[PATCH 4.19 42/88] bnx2x: fix napi API usage sequence

Greg Kroah-Hartman
2022-05-10T13:35:14Z

From: Manish Chopra <manishc@marvell.com>

[ Upstream commit af68656d66eda219b7f55ce8313a1da0312c79e1 ]

While handling PCI errors (AER flow) driver tries to
disable NAPI [napi_disable()] after NAPI is deleted
[__netif_napi_del()] which causes unexpected system
hang/crash.

System message log shows the following:
=======================================
[ 3222.537510] EEH: Detected PCI bus error on PHB#384-PE#800000 [ 3222.537511] EEH: This PCI device has failed 2 times in the last hour and will be permanently disabled after 5 failures.
[ 3222.537512] EEH: Notify device drivers to shutdown [ 3222.537513] EEH: Beginning: 'error_detected(IO frozen)'
[ 3222.537514] EEH: PE#800000 (PCI 0384:80:00.0): Invoking
bnx2x->error_detected(IO frozen)
[ 3222.537516] bnx2x: [bnx2x_io_error_detected:14236(eth14)]IO error detected [ 3222.537650] EEH: PE#800000 (PCI 0384:80:00.0): bnx2x driver reports:
'need reset'
[ 3222.537651] EEH: PE#800000 (PCI 0384:80:00.1): Invoking
bnx2x->error_detected(IO frozen)
[ 3222.537651] bnx2x: [bnx2x_io_error_detected:14236(eth13)]IO error detected [ 3222.537729] EEH: PE#800000 (PCI 0384:80:00.1): bnx2x driver reports:
'need reset'
[ 3222.537729] EEH: Finished:'error_detected(IO frozen)' with aggregate recovery state:'need reset'
[ 3222.537890] EEH: Collect temporary log [ 3222.583481] EEH: of node=0384:80:00.0 [ 3222.583519] EEH: PCI device/vendor: 168e14e4 [ 3222.583557] EEH: PCI cmd/status register: 00100140 [ 3222.583557] EEH: PCI-E capabilities and status follow:
[ 3222.583744] EEH: PCI-E 00: 00020010 012c8da2 00095d5e 00455c82 [ 3222.583892] EEH: PCI-E 10: 10820000 00000000 00000000 00000000 [ 3222.583893] EEH: PCI-E 20: 00000000 [ 3222.583893] EEH: PCI-E AER capability register set follows:
[ 3222.584079] EEH: PCI-E AER 00: 13c10001 00000000 00000000 00062030 [ 3222.584230] EEH: PCI-E AER 10: 00002000 000031c0 000001e0 00000000 [ 3222.584378] EEH: PCI-E AER 20: 00000000 00000000 00000000 00000000 [ 3222.584416] EEH: PCI-E AER 30: 00000000 00000000 [ 3222.584416] EEH: of node=0384:80:00.1 [ 3222.584454] EEH: PCI device/vendor: 168e14e4 [ 3222.584491] EEH: PCI cmd/status register: 00100140 [ 3222.584492] EEH: PCI-E capabilities and status follow:
[ 3222.584677] EEH: PCI-E 00: 00020010 012c8da2 00095d5e 00455c82 [ 3222.584825] EEH: PCI-E 10: 10820000 00000000 00000000 00000000 [ 3222.584826] EEH: PCI-E 20: 00000000 [ 3222.584826] EEH: PCI-E AER capability register set follows:
[ 3222.585011] EEH: PCI-E AER 00: 13c10001 00000000 00000000 00062030 [ 3222.585160] EEH: PCI-E AER 10: 00002000 000031c0 000001e0 00000000 [ 3222.585309] EEH: PCI-E AER 20: 00000000 00000000 00000000 00000000 [ 3222.585347] EEH: PCI-E AER 30: 00000000 00000000 [ 3222.586872] RTAS: event: 5, Type: Platform Error (224), Severity: 2 [ 3222.586873] EEH: Reset without hotplug activity [ 3224.762767] EEH: Beginning: 'slot_reset'
[ 3224.762770] EEH: PE#800000 (PCI 0384:80:00.0): Invoking
bnx2x->slot_reset()
[ 3224.762771] bnx2x: [bnx2x_io_slot_reset:14271(eth14)]IO slot reset initializing...
[ 3224.762887] bnx2x 0384:80:00.0: enabling device (0140 -> 0142) [ 3224.768157] bnx2x: [bnx2x_io_slot_reset:14287(eth14)]IO slot reset
--> driver unload

Uninterruptible tasks
=====================
crash> ps | grep UN
213 2 11 c000000004c89e00 UN 0.0 0 0 [eehd]
215 2 0 c000000004c80000 UN 0.0 0 0
[kworker/0:2]
2196 1 28 c000000004504f00 UN 0.1 15936 11136 wickedd
4287 1 9 c00000020d076800 UN 0.0 4032 3008 agetty
4289 1 20 c00000020d056680 UN 0.0 7232 3840 agetty
32423 2 26 c00000020038c580 UN 0.0 0 0
[kworker/26:3]
32871 4241 27 c0000002609ddd00 UN 0.1 18624 11648 sshd
32920 10130 16 c00000027284a100 UN 0.1 48512 12608 sendmail
33092 32987 0 c000000205218b00 UN 0.1 48512 12608 sendmail
33154 4567 16 c000000260e51780 UN 0.1 48832 12864 pickup
33209 4241 36 c000000270cb6500 UN 0.1 18624 11712 sshd
33473 33283 0 c000000205211480 UN 0.1 48512 12672 sendmail
33531 4241 37 c00000023c902780 UN 0.1 18624 11648 sshd

EEH handler hung while bnx2x sleeping and holding RTNL lock
===========================================================
crash> bt 213
PID: 213 TASK: c000000004c89e00 CPU: 11 COMMAND: "eehd"
#0 [c000000004d477e0] __schedule at c000000000c70808
#1 [c000000004d478b0] schedule at c000000000c70ee0
#2 [c000000004d478e0] schedule_timeout at c000000000c76dec
#3 [c000000004d479c0] msleep at c0000000002120cc
#4 [c000000004d479f0] napi_disable at c000000000a06448
^^^^^^^^^^^^^^^^
#5 [c000000004d47a30] bnx2x_netif_stop at c0080000018dba94 [bnx2x]
#6 [c000000004d47a60] bnx2x_io_slot_reset at c0080000018a551c [bnx2x]
#7 [c000000004d47b20] eeh_report_reset at c00000000004c9bc
#8 [c000000004d47b90] eeh_pe_report at c00000000004d1a8
#9 [c000000004d47c40] eeh_handle_normal_event at c00000000004da64

And the sleeping source code
============================
crash> dis -ls c000000000a06448
FILE: ../net/core/dev.c
LINE: 6702

6697 {
6698 might_sleep();
6699 set_bit(NAPI_STATE_DISABLE, &n->state);
6700
6701 while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
* 6702 msleep(1);
6703 while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
6704 msleep(1);
6705
6706 hrtimer_cancel(&n->timer);
6707
6708 clear_bit(NAPI_STATE_DISABLE, &n->state);
6709 }

EEH calls into bnx2x twice based on the system log above, first through
bnx2x_io_error_detected() and then bnx2x_io_slot_reset(), and executes
the following call chains:

bnx2x_io_error_detected()
+-> bnx2x_eeh_nic_unload()
+-> bnx2x_del_all_napi()
+-> __netif_napi_del()

bnx2x_io_slot_reset()
+-> bnx2x_netif_stop()
+-> bnx2x_napi_disable()
+->napi_disable()

Fix this by correcting the sequence of NAPI APIs usage,
that is delete the NAPI after disabling it.

Fixes: 7fa6f34081f1 ("bnx2x: AER revised")
Reported-by: David Christensen <drc@linux.vnet.ibm.com>
Tested-by: David Christensen <drc@linux.vnet.ibm.com>
Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Link: https://lore.kernel.org/r/20220426153913.6966-1-manishc@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index df4f77ad95c4..91ddde4d647c 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -14297,10 +14297,6 @@ static int bnx2x_eeh_nic_unload(struct bnx2x *bp)

/* Stop Tx */
bnx2x_tx_disable(bp);
- /* Delete all NAPI objects */
- bnx2x_del_all_napi(bp);
- if (CNIC_LOADED(bp))
- bnx2x_del_all_napi_cnic(bp);
netdev_reset_tc(bp->dev);

del_timer_sync(&bp->timer);
@@ -14405,6 +14401,11 @@ static pci_ers_result_t bnx2x_io_slot_reset(struct pci_dev *pdev)
bnx2x_drain_tx_queues(bp);
bnx2x_send_unload_req(bp, UNLOAD_RECOVERY);
bnx2x_netif_stop(bp, 1);
+ bnx2x_del_all_napi(bp);
+
+ if (CNIC_LOADED(bp))
+ bnx2x_del_all_napi_cnic(bp);
+
bnx2x_free_irq(bp);

/* Report UNLOAD_DONE to MCP */
--
2.35.1