From 1af0a0948e28d83bcfa9d48cd0f992f616c5d62e Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sat, 30 Oct 2021 10:18:51 -0700 Subject: ethtool: don't drop the rtnl_lock half way thru the ioctl devlink compat code needs to drop rtnl_lock to take devlink->lock to ensure correct lock ordering. This is problematic because we're not strictly guaranteed that the netdev will not disappear after we re-lock. It may open a possibility of nested ->begin / ->complete calls. Instead of calling into devlink under rtnl_lock take a ref on the devlink instance and make the call after we've dropped rtnl_lock. We (continue to) assume that netdevs have an implicit reference on the devlink returned from ndo_get_devlink_port Note that ndo_get_devlink_port will now get called under rtnl_lock. That should be fine since none of the drivers seem to be taking serious locks inside ndo_get_devlink_port. Signed-off-by: Jakub Kicinski Reviewed-by: Leon Romanovsky Signed-off-by: David S. Miller --- net/core/devlink.c | 45 +++++++-------------------------------------- 1 file changed, 7 insertions(+), 38 deletions(-) (limited to 'net/core') diff --git a/net/core/devlink.c b/net/core/devlink.c index 100d87fd3f65..6b5ee862429e 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -11283,55 +11283,28 @@ static struct devlink_port *netdev_to_devlink_port(struct net_device *dev) return dev->netdev_ops->ndo_get_devlink_port(dev); } -static struct devlink *netdev_to_devlink(struct net_device *dev) -{ - struct devlink_port *devlink_port = netdev_to_devlink_port(dev); - - if (!devlink_port) - return NULL; - - return devlink_port->devlink; -} - -void devlink_compat_running_version(struct net_device *dev, +void devlink_compat_running_version(struct devlink *devlink, char *buf, size_t len) { - struct devlink *devlink; - - dev_hold(dev); - rtnl_unlock(); - - devlink = netdev_to_devlink(dev); - if (!devlink || !devlink->ops->info_get) - goto out; + if (!devlink->ops->info_get) + return; mutex_lock(&devlink->lock); __devlink_compat_running_version(devlink, buf, len); mutex_unlock(&devlink->lock); - -out: - rtnl_lock(); - dev_put(dev); } -int devlink_compat_flash_update(struct net_device *dev, const char *file_name) +int devlink_compat_flash_update(struct devlink *devlink, const char *file_name) { struct devlink_flash_update_params params = {}; - struct devlink *devlink; int ret; - dev_hold(dev); - rtnl_unlock(); - - devlink = netdev_to_devlink(dev); - if (!devlink || !devlink->ops->flash_update) { - ret = -EOPNOTSUPP; - goto out; - } + if (!devlink->ops->flash_update) + return -EOPNOTSUPP; ret = request_firmware(¶ms.fw, file_name, devlink->dev); if (ret) - goto out; + return ret; mutex_lock(&devlink->lock); devlink_flash_update_begin_notify(devlink); @@ -11341,10 +11314,6 @@ int devlink_compat_flash_update(struct net_device *dev, const char *file_name) release_firmware(params.fw); -out: - rtnl_lock(); - dev_put(dev); - return ret; } -- cgit v1.2.3-59-g8ed1b