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Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet X-Patchwork-Delegate: kuba@kernel.org name_assign_type_show() runs locklessly, we should annotate accesses to dev->name_assign_type. Alternative would be to grab devnet_rename_sem semaphore from name_assign_type_show(), but this would not bring more accuracy. Signed-off-by: Eric Dumazet --- net/core/dev.c | 6 +++--- net/core/net-sysfs.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 27ba057d06c490772320775f25fc2885f0a1ff3e..d2321a68a8abb4a4253c5843952b542ed040327a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1220,13 +1220,13 @@ int dev_change_name(struct net_device *dev, const char *newname) dev->flags & IFF_UP ? " (while UP)" : ""); old_assign_type = dev->name_assign_type; - dev->name_assign_type = NET_NAME_RENAMED; + WRITE_ONCE(dev->name_assign_type, NET_NAME_RENAMED); rollback: ret = device_rename(&dev->dev, dev->name); if (ret) { memcpy(dev->name, oldname, IFNAMSIZ); - dev->name_assign_type = old_assign_type; + WRITE_ONCE(dev->name_assign_type, old_assign_type); up_write(&devnet_rename_sem); return ret; } @@ -1255,7 +1255,7 @@ int dev_change_name(struct net_device *dev, const char *newname) down_write(&devnet_rename_sem); memcpy(dev->name, oldname, IFNAMSIZ); memcpy(oldname, newname, IFNAMSIZ); - dev->name_assign_type = old_assign_type; + WRITE_ONCE(dev->name_assign_type, old_assign_type); old_assign_type = NET_NAME_RENAMED; goto rollback; } else { diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index a09d507c5b03d24a829bf7af0b7cf1e6a0bdb65a..f4c2b82674951bbeefd880ca22c54e6a32c9f988 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -125,7 +125,7 @@ static DEVICE_ATTR_RO(iflink); static ssize_t format_name_assign_type(const struct net_device *dev, char *buf) { - return sysfs_emit(buf, fmt_dec, dev->name_assign_type); + return sysfs_emit(buf, fmt_dec, READ_ONCE(dev->name_assign_type)); } static ssize_t name_assign_type_show(struct device *dev, @@ -135,7 +135,7 @@ static ssize_t name_assign_type_show(struct device *dev, struct net_device *ndev = to_net_dev(dev); ssize_t ret = -EINVAL; - if (ndev->name_assign_type != NET_NAME_UNKNOWN) + if (READ_ONCE(ndev->name_assign_type) != NET_NAME_UNKNOWN) ret = netdev_show(dev, attr, buf, format_name_assign_type); return ret;