[PATCH 3/8] mm: Return the address from page_mapped_in_vma()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

The only user of this function calls page_address_in_vma() immediately
after page_mapped_in_vma() calculates it and uses it to return true/false.
Return the address instead, allowing memory-failure to skip the call
to page_address_in_vma().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/rmap.h |  2 +-
 mm/memory-failure.c  | 22 ++++++++++++++--------
 mm/page_vma_mapped.c | 14 +++++++-------
 3 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index b7944a833668..ba027a4d9abf 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -698,7 +698,7 @@ int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff,
 
 void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked);
 
-int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 
 /*
  * rmap_walk_control: To control rmap traversing for specific needs
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 7f8473c08ae3..40a8964954e5 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -462,10 +462,11 @@ static void __add_to_kill(struct task_struct *tsk, struct page *p,
 }
 
 static void add_to_kill_anon_file(struct task_struct *tsk, struct page *p,
-				  struct vm_area_struct *vma,
-				  struct list_head *to_kill)
+		struct vm_area_struct *vma, struct list_head *to_kill,
+		unsigned long addr)
 {
-	unsigned long addr = page_address_in_vma(p, vma);
+	if (addr == -EFAULT)
+		return;
 	__add_to_kill(tsk, p, vma, to_kill, addr);
 }
 
@@ -609,12 +610,13 @@ static void collect_procs_anon(struct folio *folio, struct page *page,
 			continue;
 		anon_vma_interval_tree_foreach(vmac, &av->rb_root,
 					       pgoff, pgoff) {
+			unsigned long addr;
+
 			vma = vmac->vma;
 			if (vma->vm_mm != t->mm)
 				continue;
-			if (!page_mapped_in_vma(page, vma))
-				continue;
-			add_to_kill_anon_file(t, page, vma, to_kill);
+			addr = page_mapped_in_vma(page, vma);
+			add_to_kill_anon_file(t, page, vma, to_kill, addr);
 		}
 	}
 	rcu_read_unlock();
@@ -642,6 +644,8 @@ static void collect_procs_file(struct folio *folio, struct page *page,
 			continue;
 		vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
 				      pgoff) {
+			unsigned long addr;
+
 			/*
 			 * Send early kill signal to tasks where a vma covers
 			 * the page but the corrupted page is not necessarily
@@ -649,8 +653,10 @@ static void collect_procs_file(struct folio *folio, struct page *page,
 			 * Assume applications who requested early kill want
 			 * to be informed of all such data corruptions.
 			 */
-			if (vma->vm_mm == t->mm)
-				add_to_kill_anon_file(t, page, vma, to_kill);
+			if (vma->vm_mm != t->mm)
+				continue;
+			addr = page_address_in_vma(page, vma);
+			add_to_kill_anon_file(t, page, vma, to_kill, addr);
 		}
 	}
 	rcu_read_unlock();
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 74d2de15fb5e..e9e208b4ac4b 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -319,11 +319,11 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
  * @page: the page to test
  * @vma: the VMA to test
  *
- * Returns 1 if the page is mapped into the page tables of the VMA, 0
- * if the page is not mapped into the page tables of this VMA.  Only
- * valid for normal file or anonymous VMAs.
+ * Return: If the page is mapped into the page tables of the VMA, the
+ * address that the page is mapped at.  -EFAULT if the page is not mapped.
+ * Only valid for normal file or anonymous VMAs.
  */
-int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
+unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
 {
 	struct page_vma_mapped_walk pvmw = {
 		.pfn = page_to_pfn(page),
@@ -334,9 +334,9 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
 
 	pvmw.address = vma_address(page, vma);
 	if (pvmw.address == -EFAULT)
-		return 0;
+		return -EFAULT;
 	if (!page_vma_mapped_walk(&pvmw))
-		return 0;
+		return -EFAULT;
 	page_vma_mapped_walk_done(&pvmw);
-	return 1;
+	return pvmw.address;
 }
-- 
2.43.0