From c28b3bffe49e713ce67f0e36de13b8f9f0776837 Mon Sep 17 00:00:00 2001 From: Ziyang Xuan Date: Sat, 27 Aug 2022 15:20:10 +0800 Subject: [PATCH 1/2] can: raw: process optimization in raw_init() Now, register notifier after register proto successfully. It can create raw socket and set socket options once register proto successfully, so it is possible missing notifier event before register notifier successfully although this is a low probability scenario. Move notifier registration to the front of proto registration like done in j1939. In addition, register_netdevice_notifier() may fail, check its result is necessary. Signed-off-by: Ziyang Xuan Link: https://lore.kernel.org/all/7af9401f0d2d9fed36c1667b5ac9b8df8f8b87ee.1661584485.git.william.xuanziyang@huawei.com Signed-off-by: Marc Kleine-Budde --- net/can/raw.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/net/can/raw.c b/net/can/raw.c index d1bd9cc51ebea..9ae7c4206b9a3 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -942,12 +942,20 @@ static __init int raw_module_init(void) pr_info("can: raw protocol\n"); + err = register_netdevice_notifier(&canraw_notifier); + if (err) + return err; + err = can_proto_register(&raw_can_proto); - if (err < 0) + if (err < 0) { pr_err("can: registration of raw protocol failed\n"); - else - register_netdevice_notifier(&canraw_notifier); + goto register_proto_failed; + } + return 0; + +register_proto_failed: + unregister_netdevice_notifier(&canraw_notifier); return err; } From 170277c532780392051fee48260896ed280cfbef Mon Sep 17 00:00:00 2001 From: Ziyang Xuan Date: Sat, 27 Aug 2022 15:20:11 +0800 Subject: [PATCH 2/2] can: raw: use guard clause to optimize nesting in raw_rcv() We can use guard clause to optimize nesting codes like if (condition) { ... } else { return; } in raw_rcv(); Signed-off-by: Ziyang Xuan Link: https://lore.kernel.org/all/0170ad1f07dbe838965df4274fce950980fa9d1f.1661584485.git.william.xuanziyang@huawei.com Signed-off-by: Marc Kleine-Budde --- net/can/raw.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/net/can/raw.c b/net/can/raw.c index 9ae7c4206b9a3..e7dfa3584e29c 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -136,14 +136,13 @@ static void raw_rcv(struct sk_buff *oskb, void *data) /* eliminate multiple filter matches for the same skb */ if (this_cpu_ptr(ro->uniq)->skb == oskb && this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { - if (ro->join_filters) { - this_cpu_inc(ro->uniq->join_rx_count); - /* drop frame until all enabled filters matched */ - if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) - return; - } else { + if (!ro->join_filters) + return; + + this_cpu_inc(ro->uniq->join_rx_count); + /* drop frame until all enabled filters matched */ + if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) return; - } } else { this_cpu_ptr(ro->uniq)->skb = oskb; this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;