1 files changed, 71 insertions, 35 deletions

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index bff1e8d97de0..96f26e29fefe 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -334,7 +334,7 @@ static inline bool is_migration_entry_dirty(swp_entry_t entry)
 
 extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 					unsigned long address);
-extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
+extern void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *pte);
 #else  /* CONFIG_MIGRATION */
 static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
 {
@@ -359,7 +359,7 @@ static inline int is_migration_entry(swp_entry_t swp)
 static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 					unsigned long address) { }
 static inline void migration_entry_wait_huge(struct vm_area_struct *vma,
-					pte_t *pte) { }
+					     unsigned long addr, pte_t *pte) { }
 static inline int is_writable_migration_entry(swp_entry_t entry)
 {
 	return 0;
@@ -390,6 +390,35 @@ static inline bool is_migration_entry_dirty(swp_entry_t entry)
 }
 #endif	/* CONFIG_MIGRATION */
 
+#ifdef CONFIG_MEMORY_FAILURE
+
+/*
+ * Support for hardware poisoned pages
+ */
+static inline swp_entry_t make_hwpoison_entry(struct page *page)
+{
+	BUG_ON(!PageLocked(page));
+	return swp_entry(SWP_HWPOISON, page_to_pfn(page));
+}
+
+static inline int is_hwpoison_entry(swp_entry_t entry)
+{
+	return swp_type(entry) == SWP_HWPOISON;
+}
+
+#else
+
+static inline swp_entry_t make_hwpoison_entry(struct page *page)
+{
+	return swp_entry(0, 0);
+}
+
+static inline int is_hwpoison_entry(swp_entry_t swp)
+{
+	return 0;
+}
+#endif
+
 typedef unsigned long pte_marker;
 
 #define  PTE_MARKER_UFFD_WP			BIT(0)
@@ -397,9 +426,19 @@ typedef unsigned long pte_marker;
  * "Poisoned" here is meant in the very general sense of "future accesses are
  * invalid", instead of referring very specifically to hardware memory errors.
  * This marker is meant to represent any of various different causes of this.
+ *
+ * Note that, when encountered by the faulting logic, PTEs with this marker will
+ * result in VM_FAULT_HWPOISON and thus regardless trigger hardware memory error
+ * logic.
  */
 #define  PTE_MARKER_POISONED			BIT(1)
-#define  PTE_MARKER_MASK			(BIT(2) - 1)
+/*
+ * Indicates that, on fault, this PTE will case a SIGSEGV signal to be
+ * sent. This means guard markers behave in effect as if the region were mapped
+ * PROT_NONE, rather than if they were a memory hole or equivalent.
+ */
+#define  PTE_MARKER_GUARD			BIT(2)
+#define  PTE_MARKER_MASK			(BIT(3) - 1)
 
 static inline swp_entry_t make_pte_marker_entry(pte_marker marker)
 {
@@ -435,6 +474,18 @@ static inline int is_poisoned_swp_entry(swp_entry_t entry)
 {
 	return is_pte_marker_entry(entry) &&
 	    (pte_marker_get(entry) & PTE_MARKER_POISONED);
+
+}
+
+static inline swp_entry_t make_guard_swp_entry(void)
+{
+	return make_pte_marker_entry(PTE_MARKER_GUARD);
+}
+
+static inline int is_guard_swp_entry(swp_entry_t entry)
+{
+	return is_pte_marker_entry(entry) &&
+		(pte_marker_get(entry) & PTE_MARKER_GUARD);
 }
 
 /*
@@ -468,10 +519,24 @@ static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry)
 	return p;
 }
 
+static inline struct folio *pfn_swap_entry_folio(swp_entry_t entry)
+{
+	struct folio *folio = pfn_folio(swp_offset_pfn(entry));
+
+	/*
+	 * Any use of migration entries may only occur while the
+	 * corresponding folio is locked
+	 */
+	BUG_ON(is_migration_entry(entry) && !folio_test_locked(folio));
+
+	return folio;
+}
+
 /*
  * A pfn swap entry is a special type of swap entry that always has a pfn stored
- * in the swap offset. They are used to represent unaddressable device memory
- * and to restrict access to a page undergoing migration.
+ * in the swap offset. They can either be used to represent unaddressable device
+ * memory, to restrict access to a page undergoing migration or to represent a
+ * pfn which has been hwpoisoned and unmapped.
  */
 static inline bool is_pfn_swap_entry(swp_entry_t entry)
 {
@@ -479,7 +544,7 @@ static inline bool is_pfn_swap_entry(swp_entry_t entry)
 	BUILD_BUG_ON(SWP_TYPE_SHIFT < SWP_PFN_BITS);
 
 	return is_migration_entry(entry) || is_device_private_entry(entry) ||
-	       is_device_exclusive_entry(entry);
+	       is_device_exclusive_entry(entry) || is_hwpoison_entry(entry);
 }
 
 struct page_vma_mapped_walk;
@@ -548,35 +613,6 @@ static inline int is_pmd_migration_entry(pmd_t pmd)
 }
 #endif  /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
 
-#ifdef CONFIG_MEMORY_FAILURE
-
-/*
- * Support for hardware poisoned pages
- */
-static inline swp_entry_t make_hwpoison_entry(struct page *page)
-{
-	BUG_ON(!PageLocked(page));
-	return swp_entry(SWP_HWPOISON, page_to_pfn(page));
-}
-
-static inline int is_hwpoison_entry(swp_entry_t entry)
-{
-	return swp_type(entry) == SWP_HWPOISON;
-}
-
-#else
-
-static inline swp_entry_t make_hwpoison_entry(struct page *page)
-{
-	return swp_entry(0, 0);
-}
-
-static inline int is_hwpoison_entry(swp_entry_t swp)
-{
-	return 0;
-}
-#endif
-
 static inline int non_swap_entry(swp_entry_t entry)
 {
 	return swp_type(entry) >= MAX_SWAPFILES;