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From:   "zhaoyang.huang" <zhaoyang.huang@unisoc.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Matthew Wilcox <willy@infradead.org>,
        Zhaoyang Huang <huangzhaoyang@gmail.com>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <ke.wang@unisoc.com>,
        <steve.kang@unisoc.com>
Subject: [RFC PATCH] mm: track bad page via kmemleak
Date:   Tue, 20 Sep 2022 21:11:08 +0800
Message-ID: <1663679468-16757-1-git-send-email-zhaoyang.huang@unisoc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

Bad pages will failed go back to allocator and leaved as orphan pages, track
them down via kmemleak.

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
 mm/page_alloc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e5486d4..24f682e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1408,7 +1408,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 			__memcg_kmem_uncharge_page(page, order);
 		reset_page_owner(page, order);
 		page_table_check_free(page, order);
-		return false;
+		goto err;
 	}
 
 	/*
@@ -1442,7 +1442,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	if (check_free)
 		bad += check_free_page(page);
 	if (bad)
-		return false;
+		goto err;
 
 	page_cpupid_reset_last(page);
 	page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
@@ -1486,6 +1486,10 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	debug_pagealloc_unmap_pages(page, 1 << order);
 
 	return true;
+err:
+	kmemleak_alloc(page_address(page), PAGE_SIZE << order, 1, GFP_KERNEL);
+	return false;
+
 }
 
 #ifdef CONFIG_DEBUG_VM
-- 
1.9.1