1 files changed, 29 insertions, 10 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1cc4a5f4791e..ffbea56a8711 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1035,6 +1035,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 	unsigned long pfn = pmd_pfn(*pmd);
 	struct mm_struct *mm = vma->vm_mm;
 	struct page *page;
+	int ret;
 
 	assert_spin_locked(pmd_lockptr(mm, pmd));
 
@@ -1066,8 +1067,9 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 	if (!*pgmap)
 		return ERR_PTR(-EFAULT);
 	page = pfn_to_page(pfn);
-	if (!try_grab_page(page, flags))
-		page = ERR_PTR(-ENOMEM);
+	ret = try_grab_page(page, flags);
+	if (ret)
+		page = ERR_PTR(ret);
 
 	return page;
 }
@@ -1193,6 +1195,7 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 	unsigned long pfn = pud_pfn(*pud);
 	struct mm_struct *mm = vma->vm_mm;
 	struct page *page;
+	int ret;
 
 	assert_spin_locked(pud_lockptr(mm, pud));
 
@@ -1226,8 +1229,10 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 	if (!*pgmap)
 		return ERR_PTR(-EFAULT);
 	page = pfn_to_page(pfn);
-	if (!try_grab_page(page, flags))
-		page = ERR_PTR(-ENOMEM);
+
+	ret = try_grab_page(page, flags);
+	if (ret)
+		page = ERR_PTR(ret);
 
 	return page;
 }
@@ -1435,6 +1440,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 {
 	struct mm_struct *mm = vma->vm_mm;
 	struct page *page;
+	int ret;
 
 	assert_spin_locked(pmd_lockptr(mm, pmd));
 
@@ -1459,8 +1465,9 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 	VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) &&
 			!PageAnonExclusive(page), page);
 
-	if (!try_grab_page(page, flags))
-		return ERR_PTR(-ENOMEM);
+	ret = try_grab_page(page, flags);
+	if (ret)
+		return ERR_PTR(ret);
 
 	if (flags & FOLL_TOUCH)
 		touch_pmd(vma, addr, pmd, flags & FOLL_WRITE);
@@ -2206,9 +2213,12 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 				entry = pte_wrprotect(entry);
 			if (!young)
 				entry = pte_mkold(entry);
-			/* NOTE: this may set soft-dirty too on some archs */
-			if (dirty)
-				entry = pte_mkdirty(entry);
+			/*
+			 * NOTE: we don't do pte_mkdirty when dirty==true
+			 * because it breaks sparc64 which can sigsegv
+			 * random process.  Need to revisit when we figure
+			 * out what is special with sparc64.
+			 */
 			if (soft_dirty)
 				entry = pte_mksoft_dirty(entry);
 			if (uffd_wp)
@@ -2455,7 +2465,16 @@ static void __split_huge_page_tail(struct page *head, int tail,
 			page_tail);
 	page_tail->mapping = head->mapping;
 	page_tail->index = head->index + tail;
-	page_tail->private = 0;
+
+	/*
+	 * page->private should not be set in tail pages with the exception
+	 * of swap cache pages that store the swp_entry_t in tail pages.
+	 * Fix up and warn once if private is unexpectedly set.
+	 */
+	if (!folio_test_swapcache(page_folio(head))) {
+		VM_WARN_ON_ONCE_PAGE(page_tail->private != 0, page_tail);
+		page_tail->private = 0;
+	}
 
 	/* Page flags must be visible before we make the page non-compound. */
 	smp_wmb();