[PATCH] zsmalloc: fix obj_to_head use page_private(page) as value but not pointer

From: Hui Zhu <zhuhui@xiaomi.com>
To: <minchan@kernel.org>, <ngupta@vflare.org>, <linux-mm@kvack.org>,
	<linux-kernel@vger.kernel.org>
Cc: <teawater@gmail.com>, Hui Zhu <zhuhui@xiaomi.com>
Subject: [PATCH] zsmalloc: fix obj_to_head use page_private(page) as value but not pointer
Date: Mon, 5 Oct 2015 16:23:01 +0800	[thread overview]
Message-ID: <1444033381-5726-1-git-send-email-zhuhui@xiaomi.com> (raw)

In function obj_malloc:
	if (!class->huge)
		/* record handle in the header of allocated chunk */
		link->handle = handle;
	else
		/* record handle in first_page->private */
		set_page_private(first_page, handle);
The huge's page save handle to private directly.

But in obj_to_head:
	if (class->huge) {
		VM_BUG_ON(!is_first_page(page));
		return page_private(page);
	} else
		return *(unsigned long *)obj;
It is used as a pointer.

So change obj_to_head use page_private(page) as value but not pointer
in obj_to_head.

Signed-off-by: Hui Zhu <zhuhui@xiaomi.com>
---
 mm/zsmalloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index f135b1b..e881d4f 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -824,7 +824,7 @@ static unsigned long obj_to_head(struct size_class *class, struct page *page,
 {
 	if (class->huge) {
 		VM_BUG_ON(!is_first_page(page));
-		return *(unsigned long *)page_private(page);
+		return page_private(page);
 	} else
 		return *(unsigned long *)obj;
 }
-- 
1.9.1

