On Thu, 5 Sep 2013, Michal Hocko wrote: > From 4cee36f56100f5689fe1ae22f468016ce5a0cbae Mon Sep 17 00:00:00 2001 > From: Michal Hocko <mhocko@xxxxxxx> > Date: Thu, 5 Sep 2013 15:39:20 +0200 > Subject: [PATCH] memcg, oom: lock mem_cgroup_print_oom_info > > mem_cgroup_print_oom_info uses a static buffer (memcg_name) to store the > name of the cgroup. This is not safe as pointed out by David Rientjes > because although memcg oom is locked for its hierarchy nothing prevents > another parallel hierarchy to trigger oom as well and overwrite the > already in-use buffer. > > This patch introduces oom_info_lock hidden inside mem_cgroup_print_oom_info > which is held throughout the function. It make access to memcg_name safe > and as a bonus it also prevents parallel memcg ooms to interleave their > statistics which would make the printed data hard to analyze otherwise. > > Using the spinlock is OK here because this path is not hot and > meaningful data is much more important. > > Reported-by: David Rientjes <rientjes@xxxxxxxxxx> Remove this. > Signed-off-by: Michal Hocko <mhocko@xxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>