From: Simon Horman <horms@kernel.org>
To: Vladimir Oltean <vladimir.oltean@nxp.com>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Andrew Lunn <andrew@lunn.ch>,
Florian Fainelli <f.fainelli@gmail.com>,
Claudiu Manoil <claudiu.manoil@nxp.com>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
UNGLinuxDriver@microchip.com,
Colin Foster <colin.foster@in-advantage.com>
Subject: Re: [PATCH net] net: dsa: ocelot: call dsa_tag_8021q_unregister() under rtnl_lock() on driver remove
Date: Thu, 3 Aug 2023 21:29:38 +0200 [thread overview]
Message-ID: <ZMwAImhL8nH+6KLf@kernel.org> (raw)
In-Reply-To: <20230803134253.2711124-1-vladimir.oltean@nxp.com>
On Thu, Aug 03, 2023 at 04:42:53PM +0300, Vladimir Oltean wrote:
> When the tagging protocol in current use is "ocelot-8021q" and we unbind
> the driver, we see this splat:
>
> $ echo '0000:00:00.2' > /sys/bus/pci/drivers/fsl_enetc/unbind
> mscc_felix 0000:00:00.5 swp0: left promiscuous mode
> sja1105 spi2.0: Link is Down
> DSA: tree 1 torn down
> mscc_felix 0000:00:00.5 swp2: left promiscuous mode
> sja1105 spi2.2: Link is Down
> DSA: tree 3 torn down
> fsl_enetc 0000:00:00.2 eno2: left promiscuous mode
> mscc_felix 0000:00:00.5: Link is Down
> ------------[ cut here ]------------
> RTNL: assertion failed at net/dsa/tag_8021q.c (409)
> WARNING: CPU: 1 PID: 329 at net/dsa/tag_8021q.c:409 dsa_tag_8021q_unregister+0x12c/0x1a0
> Modules linked in:
> CPU: 1 PID: 329 Comm: bash Not tainted 6.5.0-rc3+ #771
> pc : dsa_tag_8021q_unregister+0x12c/0x1a0
> lr : dsa_tag_8021q_unregister+0x12c/0x1a0
> Call trace:
> dsa_tag_8021q_unregister+0x12c/0x1a0
> felix_tag_8021q_teardown+0x130/0x150
> felix_teardown+0x3c/0xd8
> dsa_tree_teardown_switches+0xbc/0xe0
> dsa_unregister_switch+0x168/0x260
> felix_pci_remove+0x30/0x60
> pci_device_remove+0x4c/0x100
> device_release_driver_internal+0x188/0x288
> device_links_unbind_consumers+0xfc/0x138
> device_release_driver_internal+0xe0/0x288
> device_driver_detach+0x24/0x38
> unbind_store+0xd8/0x108
> drv_attr_store+0x30/0x50
> ---[ end trace 0000000000000000 ]---
> ------------[ cut here ]------------
> RTNL: assertion failed at net/8021q/vlan_core.c (376)
> WARNING: CPU: 1 PID: 329 at net/8021q/vlan_core.c:376 vlan_vid_del+0x1b8/0x1f0
> CPU: 1 PID: 329 Comm: bash Tainted: G W 6.5.0-rc3+ #771
> pc : vlan_vid_del+0x1b8/0x1f0
> lr : vlan_vid_del+0x1b8/0x1f0
> dsa_tag_8021q_unregister+0x8c/0x1a0
> felix_tag_8021q_teardown+0x130/0x150
> felix_teardown+0x3c/0xd8
> dsa_tree_teardown_switches+0xbc/0xe0
> dsa_unregister_switch+0x168/0x260
> felix_pci_remove+0x30/0x60
> pci_device_remove+0x4c/0x100
> device_release_driver_internal+0x188/0x288
> device_links_unbind_consumers+0xfc/0x138
> device_release_driver_internal+0xe0/0x288
> device_driver_detach+0x24/0x38
> unbind_store+0xd8/0x108
> drv_attr_store+0x30/0x50
> DSA: tree 0 torn down
>
> This was somewhat not so easy to spot, because "ocelot-8021q" is not the
> default tagging protocol, and thus, not everyone who tests the unbinding
> path may have switched to it beforehand. The default
> felix_tag_npi_teardown() does not require rtnl_lock() to be held.
>
> Fixes: 7c83a7c539ab ("net: dsa: add a second tagger for Ocelot switches based on tag_8021q")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> drivers/net/dsa/ocelot/felix.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
> index fd7eb4a52918..9a3e5ec16972 100644
> --- a/drivers/net/dsa/ocelot/felix.c
> +++ b/drivers/net/dsa/ocelot/felix.c
> @@ -1619,8 +1619,10 @@ static void felix_teardown(struct dsa_switch *ds)
> struct felix *felix = ocelot_to_felix(ocelot);
> struct dsa_port *dp;
>
> + rtnl_lock();
> if (felix->tag_proto_ops)
> felix->tag_proto_ops->teardown(ds);
> + rtnl_unlock();
Hi Vladimir,
I am curious to know if RTNL could be taken in
felix_tag_8021q_teardown() instead.
>
> dsa_switch_for_each_available_port(dp, ds)
> ocelot_deinit_port(ocelot, dp->index);
> --
> 2.34.1
>
>
next prev parent reply other threads:[~2023-08-03 19:29 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-03 13:42 [PATCH net] net: dsa: ocelot: call dsa_tag_8021q_unregister() under rtnl_lock() on driver remove Vladimir Oltean
2023-08-03 19:29 ` Simon Horman [this message]
2023-08-04 11:10 ` Vladimir Oltean
2023-08-05 8:10 ` Simon Horman
2023-08-04 16:03 ` Colin Foster
2023-08-04 17:09 ` Vladimir Oltean
2023-08-04 21:49 ` Colin Foster
2023-08-04 22:40 ` patchwork-bot+netdevbpf
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