vsprintf: Make %pGp print the hex value

All existing users of %pGp want the hex value as well as the decoded
flag names.  This looks awkward (passing the same parameter to printf
twice), so move that functionality into the core.  If we want, we
can make that optional with flag arguments to %pGp in the future.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20211019142621.2810043-6-willy@infradead.org

lib/test_printf.c

@@ -609,10 +609,14 @@ page_flags_test(int section, int node, int zone, int last_cpupid,
 		char *cmp_buf)
 {
 	unsigned long values[] = {section, node, zone, last_cpupid, kasan_tag};
-	unsigned long size = 0;
+	unsigned long size;
 	bool append = false;
 	int i;
 
+	for (i = 0; i < ARRAY_SIZE(values); i++)
+		flags |= (values[i] & pft[i].mask) << pft[i].shift;
+
+	size = scnprintf(cmp_buf, BUF_SIZE, "%#lx(", flags);
 	if (flags & PAGEFLAGS_MASK) {
 		size += scnprintf(cmp_buf + size, BUF_SIZE - size, "%s", name);
 		append = true;
@@ -625,7 +629,6 @@ page_flags_test(int section, int node, int zone, int last_cpupid,
 		if (append)
 			size += scnprintf(cmp_buf + size, BUF_SIZE - size, "|");
 
-		flags |= (values[i] & pft[i].mask) << pft[i].shift;
 		size += scnprintf(cmp_buf + size, BUF_SIZE - size, "%s=",
 				pft[i].name);
 		size += scnprintf(cmp_buf + size, BUF_SIZE - size, pft[i].fmt,
@@ -633,6 +636,8 @@ page_flags_test(int section, int node, int zone, int last_cpupid,
 		append = true;
 	}
 
+	snprintf(cmp_buf + size, BUF_SIZE - size, ")");
+
 	test(cmp_buf, "%pGp", &flags);
 }
 

lib/vsprintf.c

@@ -2023,6 +2023,11 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
 	bool append = false;
 	int i;
 
+	buf = number(buf, end, flags, default_flag_spec);
+	if (buf < end)
+		*buf = '(';
+	buf++;
+
 	/* Page flags from the main area. */
 	if (main_flags) {
 		buf = format_flags(buf, end, main_flags, pageflag_names);
@@ -2051,6 +2056,9 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
 
 		append = true;
 	}
+	if (buf < end)
+		*buf = ')';
+	buf++;
 
 	return buf;
 }

mm/debug.c

@@ -160,7 +160,7 @@ static void __dump_page(struct page *page)
 out_mapping:
 	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
 
-	pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
+	pr_warn("%sflags: %pGp%s\n", type, &head->flags,
 		page_cma ? " CMA" : "");
 	print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
 			sizeof(unsigned long), page,

mm/memory-failure.c

@@ -2109,14 +2109,14 @@ static int __soft_offline_page(struct page *page)
 			if (!list_empty(&pagelist))
 				putback_movable_pages(&pagelist);
 
-			pr_info("soft offline: %#lx: %s migration failed %d, type %lx (%pGp)\n",
-				pfn, msg_page[huge], ret, page->flags, &page->flags);
+			pr_info("soft offline: %#lx: %s migration failed %d, type %pGp\n",
+				pfn, msg_page[huge], ret, &page->flags);
 			if (ret > 0)
 				ret = -EBUSY;
 		}
 	} else {
-		pr_info("soft offline: %#lx: %s isolation failed, page count %d, type %lx (%pGp)\n",
-			pfn, msg_page[huge], page_count(page), page->flags, &page->flags);
+		pr_info("soft offline: %#lx: %s isolation failed, page count %d, type %pGp\n",
+			pfn, msg_page[huge], page_count(page), &page->flags);
 		ret = -EBUSY;
 	}
 	return ret;

mm/page_owner.c

@@ -351,12 +351,12 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
 	pageblock_mt = get_pageblock_migratetype(page);
 	page_mt  = gfp_migratetype(page_owner->gfp_mask);
 	ret += snprintf(kbuf + ret, count - ret,
-			"PFN %lu type %s Block %lu type %s Flags %#lx(%pGp)\n",
+			"PFN %lu type %s Block %lu type %s Flags %pGp\n",
 			pfn,
 			migratetype_names[page_mt],
 			pfn >> pageblock_order,
 			migratetype_names[pageblock_mt],
-			page->flags, &page->flags);
+			&page->flags);
 
 	if (ret >= count)
 		goto err;

mm/slub.c

@@ -763,9 +763,9 @@ void print_tracking(struct kmem_cache *s, void *object)
 
 static void print_page_info(struct page *page)
 {
-	pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%#lx(%pGp)\n",
+	pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%pGp\n",
 	       page, page->objects, page->inuse, page->freelist,
-	       page->flags, &page->flags);
+	       &page->flags);
 
 }