Fri, Feb 22, 2019 at 11:07:56PM CET, jakub.kicin...@netronome.com wrote:
>When ethtool is calling into devlink compat code make sure we have
>a reference on the netdevice on which the operation was invoked.
>
>v3: move the hold/lock logic into devlink_compat_* functions (Florian)
>
>Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
>---
> net/core/devlink.c | 34 +++++++++++++++++++++++-----------
> net/core/ethtool.c | 13 ++-----------
> 2 files changed, 25 insertions(+), 22 deletions(-)
>
>diff --git a/net/core/devlink.c b/net/core/devlink.c
>index a13055160be0..78c6ea1870ca 100644
>--- a/net/core/devlink.c
>+++ b/net/core/devlink.c
>@@ -6430,27 +6430,39 @@ void devlink_compat_running_version(struct net_device
>*dev,
> {
> struct devlink *devlink;
>
>+ dev_hold(dev);
>+ rtnl_unlock();
Ha, I got it now. You rely on dev_hold to make sure the
devlink instance does not dissappear. But until this patch, that is not
guaranteed (or I'm missing it).
>+
> devlink = netdev_to_devlink(dev);
>- if (!devlink || !devlink->ops || !devlink->ops->info_get)
>- return;
>+ if (devlink && devlink->ops && devlink->ops->info_get) {
>+ mutex_lock(&devlink->lock);
>+ __devlink_compat_running_version(devlink, buf, len);
>+ mutex_unlock(&devlink->lock);
>+ }
>
>- mutex_lock(&devlink->lock);
>- __devlink_compat_running_version(devlink, buf, len);
>- mutex_unlock(&devlink->lock);
>+ rtnl_lock();
>+ dev_put(dev);
> }
>
> int devlink_compat_flash_update(struct net_device *dev, const char *file_name)
> {
> struct devlink *devlink;
>- int ret;
>+ int ret = -EOPNOTSUPP;
>+
>+ dev_hold(dev);
>+ rtnl_unlock();
>
> devlink = netdev_to_devlink(dev);
>- if (!devlink || !devlink->ops || !devlink->ops->flash_update)
>- return -EOPNOTSUPP;
>+ if (devlink && devlink->ops && devlink->ops->flash_update) {
>+ mutex_lock(&devlink->lock);
>+ ret = devlink->ops->flash_update(devlink, file_name,
>+ NULL, NULL);
>+ mutex_unlock(&devlink->lock);
>+ }
>+
>+ rtnl_lock();
>+ dev_put(dev);
>
>- mutex_lock(&devlink->lock);
>- ret = devlink->ops->flash_update(devlink, file_name, NULL, NULL);
>- mutex_unlock(&devlink->lock);
> return ret;
> }
>
>diff --git a/net/core/ethtool.c b/net/core/ethtool.c
>index 1320e8dce559..47558ffae423 100644
>--- a/net/core/ethtool.c
>+++ b/net/core/ethtool.c
>@@ -805,11 +805,9 @@ static noinline_for_stack int ethtool_get_drvinfo(struct
>net_device *dev,
> if (ops->get_eeprom_len)
> info.eedump_len = ops->get_eeprom_len(dev);
>
>- rtnl_unlock();
> if (!info.fw_version[0])
> devlink_compat_running_version(dev, info.fw_version,
> sizeof(info.fw_version));
>- rtnl_lock();
>
> if (copy_to_user(useraddr, &info, sizeof(info)))
> return -EFAULT;
>@@ -2040,15 +2038,8 @@ static noinline_for_stack int
>ethtool_flash_device(struct net_device *dev,
> return -EFAULT;
> efl.data[ETHTOOL_FLASH_MAX_FILENAME - 1] = 0;
>
>- if (!dev->ethtool_ops->flash_device) {
>- int ret;
>-
>- rtnl_unlock();
>- ret = devlink_compat_flash_update(dev, efl.data);
>- rtnl_lock();
>-
>- return ret;
>- }
>+ if (!dev->ethtool_ops->flash_device)
>+ return devlink_compat_flash_update(dev, efl.data);
>
> return dev->ethtool_ops->flash_device(dev, &efl);
> }
>--
>2.19.2
>
