diff options
| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2009-11-11 14:26:26 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-08 10:21:20 -0800 |
| commit | 0c98d0c6dcfb9f3f8608053b41192731630b41cd (patch) | |
| tree | cd8cb5c1d21a2fe2eb8b1e3a5f02f84796505f93 /mm | |
| parent | bd7d2351462306b3244c3572c48670c77aa21528 (diff) | |
memcg: fix wrong pointer initialization at page migration when memcg is disabled.
commit e00e431612c3a6e437a01f2129fd3843da0c982a upstream.
Lee Schermerhorn reported that he saw bad pointer dereference in
mem_cgroup_end_migration() when he disabled memcg by boot option.
memcg's page migration logic works as
mem_cgroup_prepare_migration(page, &ptr);
do page migration
mem_cgroup_end_migration(page, ptr);
Now, ptr is not initialized in prepare_migration when memcg is disabled
by boot option. This causes panic in end_migration. This patch fixes it.
Reported-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/migrate.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 939888f9ddab..598abad88f97 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -597,7 +597,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, struct page *newpage = get_new_page(page, private, &result); int rcu_locked = 0; int charge = 0; - struct mem_cgroup *mem; + struct mem_cgroup *mem = NULL; if (!newpage) return -ENOMEM; |