@@ -597,6 +597,8 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page,
 
 		entry = mk_huge_pmd(page, vma->vm_page_prot);
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+		if (is_shstk_mapping(vma->vm_flags))
+			entry = pmd_mkdirty_shstk(entry);
 		page_add_new_anon_rmap(page, vma, haddr, true);
 		mem_cgroup_commit_charge(page, memcg, false, true);
 		lru_cache_add_active_or_unevictable(page, vma);

@@ -1193,6 +1195,8 @@ static int do_huge_pmd_wp_page_fallback(struct vm_fault *vmf, pmd_t orig_pmd,
 		pte_t entry;
 		entry = mk_pte(pages[i], vma->vm_page_prot);
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+		if (is_shstk_mapping(vma->vm_flags))
+			entry = pte_mkdirty_shstk(entry);
 		memcg = (void *)page_private(pages[i]);
 		set_page_private(pages[i], 0);
 		page_add_new_anon_rmap(pages[i], vmf->vma, haddr, false);

@@ -1277,6 +1281,8 @@ int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 		pmd_t entry;
 		entry = pmd_mkyoung(orig_pmd);
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+		if (is_shstk_mapping(vma->vm_flags))
+			entry = pmd_mkdirty_shstk(entry);
 		if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry,  1))
 			update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
 		ret |= VM_FAULT_WRITE;

@@ -1347,6 +1353,8 @@ int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 		pmd_t entry;
 		entry = mk_huge_pmd(new_page, vma->vm_page_prot);
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+		if (is_shstk_mapping(vma->vm_flags))
+			entry = pmd_mkdirty_shstk(entry);
 		pmdp_huge_clear_flush_notify(vma, haddr, vmf->pmd);
 		page_add_new_anon_rmap(new_page, vma, haddr, true);
 		mem_cgroup_commit_charge(new_page, memcg, false, true);

@@ -4108,7 +4108,13 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 			if (pmd_protnone(orig_pmd) && vma_is_accessible(vma))
 				return do_huge_pmd_numa_page(&vmf, orig_pmd);
 
-			if (dirty && !pmd_write(orig_pmd)) {
+			/*
+			 * Shadow stack trans huge PMDs are copy-on-access,
+			 * so wp_huge_pmd() on them no mater if we have a
+			 * write fault or not.
+			 */
+			if (is_shstk_mapping(vma->vm_flags) ||
+			    (dirty && !pmd_write(orig_pmd))) {
 				ret = wp_huge_pmd(&vmf, orig_pmd);
 				if (!(ret & VM_FAULT_FALLBACK))
 					return ret;