From: Shiraz Saleem <shiraz.saleem@intel.com>
Date: Tue, 4 Feb 2020 16:38:40 -0600
Subject: i40iw: Do an RCU lookup in i40iw_add_ipv4_addr
Patch-mainline: v5.7-rc1
Git-commit: 9a4b24108d92ffaa886e37923088bd806b988948
References: git-fixes
The in_dev_for_each_ifa_rtnl() iterator in i40iw_add_ipv4_addr requires
that the rtnl lock be held. But the rtnl_trylock/unlock scheme in this
function does not guarantee it.
Replace the rtnl locking with an RCU lookup using
in_dev_for_each_ifa_rcu()
Fixes: 8e06af711bf2 ("i40iw: add main, hdr, status")
Link: https://lore.kernel.org/r/20200204223840.2151-1-shiraz.saleem@intel.com
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/hw/i40iw/i40iw_main.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
--- a/drivers/infiniband/hw/i40iw/i40iw_main.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -1212,22 +1212,19 @@ static void i40iw_add_ipv4_addr(struct i
{
struct net_device *dev;
struct in_device *idev;
- bool got_lock = true;
u32 ip_addr;
- if (!rtnl_trylock())
- got_lock = false;
-
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((((rdma_vlan_dev_vlan_id(dev) < 0xFFFF) &&
(rdma_vlan_dev_real_dev(dev) == iwdev->netdev)) ||
- (dev == iwdev->netdev)) && (dev->flags & IFF_UP)) {
+ (dev == iwdev->netdev)) && (READ_ONCE(dev->flags) & IFF_UP)) {
const struct in_ifaddr *ifa;
- idev = in_dev_get(dev);
+ idev = __in_dev_get_rcu(dev);
if (!idev)
continue;
- in_dev_for_each_ifa_rtnl(ifa, idev) {
+ in_dev_for_each_ifa_rcu(ifa, idev) {
i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM,
"IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address,
rdma_vlan_dev_vlan_id(dev), dev->dev_addr);
@@ -1239,12 +1236,9 @@ static void i40iw_add_ipv4_addr(struct i
true,
I40IW_ARP_ADD);
}
-
- in_dev_put(idev);
}
}
- if (got_lock)
- rtnl_unlock();
+ rcu_read_unlock();
}
/**