1 files changed, 165 insertions, 69 deletions

diff --git a/mm/debug.c b/mm/debug.c
index ee533a5ceb79..8d2acf432385 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -36,11 +36,6 @@ const struct trace_print_flags pageflag_names[] = {
 	{0, NULL}
 };
 
-const struct trace_print_flags pagetype_names[] = {
-	__def_pagetype_names,
-	{0, NULL}
-};
-
 const struct trace_print_flags gfpflag_names[] = {
 	__def_gfpflag_names,
 	{0, NULL}
@@ -51,87 +46,123 @@ const struct trace_print_flags vmaflag_names[] = {
 	{0, NULL}
 };
 
-static void __dump_page(struct page *page)
+#define DEF_PAGETYPE_NAME(_name) [PGTY_##_name - 0xf0] =  __stringify(_name)
+
+static const char *page_type_names[] = {
+	DEF_PAGETYPE_NAME(slab),
+	DEF_PAGETYPE_NAME(hugetlb),
+	DEF_PAGETYPE_NAME(offline),
+	DEF_PAGETYPE_NAME(guard),
+	DEF_PAGETYPE_NAME(table),
+	DEF_PAGETYPE_NAME(buddy),
+	DEF_PAGETYPE_NAME(unaccepted),
+};
+
+static const char *page_type_name(unsigned int page_type)
 {
-	struct folio *folio = page_folio(page);
-	struct page *head = &folio->page;
-	struct address_space *mapping;
-	bool compound = PageCompound(page);
-	/*
-	 * Accessing the pageblock without the zone lock. It could change to
-	 * "isolate" again in the meantime, but since we are just dumping the
-	 * state for debugging, it should be fine to accept a bit of
-	 * inaccuracy here due to racing.
-	 */
-	bool page_cma = is_migrate_cma_page(page);
-	int mapcount;
-	char *type = "";
+	unsigned i = (page_type >> 24) - 0xf0;
 
-	if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
-		/*
-		 * Corrupt page, so we cannot call page_mapping. Instead, do a
-		 * safe subset of the steps that page_mapping() does. Caution:
-		 * this will be misleading for tail pages, PageSwapCache pages,
-		 * and potentially other situations. (See the page_mapping()
-		 * implementation for what's missing here.)
-		 */
-		unsigned long tmp = (unsigned long)page->mapping;
-
-		if (tmp & PAGE_MAPPING_ANON)
-			mapping = NULL;
-		else
-			mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
-		head = page;
-		folio = (struct folio *)page;
-		compound = false;
-	} else {
-		mapping = page_mapping(page);
-	}
+	if (i >= ARRAY_SIZE(page_type_names))
+		return "unknown";
+	return page_type_names[i];
+}
 
-	/*
-	 * Avoid VM_BUG_ON() in page_mapcount().
-	 * page->_mapcount space in struct page is used by sl[aou]b pages to
-	 * encode own info.
-	 */
-	mapcount = PageSlab(head) ? 0 : page_mapcount(page);
-
-	pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
-			page, page_ref_count(head), mapcount, mapping,
-			page_to_pgoff(page), page_to_pfn(page));
-	if (compound) {
-		pr_warn("head:%p order:%u entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n",
-				head, compound_order(head),
+static void __dump_folio(struct folio *folio, struct page *page,
+		unsigned long pfn, unsigned long idx)
+{
+	struct address_space *mapping = folio_mapping(folio);
+	int mapcount = atomic_read(&page->_mapcount);
+	char *type = "";
+
+	mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1;
+	pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
+			folio_ref_count(folio), mapcount, mapping,
+			folio->index + idx, pfn);
+	if (folio_test_large(folio)) {
+		pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n",
+				folio_order(folio),
+				folio_mapcount(folio),
 				folio_entire_mapcount(folio),
 				folio_nr_pages_mapped(folio),
 				atomic_read(&folio->_pincount));
 	}
 
 #ifdef CONFIG_MEMCG
-	if (head->memcg_data)
-		pr_warn("memcg:%lx\n", head->memcg_data);
+	if (folio->memcg_data)
+		pr_warn("memcg:%lx\n", folio->memcg_data);
 #endif
-	if (PageKsm(page))
+	if (folio_test_ksm(folio))
 		type = "ksm ";
-	else if (PageAnon(page))
+	else if (folio_test_anon(folio))
 		type = "anon ";
 	else if (mapping)
 		dump_mapping(mapping);
 	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
 
-	pr_warn("%sflags: %pGp%s\n", type, &head->flags,
-		page_cma ? " CMA" : "");
-	pr_warn("page_type: %pGt\n", &head->page_type);
+	/*
+	 * Accessing the pageblock without the zone lock. It could change to
+	 * "isolate" again in the meantime, but since we are just dumping the
+	 * state for debugging, it should be fine to accept a bit of
+	 * inaccuracy here due to racing.
+	 */
+	pr_warn("%sflags: %pGp%s\n", type, &folio->flags,
+		is_migrate_cma_folio(folio, pfn) ? " CMA" : "");
+	if (page_has_type(&folio->page))
+		pr_warn("page_type: %x(%s)\n", folio->page.page_type >> 24,
+				page_type_name(folio->page.page_type));
 
 	print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
 			sizeof(unsigned long), page,
 			sizeof(struct page), false);
-	if (head != page)
+	if (folio_test_large(folio))
 		print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
-			sizeof(unsigned long), head,
-			sizeof(struct page), false);
+			sizeof(unsigned long), folio,
+			2 * sizeof(struct page), false);
+}
+
+static void __dump_page(const struct page *page)
+{
+	struct folio *foliop, folio;
+	struct page precise;
+	unsigned long head;
+	unsigned long pfn = page_to_pfn(page);
+	unsigned long idx, nr_pages = 1;
+	int loops = 5;
+
+again:
+	memcpy(&precise, page, sizeof(*page));
+	head = precise.compound_head;
+	if ((head & 1) == 0) {
+		foliop = (struct folio *)&precise;
+		idx = 0;
+		if (!folio_test_large(foliop))
+			goto dump;
+		foliop = (struct folio *)page;
+	} else {
+		foliop = (struct folio *)(head - 1);
+		idx = folio_page_idx(foliop, page);
+	}
+
+	if (idx < MAX_FOLIO_NR_PAGES) {
+		memcpy(&folio, foliop, 2 * sizeof(struct page));
+		nr_pages = folio_nr_pages(&folio);
+		foliop = &folio;
+	}
+
+	if (idx > nr_pages) {
+		if (loops-- > 0)
+			goto again;
+		pr_warn("page does not match folio\n");
+		precise.compound_head &= ~1UL;
+		foliop = (struct folio *)&precise;
+		idx = 0;
+	}
+
+dump:
+	__dump_folio(foliop, &precise, pfn, idx);
 }
 
-void dump_page(struct page *page, const char *reason)
+void dump_page(const struct page *page, const char *reason)
 {
 	if (PagePoisoned(page))
 		pr_warn("page:%p is uninitialized and poisoned", page);
@@ -162,9 +193,6 @@ EXPORT_SYMBOL(dump_vma);
 void dump_mm(const struct mm_struct *mm)
 {
 	pr_emerg("mm %px task_size %lu\n"
-#ifdef CONFIG_MMU
-		"get_unmapped_area %px\n"
-#endif
 		"mmap_base %lu mmap_legacy_base %lu\n"
 		"pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
 		"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
@@ -190,9 +218,6 @@ void dump_mm(const struct mm_struct *mm)
 		"def_flags: %#lx(%pGv)\n",
 
 		mm, mm->task_size,
-#ifdef CONFIG_MMU
-		mm->get_unmapped_area,
-#endif
 		mm->mmap_base, mm->mmap_legacy_base,
 		mm->pgd, atomic_read(&mm->mm_users),
 		atomic_read(&mm->mm_count),
@@ -224,6 +249,77 @@ void dump_mm(const struct mm_struct *mm)
 }
 EXPORT_SYMBOL(dump_mm);
 
+void dump_vmg(const struct vma_merge_struct *vmg, const char *reason)
+{
+	if (reason)
+		pr_warn("vmg %px dumped because: %s\n", vmg, reason);
+
+	if (!vmg) {
+		pr_warn("vmg %px state: (NULL)\n", vmg);
+		return;
+	}
+
+	pr_warn("vmg %px state: mm %px pgoff %lx\n"
+		"vmi %px [%lx,%lx)\n"
+		"prev %px next %px vma %px\n"
+		"start %lx end %lx flags %lx\n"
+		"file %px anon_vma %px policy %px\n"
+		"uffd_ctx %px\n"
+		"anon_name %px\n"
+		"merge_flags %x state %x\n",
+		vmg, vmg->mm, vmg->pgoff,
+		vmg->vmi, vmg->vmi ? vma_iter_addr(vmg->vmi) : 0,
+		vmg->vmi ? vma_iter_end(vmg->vmi) : 0,
+		vmg->prev, vmg->next, vmg->vma,
+		vmg->start, vmg->end, vmg->flags,
+		vmg->file, vmg->anon_vma, vmg->policy,
+#ifdef CONFIG_USERFAULTFD
+		vmg->uffd_ctx.ctx,
+#else
+		(void *)0,
+#endif
+		vmg->anon_name,
+		(int)vmg->merge_flags, (int)vmg->state);
+
+	if (vmg->mm) {
+		pr_warn("vmg %px mm:\n", vmg);
+		dump_mm(vmg->mm);
+	} else {
+		pr_warn("vmg %px mm: (NULL)\n", vmg);
+	}
+
+	if (vmg->vma) {
+		pr_warn("vmg %px vma:\n", vmg);
+		dump_vma(vmg->vma);
+	} else {
+		pr_warn("vmg %px vma: (NULL)\n", vmg);
+	}
+
+	if (vmg->prev) {
+		pr_warn("vmg %px prev:\n", vmg);
+		dump_vma(vmg->prev);
+	} else {
+		pr_warn("vmg %px prev: (NULL)\n", vmg);
+	}
+
+	if (vmg->next) {
+		pr_warn("vmg %px next:\n", vmg);
+		dump_vma(vmg->next);
+	} else {
+		pr_warn("vmg %px next: (NULL)\n", vmg);
+	}
+
+#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
+	if (vmg->vmi) {
+		pr_warn("vmg %px vmi:\n", vmg);
+		vma_iter_dump_tree(vmg->vmi);
+	} else {
+		pr_warn("vmg %px vmi: (NULL)\n", vmg);
+	}
+#endif
+}
+EXPORT_SYMBOL(dump_vmg);
+
 static bool page_init_poisoning __read_mostly = true;
 
 static int __init setup_vm_debug(char *str)