From 7a6f93b0a873ad24631088c349e9d1ca3d4cf852 Mon Sep 17 00:00:00 2001
From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Date: Mon, 29 Apr 2013 15:08:39 -0700
Subject: [PATCH] firmware, memmap: fix firmware_map_entry leak
When hot removing memory, a firmware_map_entry which has memory range of
the memory is released by release_firmware_map_entry(). If the entry is
allocated by bootmem, release_firmware_map_entry() adds the entry to
map_entires_bootmem list when firmware_map_find_entry() finds the entry
from map_entries list. But firmware_map_find_entry never find the entry
sicne map_entires list does not have the entry. So the entry just
leaks.
Here are steps of leaking firmware_map_entry:
firmware_map_remove()
-> firmware_map_find_entry()
Find released entry from map_entries list
-> firmware_map_remove_entry()
Delete the entry from map_entries list
-> remove_sysfs_fw_map_entry()
...
-> release_firmware_map_entry()
-> firmware_map_find_entry()
Find the entry from map_entries list but the entry has been
deleted from map_entries list. So the entry is not added
to map_entries_bootmem. Thus the entry leaks
release_firmware_map_entry() should not call firmware_map_find_entry()
since releaed entry has been deleted from map_entries list. So the
patch delete firmware_map_find_entry() from releae_firmware_map_entry()
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/firmware/memmap.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 0b5b5f619c755..e2e04b007e155 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -114,12 +114,9 @@ static void __meminit release_firmware_map_entry(struct kobject *kobj)
* map_entries_bootmem here, and deleted from &map_entries in
* firmware_map_remove_entry().
*/
- if (firmware_map_find_entry(entry->start, entry->end,
- entry->type)) {
- spin_lock(&map_entries_bootmem_lock);
- list_add(&entry->list, &map_entries_bootmem);
- spin_unlock(&map_entries_bootmem_lock);
- }
+ spin_lock(&map_entries_bootmem_lock);
+ list_add(&entry->list, &map_entries_bootmem);
+ spin_unlock(&map_entries_bootmem_lock);
return;
}
--
2.39.5