Martin Lau <[email protected]> writes: > On Wed, Oct 16, 2019 at 03:28:02PM +0200, Toke Høiland-Jørgensen wrote: >> It seems I forgot to add handling of devmap_hash type maps to the device >> unregister hook for devmaps. This omission causes devices to not be >> properly released, which causes hangs. >> >> Fix this by adding the missing handler. >> >> Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices >> by hashed index") >> Reported-by: Tetsuo Handa <[email protected]> >> Signed-off-by: Toke Høiland-Jørgensen <[email protected]> >> --- >> kernel/bpf/devmap.c | 34 ++++++++++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) >> >> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c >> index d27f3b60ff6d..deb9416341e9 100644 >> --- a/kernel/bpf/devmap.c >> +++ b/kernel/bpf/devmap.c >> @@ -719,6 +719,35 @@ const struct bpf_map_ops dev_map_hash_ops = { >> .map_check_btf = map_check_no_btf, >> }; >> >> +static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab, >> + struct net_device *netdev) >> +{ >> + int i; >> + >> + for (i = 0; i < dtab->n_buckets; i++) { >> + struct bpf_dtab_netdev *dev, *odev; >> + struct hlist_head *head; >> + >> + head = dev_map_index_hash(dtab, i); >> + dev = >> hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)), >> + struct bpf_dtab_netdev, >> + index_hlist); >> + >> + while (dev) { >> + odev = (netdev == dev->dev) ? dev : NULL; >> + dev = >> hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)), >> + struct bpf_dtab_netdev, >> + index_hlist); >> + >> + if (odev) { >> + hlist_del_rcu(&odev->index_hlist); > Would it race with the dev_map_hash's update/delete side?
Oh, right, seems I forgot to grab the lock; will send a v2! -Toke
