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authorEdward Cree <[email protected]>2024-06-27 16:33:51 +0100
committerJakub Kicinski <[email protected]>2024-06-28 18:53:21 -0700
commit87925151191b64d9623e63ccf11e517eacc99d7d (patch)
tree4e4c6614bd25cbc859f6f870a517085a3c63318e
parent30a32cdf6b130356805b3193a6208de25cbb2015 (diff)
net: ethtool: add a mutex protecting RSS contexts
While this is not needed to serialise the ethtool entry points (which are all under RTNL), drivers may have cause to asynchronously access dev->ethtool->rss_ctx; taking dev->ethtool->rss_lock allows them to do this safely without needing to take the RTNL. Signed-off-by: Edward Cree <[email protected]> Reviewed-by: Przemek Kitszel <[email protected]> Link: https://patch.msgid.link/7f9c15eb7525bf87af62c275dde3a8570ee8bf0a.1719502240.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <[email protected]>
-rw-r--r--include/linux/ethtool.h3
-rw-r--r--net/core/dev.c5
-rw-r--r--net/ethtool/ioctl.c7
3 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 9cdbc8e3ed5c..f74bb0cf8ed1 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -1104,10 +1104,13 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
/**
* struct ethtool_netdev_state - per-netdevice state for ethtool features
* @rss_ctx: XArray of custom RSS contexts
+ * @rss_lock: Protects entries in @rss_ctx. May be taken from
+ * within RTNL.
* @wol_enabled: Wake-on-LAN is enabled
*/
struct ethtool_netdev_state {
struct xarray rss_ctx;
+ struct mutex rss_lock;
unsigned wol_enabled:1;
};
diff --git a/net/core/dev.c b/net/core/dev.c
index 2daed4464c08..385c4091aa77 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10338,6 +10338,7 @@ int register_netdevice(struct net_device *dev)
/* rss ctx ID 0 is reserved for the default context, start from 1 */
xa_init_flags(&dev->ethtool->rss_ctx, XA_FLAGS_ALLOC1);
+ mutex_init(&dev->ethtool->rss_lock);
spin_lock_init(&dev->addr_list_lock);
netdev_set_addr_lockdep_class(dev);
@@ -11243,6 +11244,7 @@ static void netdev_rss_contexts_free(struct net_device *dev)
struct ethtool_rxfh_context *ctx;
unsigned long context;
+ mutex_lock(&dev->ethtool->rss_lock);
xa_for_each(&dev->ethtool->rss_ctx, context, ctx) {
struct ethtool_rxfh_param rxfh;
@@ -11262,6 +11264,7 @@ static void netdev_rss_contexts_free(struct net_device *dev)
kfree(ctx);
}
xa_destroy(&dev->ethtool->rss_ctx);
+ mutex_unlock(&dev->ethtool->rss_lock);
}
/**
@@ -11374,6 +11377,8 @@ void unregister_netdevice_many_notify(struct list_head *head,
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
+ mutex_destroy(&dev->ethtool->rss_lock);
+
if (skb)
rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 82c610e9e6b2..939ccd106fe1 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1285,6 +1285,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
struct netlink_ext_ack *extack = NULL;
struct ethtool_rxnfc rx_rings;
struct ethtool_rxfh rxfh;
+ bool locked = false; /* dev->ethtool->rss_lock taken */
u32 indir_bytes = 0;
bool create = false;
u8 *rss_config;
@@ -1380,6 +1381,10 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
}
}
+ if (rxfh.rss_context) {
+ mutex_lock(&dev->ethtool->rss_lock);
+ locked = true;
+ }
if (create) {
if (rxfh_dev.rss_delete) {
ret = -EINVAL;
@@ -1495,6 +1500,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
}
out:
+ if (locked)
+ mutex_unlock(&dev->ethtool->rss_lock);
kfree(rss_config);
return ret;
}