[PATCH 4.19 26/91] net: ftgmac100: Fix crash when removing driver

Greg Kroah-Hartman
2020-11-23T12:31:08Z

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit 3d5179458d22dc0b4fdc724e4bed4231a655112a ]

When removing the driver we would hit BUG_ON(!list_empty(&dev->ptype_specific))
in net/core/dev.c due to still having the NC-SI packet handler
registered.

# echo 1e660000.ethernet > /sys/bus/platform/drivers/ftgmac100/unbind
------------[ cut here ]------------
kernel BUG at net/core/dev.c:10254!
Internal error: Oops - BUG: 0 [#1] SMP ARM
CPU: 0 PID: 115 Comm: sh Not tainted 5.10.0-rc3-next-20201111-00007-g02e0365710c4 #46
Hardware name: Generic DT based system
PC is at netdev_run_todo+0x314/0x394
LR is at cpumask_next+0x20/0x24
pc : [<806f5830>] lr : [<80863cb0>] psr: 80000153
sp : 855bbd58 ip : 00000001 fp : 855bbdac
r10: 80c03d00 r9 : 80c06228 r8 : 81158c54
r7 : 00000000 r6 : 80c05dec r5 : 80c05d18 r4 : 813b9280
r3 : 813b9054 r2 : 8122c470 r1 : 00000002 r0 : 00000002
Flags: Nzcv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none
Control: 00c5387d Table: 85514008 DAC: 00000051
Process sh (pid: 115, stack limit = 0x7cb5703d)
...
Backtrace:
[<806f551c>] (netdev_run_todo) from [<80707eec>] (rtnl_unlock+0x18/0x1c)
r10:00000051 r9:854ed710 r8:81158c54 r7:80c76bb0 r6:81158c10 r5:8115b410
r4:813b9000
[<80707ed4>] (rtnl_unlock) from [<806f5db8>] (unregister_netdev+0x2c/0x30)
[<806f5d8c>] (unregister_netdev) from [<805a8180>] (ftgmac100_remove+0x20/0xa8)
r5:8115b410 r4:813b9000
[<805a8160>] (ftgmac100_remove) from [<805355e4>] (platform_drv_remove+0x34/0x4c)

Fixes: bd466c3fb5a4 ("net/faraday: Support NCSI mode")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201117024448.1170761-1-joel@jms.id.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/faraday/ftgmac100.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1884,6 +1884,8 @@ static int ftgmac100_probe(struct platfo
return 0;

err_ncsi_dev:
+ if (priv->ndev)
+ ncsi_unregister_dev(priv->ndev);
err_register_netdev:
ftgmac100_destroy_mdio(netdev);
err_setup_mdio:
@@ -1904,6 +1906,8 @@ static int ftgmac100_remove(struct platf
netdev = platform_get_drvdata(pdev);
priv = netdev_priv(netdev);

+ if (priv->ndev)
+ ncsi_unregister_dev(priv->ndev);
unregister_netdev(netdev);

clk_disable_unprepare(priv->clk);