On 2/19/07, Balbir Singh <[EMAIL PROTECTED]> wrote: > > > > More worrisome is the potential for use-after-free. What prevents the > > pointer at mm->container from referring to freed memory after we're dropped > > the lock? > > > > The container cannot be freed unless all tasks holding references to it are > gone,
... or have been moved to other containers. If you're not holding task->alloc_lock or one of the container mutexes, there's nothing to stop the task being moved to another container, and the container being deleted. If you're in an RCU section then you can guarantee that the container (that you originally read from the task) and its subsystems at least won't be deleted while you're accessing them, but for accounting like this I suspect that's not enough, since you need to be adding to the accounting stats on the correct container. I think you'll need to hold mm->container_lock for the duration of memctl_update_rss() Paul ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ ckrm-tech mailing list https://lists.sourceforge.net/lists/listinfo/ckrm-tech
