lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 13 Nov 2008 07:04:27 +0530 From: Balbir Singh <balbir@...ux.vnet.ibm.com> To: Li Zefan <lizf@...fujitsu.com> CC: linux-mm@...ck.org, YAMAMOTO Takashi <yamamoto@...inux.co.jp>, Paul Menage <menage@...gle.com>, linux-kernel@...r.kernel.org, Nick Piggin <nickpiggin@...oo.com.au>, David Rientjes <rientjes@...gle.com>, Pavel Emelianov <xemul@...nvz.org>, Dhaval Giani <dhaval@...ux.vnet.ibm.com>, Andrew Morton <akpm@...ux-foundation.org>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com> Subject: Re: [RFC][mm] [PATCH 4/4] Memory cgroup hierarchy feature selector (v3) Li Zefan wrote: >> + /* >> + * If parent's use_hiearchy is set, we can't make any modifications >> + * in the child subtrees. If it is unset, then the change can >> + * occur, provided the current cgroup has no children. >> + * >> + * For the root cgroup, parent_mem is NULL, we allow value to be >> + * set if there are no children. >> + */ >> + if (!parent_mem || (!parent_mem->use_hierarchy && >> + (val == 1 || val == 0))) { >> + if (list_empty(&cont->children)) >> + mem->use_hierarchy = val; >> + else >> + retval = -EBUSY; >> + } else >> + retval = -EINVAL; >> + >> + return retval; >> +} > > As I mentioned there is a race here. :( > > echo 1 > /memcg/memory.use_hierarchy > =>if (list_empty(&cont->children)) > mkdir /memcg/0 > => mem->use_hierarchy = 0 > mem->use_hierarchy = 1; > Hi, Li, I thought I had the cgroup_lock() around that check, but I seemed to have missed it. I'll fix that in v4. -- Balbir -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists