From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH 4/6] cr: checkpoint and restore task credentials Date: Wed, 20 May 2009 16:40:27 -0500 Message-ID: <20090520214027.GA3517@us.ibm.com> References: <20090519014446.GA28277@us.ibm.com> <20090519014538.GD28312@us.ibm.com> <4A1435E0.3010306@cs.columbia.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <4A1435E0.3010306-eQaUEPhvms7ENvBUuze7eA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Oren Laadan Cc: Linux Containers , David Howells List-Id: containers.vger.kernel.org Quoting Oren Laadan (orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org): > > /* dump the task_struct of a given task */ > > static int checkpoint_task_struct(struct ckpt_ctx *ctx, struct task_struct *t) > > { > > struct ckpt_hdr_task *h; > > int ret; > > + int realcred_ref, ecred_ref; > > + > > + realcred_ref = checkpoint_obj(ctx, t->real_cred, CKPT_OBJ_CRED); > > + if (realcred_ref < 0) > > + return realcred_ref; > > + > > + ecred_ref = checkpoint_obj(ctx, t->cred, CKPT_OBJ_CRED); > > + if (ecred_ref < 0) > > + return ecred_ref; > > Is this safe even if the checkpointed task's state changes ? > (e.g. unfrozen - yes, I know there is a patch in the works to > prevent this; but if we ever want to checkpoint STOPPED tasks... > for instance). > > Would incrementing the refcount on t->{cred,real_cred} help ? Doesn't checkpoint_obj already do that through obj_new? -serge