From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [RFC v10][PATCH 05/13] Dump memory address space Date: Mon, 01 Dec 2008 10:00:12 -0800 Message-ID: <1228154412.2971.44.camel@nimitz> References: <1227747884-14150-1-git-send-email-orenl@cs.columbia.edu> <1227747884-14150-6-git-send-email-orenl@cs.columbia.edu> <20081128105351.GQ28946@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20081128105351.GQ28946-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Al Viro Cc: Oren Laadan , Andrew Morton , Linus Torvalds , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Thomas Gleixner , Serge Hallyn , Ingo Molnar , "H. Peter Anvin" List-Id: linux-api@vger.kernel.org On Fri, 2008-11-28 at 10:53 +0000, Al Viro wrote: > > > +static int cr_ctx_checkpoint(struct cr_ctx *ctx, pid_t pid) > > +{ > > + ctx->root_pid = pid; > > + > > + /* > > + * assume checkpointer is in container's root vfs > > + * FIXME: this works for now, but will change with real containers > > + */ > > + ctx->vfsroot = ¤t->fs->root; > > + path_get(ctx->vfsroot); > > This is going to break as soon as you get another thread doing e.g. chroot(2) > while you are in there. Yeah, we do need at least a read_lock(¤t->fs->lock) to keep people from chroot()'ing underneath us. > And it's a really, _really_ bad idea to take a > pointer to shared object, increment refcount on the current *contents* of > said object and assume that dropping refcount on the later contents of the > same will balance out. Absolutely. I assume you mean get_fs_struct(current) instead of path_get(). -- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html