On 03/20, Loktionov, Aleksandr wrote:
>
>
> > -----Original Message-----
> > From: Stanislav Fomichev <[email protected]>
> > Sent: Friday, March 20, 2026 2:25 AM
> > To: [email protected]
> > Cc: [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; Nguyen, Anthony
> > L <[email protected]>; Kitszel, Przemyslaw
> > <[email protected]>; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]; Keller,
> > Jacob E <[email protected]>; [email protected];
> > [email protected]; [email protected]; Loktionov, Aleksandr
> > <[email protected]>; [email protected]; linux-
> > [email protected]; [email protected]; intel-wired-
> > [email protected]; [email protected]; linux-
> > [email protected]; [email protected];
> > [email protected]
> > Subject: [PATCH net-next v3 04/13] net: move promiscuity handling into
> > dev_rx_mode_work
> >
> > Move unicast promiscuity tracking into dev_rx_mode_work so it runs
> > under netdev_ops_lock instead of under the addr_lock spinlock. This is
> > required because __dev_set_promiscuity calls dev_change_rx_flags and
> > __dev_notify_flags, both of which may need to sleep.
> >
> > Change ASSERT_RTNL() to netdev_ops_assert_locked() in
> > __dev_set_promiscuity, netif_set_allmulti and __dev_change_flags since
> > these are now called from the work queue under the ops lock.
> >
> > Reviewed-by: Aleksandr Loktionov <[email protected]>
> > Signed-off-by: Stanislav Fomichev <[email protected]>
> > ---
> > Documentation/networking/netdevices.rst | 4 ++
> > net/core/dev.c | 79 +++++++++++++++++-------
> > -
> > 2 files changed, 57 insertions(+), 26 deletions(-)
> >
> > diff --git a/Documentation/networking/netdevices.rst
> > b/Documentation/networking/netdevices.rst
> > index dc83d78d3b27..5cdaa1a3dcc8 100644
> > --- a/Documentation/networking/netdevices.rst
> > +++ b/Documentation/networking/netdevices.rst
> > @@ -298,6 +298,10 @@ struct net_device synchronization rules
> > Notes: Sleepable version of ndo_set_rx_mode. Receives snapshots
> > of the unicast and multicast address lists.
> >
> > +ndo_change_rx_flags:
> > + Synchronization: rtnl_lock() semaphore. In addition, netdev
> > instance
> > + lock if the driver implements queue management or shaper API.
> > +
> > ndo_setup_tc:
> > ``TC_SETUP_BLOCK`` and ``TC_SETUP_FT`` are running under NFT
> > locks
> > (i.e. no ``rtnl_lock`` and no device instance lock). The rest
> > of diff --git a/net/core/dev.c b/net/core/dev.c index
> > fedc423306fc..fc5c9b14faa0 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -9574,7 +9574,7 @@ static int __dev_set_promiscuity(struct
> > net_device *dev, int inc, bool notify)
> > kuid_t uid;
> > kgid_t gid;
> >
> > - ASSERT_RTNL();
> > + netdev_ops_assert_locked(dev);
> Can you explain why do you add new hard precondition of ops lock must be held?
The context is that in f792709e0baa ("selftests: net: validate team flags
propagation") I had to add locking around NETDEV_CHANGE notifiers and
add that ugly `if (notify) netdev_ops_assert_locked` check. After this
patch I believe we are consistently calling __dev_set_promiscuity
with the ops lock (for ops locked netdev), so we can cleanup this enforcement
part.
> > promiscuity = dev->promiscuity + inc;
> > if (promiscuity == 0) {
> > @@ -9610,16 +9610,8 @@ static int __dev_set_promiscuity(struct
> > net_device *dev, int inc, bool notify)
> >
> > dev_change_rx_flags(dev, IFF_PROMISC);
> > }
>
> ...
>
> > __hw_addr_init(&uc_snap);
> > @@ -9704,16 +9720,29 @@ static void dev_rx_mode_work(struct
> > work_struct *work)
> > if (!err)
> > err = __hw_addr_list_snapshot(&mc_ref, &dev->mc,
> > dev->addr_len);
> > - netif_addr_unlock_bh(dev);
> >
> > if (err) {
> > netdev_WARN(dev, "failed to sync uc/mc
> > addresses\n");
> > __hw_addr_flush(&uc_snap);
> > __hw_addr_flush(&uc_ref);
> > __hw_addr_flush(&mc_snap);
> > + netif_addr_unlock_bh(dev);
> > goto out;
> > }
> >
> > + promisc_inc = dev_uc_promisc_update(dev);
> > +
> > + netif_addr_unlock_bh(dev);
> > + } else {
> > + netif_addr_lock_bh(dev);
> > + promisc_inc = dev_uc_promisc_update(dev);
> > + netif_addr_unlock_bh(dev);
> > + }
> > +
> > + if (promisc_inc)
> > + __dev_set_promiscuity(dev, promisc_inc, false);
> But it's being called here without any netdev_lock_ops(dev) ?
We have the following at the start of dev_rx_mode_work:
rtnl_lock();
netdev_lock_ops(dev);
Or am I looking at something else?
