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| author | Antoine Tenart <atenart@kernel.org> | 2020-12-23 22:23:23 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-12-28 13:26:46 -0800 |
| commit | 4ae2bb81649dc03dfc95875f02126b14b773f7ab (patch) | |
| tree | 5894ca9c9d9f474c897e198b9429bf2abc947bc9 | |
| parent | 2d57b4f142e0b03e854612b8e28978935414bced (diff) | |
| download | lwn-4ae2bb81649dc03dfc95875f02126b14b773f7ab.tar.gz lwn-4ae2bb81649dc03dfc95875f02126b14b773f7ab.zip | |
net-sysfs: take the rtnl lock when accessing xps_rxqs_map and num_tc
Accesses to dev->xps_rxqs_map (when using dev->num_tc) should be
protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't
see an actual bug being triggered, but let's be safe here and take the
rtnl lock while accessing the map in sysfs.
Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/core/net-sysfs.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 62ca2f2c0ee6..daf502c13d6d 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1429,22 +1429,29 @@ static struct netdev_queue_attribute xps_cpus_attribute __ro_after_init static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) { + int j, len, ret, num_tc = 1, tc = 0; struct net_device *dev = queue->dev; struct xps_dev_maps *dev_maps; unsigned long *mask, index; - int j, len, num_tc = 1, tc = 0; index = get_netdev_queue_index(queue); + if (!rtnl_trylock()) + return restart_syscall(); + if (dev->num_tc) { num_tc = dev->num_tc; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) - return -EINVAL; + if (tc < 0) { + ret = -EINVAL; + goto err_rtnl_unlock; + } } mask = bitmap_zalloc(dev->num_rx_queues, GFP_KERNEL); - if (!mask) - return -ENOMEM; + if (!mask) { + ret = -ENOMEM; + goto err_rtnl_unlock; + } rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_rxqs_map); @@ -1470,10 +1477,16 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) out_no_maps: rcu_read_unlock(); + rtnl_unlock(); + len = bitmap_print_to_pagebuf(false, buf, mask, dev->num_rx_queues); bitmap_free(mask); return len < PAGE_SIZE ? len : -EINVAL; + +err_rtnl_unlock: + rtnl_unlock(); + return ret; } static ssize_t xps_rxqs_store(struct netdev_queue *queue, const char *buf, |