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authorEric Dumazet <edumazet@google.com>2024-05-02 19:39:26 +0200
committerJakub Kicinski <kuba@kernel.org>2024-05-04 00:14:01 +0200
commitc1742dcb6bda5fd535fbaa2145f0a180bc329aa6 (patch)
tree2552435caf76a6cf8dd78f0d734c953b517ace36 /net/core
parenttools: ynl: add --list-ops and --list-msgs to CLI (diff)
downloadlinux-c1742dcb6bda5fd535fbaa2145f0a180bc329aa6.tar.xz
linux-c1742dcb6bda5fd535fbaa2145f0a180bc329aa6.zip
net: no longer acquire RTNL in threaded_show()
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>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c4
-rw-r--r--net/core/net-sysfs.c8
2 files changed, 6 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index e02d2363347e..d6b24749eb2e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -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);
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 1f7f09e56771..4c27a360c294 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -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;
}