system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-10-14 23:39:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

net: no longer acquire RTNL in threaded_show()

Browse source 
dev->threaded can be read locklessly, if we add
corresponding READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240502173926.2010646-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2024-05-02 17:39:26 +00:00 committed by Jakub Kicinski
parent 3e51f2cbbc
commit c1742dcb6b
3 changed files with 7 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/netdevice.h
View file

@ -2370,8 +2370,8 @@ struct net_device {
struct sfp_bus *sfp_bus;
struct lock_class_key *qdisc_tx_busylock;
bool proto_down;
bool threaded;
unsigned wol_enabled:1;
unsigned threaded:1;
struct list_head net_notifier_list;

4
net/core/dev.c
View file

@ -6531,7 +6531,7 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
}
}
dev->threaded = threaded;
WRITE_ONCE(dev->threaded, threaded);
/* Make sure kthread is created before THREADED bit
* is set.
@ -6622,7 +6622,7 @@ void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
* threaded mode will not be enabled in napi_enable().
*/
if (dev->threaded && napi_kthread_create(napi))
dev->threaded = 0;
dev->threaded = false;
netif_napi_set_irq(napi, -1);
}
EXPORT_SYMBOL(netif_napi_add_weight);

8
net/core/net-sysfs.c
View file

@ -605,13 +605,13 @@ static ssize_t threaded_show(struct device *dev,
struct net_device *netdev = to_net_dev(dev);
ssize_t ret = -EINVAL;
if (!rtnl_trylock())
return restart_syscall();
rcu_read_lock();
if (dev_isalive(netdev))
ret = sysfs_emit(buf, fmt_dec, netdev->threaded);
ret = sysfs_emit(buf, fmt_dec, READ_ONCE(netdev->threaded));
rcu_read_unlock();
rtnl_unlock();
return ret;
}