diff options
| author | Alexander Duyck <alexanderduyck@fb.com> | 2026-09-14 14:09:57 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-09-18 17:19:15 -0700 |
| commit | 1b82958f3f035df5ccaab5430a2302f08a5d5351 (patch) | |
| tree | 61d8fda9622e4e92bb5fa48665387599b57d512f /drivers/net/ethernet/broadcom | |
| parent | 95c4d54ed02283e9a09e8cd7360e384daa67a741 (diff) | |
net: ethtool: keep rtnl_lock for the ioctl self test
An offline self test that brings the interface down and back up with
netif_close() / netif_open() requires rtnl_lock for both. Since the
ethtool IOCTL path became rtnl-optional for ops-locked drivers, the
ETHTOOL_TEST ioctl runs holding only the netdev instance lock, so on an
ops-locked driver the self test now tears the device down without
rtnl_lock.
With lockdep this reproduces deterministically on every offline self
test on such a driver; note the sole lock held is the instance lock, not
rtnl:
WARNING: suspicious RCU usage
net/core/netpoll.c:207 suspicious rcu_dereference_protected() usage!
1 lock held by ethtool/107:
#0: (&dev->lock){+.+.}, at: dev_ethtool
Call Trace:
netpoll_poll_disable
__dev_close_many
netif_close_many
netif_close
fbnic_self_test
dev_ethtool_locked
dev_ethtool
dev_ioctl
sock_ioctl
__x64_sys_ioctl
Without lockdep the same condition trips ASSERT_RTNL() in
__dev_close_many() / __dev_open(); that check only samples the global
rtnl state, so it can be masked by a concurrent rtnl holder, but the
device is still being reconfigured without the lock it requires.
The ethtool self_test is a legacy ioctl-only command, so an ETHTOOL_TEST
case is only needed on the ioctl path. Add an opt-in bit for drivers whose
self test needs rtnl_lock and set it on the ops-locked drivers whose
offline self test tears the interface down and up:
- fbnic (ops-locked via queue_mgmt_ops): fbnic_self_test() offline path
uses netif_close() / netif_open().
- bnxt (ops-locked via queue_mgmt_ops): bnxt_self_test() offline path
goes through bnxt_close_nic() / bnxt_half_open_nic() /
bnxt_half_close_nic() / bnxt_open_nic(), which close and reopen the
device.
Fixes: f994752b1127 ("net: ethtool: optionally skip rtnl_lock on IOCTL path")
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/178942019771.7700.338431553546884773.stgit@ahduyck-xeon-server.home.arpa
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/broadcom')
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c index 62bc9cae613c..622e89587e5d 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -5733,7 +5733,8 @@ const struct ethtool_ops bnxt_ethtool_ops = { .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | ETHTOOL_OP_NEEDS_RTNL_SCOALESCE | - ETHTOOL_OP_NEEDS_RTNL_RSS, + ETHTOOL_OP_NEEDS_RTNL_RSS | + ETHTOOL_OP_NEEDS_RTNL_TEST, .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USECS_IRQ | |