1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
From c146f9bc195a9dc3ad7fd000a14540e7c9df952d Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Thu, 6 Jan 2022 01:11:15 +0200
Subject: [PATCH 4/6] net: dsa: hold rtnl_mutex when calling
dsa_master_{setup,teardown}
DSA needs to simulate master tracking events when a binding is first
with a DSA master established and torn down, in order to give drivers
the simplifying guarantee that ->master_state_change calls are made
only when the master's readiness state to pass traffic changes.
master_state_change() provide a operational bool that DSA driver can use
to understand if DSA master is operational or not.
To avoid races, we need to block the reception of
NETDEV_UP/NETDEV_CHANGE/NETDEV_GOING_DOWN events in the netdev notifier
chain while we are changing the master's dev->dsa_ptr (this changes what
netdev_uses_dsa(dev) reports).
The dsa_master_setup() and dsa_master_teardown() functions optionally
require the rtnl_mutex to be held, if the tagger needs the master to be
promiscuous, these functions call dev_set_promiscuity(). Move the
rtnl_lock() from that function and make it top-level.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/dsa/dsa2.c | 8 ++++++++
net/dsa/master.c | 4 ++--
2 files changed, 10 insertions(+), 2 deletions(-)
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -1034,6 +1034,8 @@ static int dsa_tree_setup_master(struct
struct dsa_port *dp;
int err;
+ rtnl_lock();
+
list_for_each_entry(dp, &dst->ports, list) {
if (dsa_port_is_cpu(dp)) {
err = dsa_master_setup(dp->master, dp);
@@ -1042,6 +1044,8 @@ static int dsa_tree_setup_master(struct
}
}
+ rtnl_unlock();
+
return 0;
}
@@ -1049,9 +1053,13 @@ static void dsa_tree_teardown_master(str
{
struct dsa_port *dp;
+ rtnl_lock();
+
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_cpu(dp))
dsa_master_teardown(dp->master);
+
+ rtnl_unlock();
}
static int dsa_tree_setup_lags(struct dsa_switch_tree *dst)
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -267,9 +267,9 @@ static void dsa_master_set_promiscuity(s
if (!ops->promisc_on_master)
return;
- rtnl_lock();
+ ASSERT_RTNL();
+
dev_set_promiscuity(dev, inc);
- rtnl_unlock();
}
static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
|
