[3.13.y.z extended stable] Patch "memblock, memhotplug: fix wrong type in memblock_find_in_range_node()." has been added to staging queue

Kamal Mostafa kamal at canonical.com
Tue Sep 30 21:29:41 UTC 2014

This is a note to let you know that I have just added a patch titled

    memblock, memhotplug: fix wrong type in memblock_find_in_range_node().

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:


This patch is scheduled to be released in version

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see



>From 64335b5d06996aafe6a1fc78fa2ac53d9d93f9c7 Mon Sep 17 00:00:00 2001
From: Tang Chen <tangchen at cn.fujitsu.com>
Date: Fri, 29 Aug 2014 15:18:31 -0700
Subject: memblock, memhotplug: fix wrong type in

commit 0cfb8f0c3e21e36d4a6e472e4c419d58ba848698 upstream.

In memblock_find_in_range_node(), we defined ret as int.  But it should
be phys_addr_t because it is used to store the return value from

The bug has not been triggered because when allocating low memory near
the kernel end, the "int ret" won't turn out to be negative.  When we
started to allocate memory on other nodes, and the "int ret" could be
minus.  Then the kernel will panic.

A simple way to reproduce this: comment out the following code in


and the kernel won't boot.

Reported-by: Xishi Qiu <qiuxishi at huawei.com>
Signed-off-by: Tang Chen <tangchen at cn.fujitsu.com>
Tested-by: Xishi Qiu <qiuxishi at huawei.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 mm/memblock.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 53e477b..4ae6835 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -177,8 +177,7 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
 					phys_addr_t end, phys_addr_t size,
 					phys_addr_t align, int nid)
-	int ret;
-	phys_addr_t kernel_end;
+	phys_addr_t kernel_end, ret;

 	/* pump up @end */

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