| Message ID | 20220204183630.2376998-1-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | net: device tracking improvements | expand |
On Fri, Feb 4, 2022 at 10:36 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > From: Eric Dumazet <edumazet@google.com> > > Main goal of this series is to be able to detect the following case > which apparently is still haunting us. > > dev_hold_track(dev, tracker_1, GFP_ATOMIC); > dev_hold(dev); > dev_put(dev); > dev_put(dev); // Should complain loudly here. > dev_put_track(dev, tracker_1); // instead of here (as before this series) Please do not merge. I have missed some warnings in my tests, it seems I need to refine things a bit more.
On Fri, Feb 4, 2022 at 1:51 PM Eric Dumazet <edumazet@google.com> wrote: > > On Fri, Feb 4, 2022 at 10:36 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > > From: Eric Dumazet <edumazet@google.com> > > > > Main goal of this series is to be able to detect the following case > > which apparently is still haunting us. > > > > dev_hold_track(dev, tracker_1, GFP_ATOMIC); > > dev_hold(dev); > > dev_put(dev); > > dev_put(dev); // Should complain loudly here. > > dev_put_track(dev, tracker_1); // instead of here (as before this series) > > > Please do not merge. > > I have missed some warnings in my tests, it seems I need to refine > things a bit more. I had to add the following on top of the last patch, I will send a V2 soon. diff --git a/net/core/link_watch.c b/net/core/link_watch.c index b0f5344d1185be66d05cd1dc50cffc5ccfe883ef..95098d1a49bdf4cbc3ddeb4d345e4276f974a208 100644 --- a/net/core/link_watch.c +++ b/net/core/link_watch.c @@ -166,10 +166,10 @@ static void linkwatch_do_dev(struct net_device *dev) netdev_state_change(dev); } - /* Note: our callers are responsible for - * calling netdev_tracker_free(). + /* Note: our callers are responsible for calling netdev_tracker_free(). + * This is the reason we use __dev_put() instead of dev_put(). */ - dev_put(dev); + __dev_put(dev); } static void __linkwatch_run_queue(int urgent_only)
From: Eric Dumazet <edumazet@google.com> Main goal of this series is to be able to detect the following case which apparently is still haunting us. dev_hold_track(dev, tracker_1, GFP_ATOMIC); dev_hold(dev); dev_put(dev); dev_put(dev); // Should complain loudly here. dev_put_track(dev, tracker_1); // instead of here (as before this series) Eric Dumazet (3): ref_tracker: implement use-after-free detection ref_tracker: add a count of untracked references net: refine dev_put()/dev_hold() debugging include/linux/netdevice.h | 69 ++++++++++++++++++++++++------------- include/linux/ref_tracker.h | 4 +++ lib/ref_tracker.c | 17 ++++++++- net/core/dev.c | 2 +- 4 files changed, 67 insertions(+), 25 deletions(-)