!10317 improve dump_page() robustness (dd718fca) · Commits · EulixOS / Software / Kernel

fs/inode.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -589,7 +589,8 @@ void dump_mapping(const struct address_space *mapping)
		}

		dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
		if (get_kernel_nofault(dentry, dentry_ptr)) {
		if (get_kernel_nofault(dentry, dentry_ptr) \|\|
		!dentry.d_parent \|\| !dentry.d_name.name) {
		pr_warn("aops:%ps ino:%lx invalid dentry:%px\n",
		a_ops, ino, dentry_ptr);
		return;

include/linux/mm.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -2084,6 +2084,13 @@ static inline long folio_nr_pages(struct folio *folio)
		#endif
		}

		/* Only hugetlbfs can allocate folios larger than MAX_ORDER */
		#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
		#define MAX_FOLIO_NR_PAGES (1UL << PUD_ORDER)
		#else
		#define MAX_FOLIO_NR_PAGES MAX_ORDER_NR_PAGES
		#endif

		/*
		* compound_nr() returns the number of pages in this potentially compound
		* page. compound_nr() can be called on a tail page, and is defined to

include/linux/mmzone.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -75,9 +75,12 @@ extern const char * const migratetype_names[MIGRATE_TYPES];
		#ifdef CONFIG_CMA
		# define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
		# define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
		# define is_migrate_cma_folio(folio, pfn) (MIGRATE_CMA == \
		get_pfnblock_flags_mask(&folio->page, pfn, MIGRATETYPE_MASK))
		#else
		# define is_migrate_cma(migratetype) false
		# define is_migrate_cma_page(_page) false
		# define is_migrate_cma_folio(folio, pfn) false
		#endif

		static inline bool is_migrate_movable(int mt)

mm/debug.c

+72 −57

Original line number	Diff line number	Diff line
		@@ -51,84 +51,99 @@ const struct trace_print_flags vmaflag_names[] = {
		{0, NULL}
		};

		static void __dump_page(struct page *page)
		static void __dump_folio(struct folio folio, struct page page,
		unsigned long pfn, unsigned long idx)
		{
		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;
		struct address_space *mapping = folio_mapping(folio);
		int mapcount = atomic_read(&page->_mapcount) + 1;
		char *type = "";

		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);
		}

		/*
		* 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),
		/* Open-code page_mapcount() to avoid looking up a stale folio */
		if (mapcount < 0)
		mapcount = 0;
		if (folio_test_large(folio))
		mapcount += folio_entire_mapcount(folio);

		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 entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n",
		folio_order(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: %pGt\n", &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 pfn = page_to_pfn(page);
		unsigned long idx, nr_pages = 1;
		int loops = 5;

		again:
		memcpy(&precise, page, sizeof(*page));
		foliop = page_folio(&precise);
		if (foliop == (struct folio *)&precise) {
		idx = 0;
		if (!folio_test_large(foliop))
		goto dump;
		foliop = (struct folio *)page;
		} else {
		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)