(page)]++;
- if (is_write_migration_entry(entry) &&
+ if (is_writable_migration_entry(entry) &&
is_cow_mapping(vm_flags)) {
/*
* COW mappings require pages in both
* parent and child to be set to read.
*/
- make_migration_entry_read(&entry);
+ entry = make_readable_migration_entry(
+ swp_offset(entry));
pte = swp_entry_to_pte(entry);
if (pte_swp_soft_dirty(*src_pte))
pte = pte_swp_mksoft_dirty(pte);
set_pte_at(src_mm, addr, src_pte, pte);
}
} else if (is_device_private_entry(entry)) {
- page = device_private_entry_to_page(entry);
+ page = pfn_swap_entry_to_page(entry);
/*
* Update rss count even for unaddressable pages, as
* when a device driver is involved (you cannot easily
* save and restore device driver state).
*/
- if (is_write_device_private_entry(entry) &&
+ if (is_writable_device_private_entry(entry) &&
is_cow_mapping(vm_flags)) {
- make_device_private_entry_read(&entry);
+ entry = make_readable_device_private_entry(
+ swp_offset(entry));
pte = swp_entry_to_pte(entry);
if (pte_swp_uffd_wp(*src_pte))
pte = pte_swp_mkuffd_wp(pte);
set_pte_at(src_mm, addr, src_pte, pte);
}
+ } else if (is_device_exclusive_entry(entry)) {
+ /*
+ * Make device exclusive entries present by restoring the
+ * original entry then copying as for a present pte. Device
+ * exclusive entries currently only support private writable
+ * (ie. COW) mappings.
+ */
+ VM_BUG_ON(!is_cow_mapping(src_vma->vm_flags));
+ if (try_restore_exclusive_pte(src_pte, src_vma, addr))
+ return -EBUSY;
+ return -ENOENT;
}
+ if (!userfaultfd_wp(dst_vma))
+ pte = pte_swp_clear_uffd_wp(pte);
set_pte_at(dst_mm, addr, dst_pte, pte);
return 0;
}
/* All done, just insert the new page copy in the child */
pte = mk_pte(new_page, dst_vma->vm_page_prot);
pte = maybe_mkwrite(pte_mkdirty(pte), dst_vma);
+ if (userfaultfd_pte_wp(dst_vma, *src_pte))
+ /* Uffd-wp needs to be delivered to dest pte as well */
+ pte = pte_wrprotect(pte_mkuffd_wp(pte));
set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
return 0;
}
pte = pte_mkclean(pte);
pte = pte_mkold(pte);
- /*
- * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA
- * does not have the VM_UFFD_WP, which means that the uffd
- * fork event is not enabled.
- */
- if (!(vm_flags & VM_UFFD_WP))
+ if (!userfaultfd_wp(dst_vma))
pte = pte_clear_uffd_wp(pte);
set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
continue;
}
if (unlikely(!pte_present(*src_pte))) {
- entry.val = copy_nonpresent_pte(dst_mm, src_mm,
- dst_pte, src_pte,
- src_vma, addr, rss);
- if (entry.val)
+ ret = copy_nonpresent_pte(dst_mm, src_mm,
+ dst_pte, src_pte,
+ dst_vma, src_vma,
+ addr, rss);
+ if (ret == -EIO) {
+ entry = pte_to_swp_entry(*src_pte);
break;
- progress += 8;
- continue;
+ } else if (ret == -EBUSY) {
+ break;
+ } else if (!ret) {
+ progress += 8;
+ continue;
+ }
+
+ /*
+ * Device exclusive entry restored, continue by copying
+ * the now present pte.
+ */
+ WARN_ON_ONCE(ret != -ENOENT);
}
/* copy_present_pte() will clear `*prealloc' if consumed */
ret = copy_present_pte(dst_vma, src_vma, dst_pte, src_pte,
pte_unmap_unlock(orig_dst_pte, dst_ptl);
cond_resched();
- if (entry.val) {
+ if (ret == -EIO) {
+ VM_WARN_ON_ONCE(!entry.val);
if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) {
ret = -ENOMEM;
goto out;
}
entry.val = 0;
- } else if (ret) {
- WARN_ON_ONCE(ret != -EAGAIN);
+ } else if (ret == -EBUSY) {
+ goto out;
+ } else if (ret == -EAGAIN) {
prealloc = page_copy_prealloc(src_mm, src_vma, addr);
if (!prealloc)
return -ENOMEM;
- /* We've captured and resolved the error. Reset, try again. */
- ret = 0;
+ } else if (ret) {
+ VM_WARN_ON_ONCE(1);
}
+
+ /* We've captured and resolved the error. Reset, try again. */
+ ret = 0;
+
if (addr != end)
goto again;
out:
|| pmd_devmap(*src_pmd)) {
int err;
VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, src_vma);
- err = copy_huge_pmd(dst_mm, src_mm,
- dst_pmd, src_pmd, addr, src_vma);
+ err = copy_huge_pmd(dst_mm, src_mm, dst_pmd, src_pmd,
+ addr, dst_vma, src_vma);
if (err == -ENOMEM)
return -ENOMEM;
if (!err)
}
entry = pte_to_swp_entry(ptent);
- if (is_device_private_entry(entry)) {
- struct page *page = device_private_entry_to_page(entry);
+ if (is_device_private_entry(entry) ||
+ is_device_exclusive_entry(entry)) {
+ struct page *page = pfn_swap_entry_to_page(entry);
if (unlikely(details && details->check_mapping)) {
/*
pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
rss[mm_counter(page)]--;
- page_remove_rmap(page, false);
+
+ if (is_device_private_entry(entry))
+ page_remove_rmap(page, false);
+
put_page(page);
continue;
}
else if (is_migration_entry(entry)) {
struct page *page;
- page = migration_entry_to_page(entry);
+ page = pfn_swap_entry_to_page(entry);
rss[mm_counter(page)]--;
}
if (unlikely(!free_swap_and_cache(entry)))
}
EXPORT_SYMBOL(unmap_mapping_range);
+/*
+ * Restore a potential device exclusive pte to a working pte entry
+ */
+static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf)
+{
+ struct page *page = vmf->page;
+ struct vm_area_struct *vma = vmf->vma;
+ struct mmu_notifier_range range;
+
+ if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags))
+ return VM_FAULT_RETRY;
+ mmu_notifier_range_init_owner(&range, MMU_NOTIFY_EXCLUSIVE, 0, vma,
+ vma->vm_mm, vmf->address & PAGE_MASK,
+ (vmf->address & PAGE_MASK) + PAGE_SIZE, NULL);
+ mmu_notifier_invalidate_range_start(&range);
+
+ vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
+ &vmf->ptl);
+ if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
+ restore_exclusive_pte(vma, page, vmf->address, vmf->pte);
+
+ pte_unmap_unlock(vmf->pte, vmf->ptl);
+ unlock_page(page);
+
+ mmu_notifier_invalidate_range_end(&range);
+ return 0;
+}
+
/*
* We enter with non-exclusive mmap_lock (to exclude vma changes,
* but allow concurrent faults), and pte mapped but not yet locked.
if (is_migration_entry(entry)) {
migration_entry_wait(vma->vm_mm, vmf->pmd,
vmf->address);
+ } else if (is_device_exclusive_entry(entry)) {
+ vmf->page = pfn_swap_entry_to_page(entry);
+ ret = remove_device_exclusive_entry(vmf);
} else if (is_device_private_entry(entry)) {
- vmf->page = device_private_entry_to_page(entry);
+ vmf->page = pfn_swap_entry_to_page(entry);
ret = vmf->page->pgmap->ops->migrate_to_ram(vmf);
} else if (is_hwpoison_entry(entry)) {
ret = VM_FAULT_HWPOISON;
* something).
*/
if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) {
- ret = do_fault_around(vmf);
- if (ret)
- return ret;
+ if (likely(!userfaultfd_minor(vmf->vma))) {
+ ret = do_fault_around(vmf);
+ if (ret)
+ return ret;
+ }
}
ret = __do_fault(vmf);
return ret;
}
-static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
- unsigned long addr, int page_nid,
- int *flags)
+int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+ unsigned long addr, int page_nid, int *flags)
{
get_page(page);
}
/* `inline' is required to avoid gcc 4.1.2 build error */
-static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
+static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf)
{
if (vma_is_anonymous(vmf->vma)) {
- if (userfaultfd_huge_pmd_wp(vmf->vma, orig_pmd))
+ if (userfaultfd_huge_pmd_wp(vmf->vma, vmf->orig_pmd))
return handle_userfault(vmf, VM_UFFD_WP);
- return do_huge_pmd_wp_page(vmf, orig_pmd);
+ return do_huge_pmd_wp_page(vmf);
}
if (vmf->vma->vm_ops->huge_fault) {
vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
} else {
- pmd_t orig_pmd = *vmf.pmd;
+ vmf.orig_pmd = *vmf.pmd;
barrier();
- if (unlikely(is_swap_pmd(orig_pmd))) {
+ if (unlikely(is_swap_pmd(vmf.orig_pmd))) {
VM_BUG_ON(thp_migration_supported() &&
- !is_pmd_migration_entry(orig_pmd));
- if (is_pmd_migration_entry(orig_pmd))
+ !is_pmd_migration_entry(vmf.orig_pmd));
+ if (is_pmd_migration_entry(vmf.orig_pmd))
pmd_migration_entry_wait(mm, vmf.pmd);
return 0;
}
- if (pmd_trans_huge(orig_pmd) || pmd_devmap(orig_pmd)) {
- if (pmd_protnone(orig_pmd) && vma_is_accessible(vma))
- return do_huge_pmd_numa_page(&vmf, orig_pmd);
+ if (pmd_trans_huge(vmf.orig_pmd) || pmd_devmap(vmf.orig_pmd)) {
+ if (pmd_protnone(vmf.orig_pmd) && vma_is_accessible(vma))
+ return do_huge_pmd_numa_page(&vmf);
- if (dirty && !pmd_write(orig_pmd)) {
- ret = wp_huge_pmd(&vmf, orig_pmd);
+ if (dirty && !pmd_write(vmf.orig_pmd)) {
+ ret = wp_huge_pmd(&vmf);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
} else {
- huge_pmd_set_accessed(&vmf, orig_pmd);
+ huge_pmd_set_accessed(&vmf);
return 0;
}
}
projects / linux-2.6-microblaze.git / blobdiff