diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-12-05 00:02:34 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-07 04:41:28 +0300 |
| commit | 6c36b5c244d6cb22ef8ea2f6b5da46f5171b37a5 (patch) | |
| tree | 1c7080d24f60e962449a686aca092b0e1b22467f | |
| parent | e36d46b9af682bac7c376638cf0fd98d18b98653 (diff) | |
| download | linux-6c36b5c244d6cb22ef8ea2f6b5da46f5171b37a5.tar.xz | |
net: tipc: remove one synchronize_net() from tipc_nametbl_stop()
tipc_exit_net() is very slow and is abused by syzbot.
tipc_nametbl_stop() is called for each netns being dismantled.
Calling synchronize_net() right before freeing tn->nametbl
is a big hammer.
Replace this with kfree_rcu().
Note that RCU is not properly used here, otherwise
tn->nametbl should be cleared before the synchronize_net()
or kfree_rcu(), or even before the cleanup loop.
We might need to fix this at some point.
Also note tipc uses other synchronize_rcu() calls,
more work is needed to make tipc_exit_net() much faster.
List of remaining calls to synchronize_rcu()
tipc_detach_loopback() (dev_remove_pack())
tipc_bcast_stop()
tipc_sk_rht_destroy()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241204210234.319484-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/tipc/name_table.c | 4 | ||||
| -rw-r--r-- | net/tipc/name_table.h | 2 |
2 files changed, 4 insertions, 2 deletions
diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index d1180370fdf4..e74940eab3a4 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -949,8 +949,8 @@ void tipc_nametbl_stop(struct net *net) } spin_unlock_bh(&tn->nametbl_lock); - synchronize_net(); - kfree(nt); + /* TODO: clear tn->nametbl, implement proper RCU rules ? */ + kfree_rcu(nt, rcu); } static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg, diff --git a/net/tipc/name_table.h b/net/tipc/name_table.h index 3bcd9ef8cee3..7ff6eeebaae6 100644 --- a/net/tipc/name_table.h +++ b/net/tipc/name_table.h @@ -90,6 +90,7 @@ struct publication { /** * struct name_table - table containing all existing port name publications + * @rcu: RCU callback head used for deferred freeing * @services: name sequence hash lists * @node_scope: all local publications with node scope * - used by name_distr during re-init of name table @@ -102,6 +103,7 @@ struct publication { * @snd_nxt: next sequence number to be used */ struct name_table { + struct rcu_head rcu; struct hlist_head services[TIPC_NAMETBL_SIZE]; struct list_head node_scope; struct list_head cluster_scope; |