linux-kernel - [PATCH] mm/page_alloc: Consolidate unlikely handling in page_expected

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250321011304.549908-1-ye.liu@linux.dev>
Date: Fri, 21 Mar 2025 09:13:04 +0800
From: Ye Liu <ye.liu@...ux.dev>
To: akpm@...ux-foundation.org
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Ye Liu <liuye@...inos.cn>
Subject: [PATCH] mm/page_alloc: Consolidate unlikely handling in page_expected_state

From: Ye Liu <liuye@...inos.cn>

This patch consolidates the handling of unlikely conditions in the
page_expected_state function, reducing code duplication and improving
readability.

Previously, the check_new_page_bad function contained logic to handle
__PG_HWPOISON flags, which was called from check_new_page. This patch
moves the handling of __PG_HWPOISON flags into the page_expected_state
function and removes the check_new_page_bad function. The check_new_page
function now directly calls bad_page if the page has unexpected flags.

This change simplifies the code by reducing the number of functions and
centralizing the unlikely condition handling in one place.

Signed-off-by: Ye Liu <liuye@...inos.cn>
---
 mm/page_alloc.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2842da893eea..d8d04ac1d709 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -892,6 +892,13 @@ static inline bool page_expected_state(struct page *page,
 	if (unlikely(atomic_read(&page->_mapcount) != -1))
 		return false;
 
+	if (unlikely(PageHWPoison(page))) {
+		/* Don't complain about hwpoisoned pages */
+		if (PageBuddy(page))
+			__ClearPageBuddy(page);
+		return false;
+	}
+
 	if (unlikely((unsigned long)page->mapping |
 			page_ref_count(page) |
 #ifdef CONFIG_MEMCG
@@ -1586,29 +1593,16 @@ static __always_inline void page_del_and_expand(struct zone *zone,
 	account_freepages(zone, -nr_pages, migratetype);
 }
 
-static void check_new_page_bad(struct page *page)
-{
-	if (unlikely(PageHWPoison(page))) {
-		/* Don't complain about hwpoisoned pages */
-		if (PageBuddy(page))
-			__ClearPageBuddy(page);
-		return;
-	}
-
-	bad_page(page,
-		 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
-}
-
 /*
  * This page is about to be returned from the page allocator
  */
 static bool check_new_page(struct page *page)
 {
-	if (likely(page_expected_state(page,
-				PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
+	if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_PREP)))
 		return false;
 
-	check_new_page_bad(page);
+	bad_page(page,
+		 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
 	return true;
 }
 
-- 
2.25.1