When igc_led_setup() fails, igc_probe() fails and triggers kernel panic
in free_netdev() since unregister_netdev() is not called. [1]
This behavior can be tested using fault-injection framework, especially
the failslab feature. [2]
Since LED support is not mandatory, treat LED setup failures as
non-fatal and continue probe with a warning message, consequently
avoiding the kernel panic.
[1]
kernel BUG at net/core/dev.c:12047!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 937 Comm: repro-igc-led-e Not tainted
6.17.0-rc4-enjuk-tnguy-00865-gc4940196ab02 #64 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:free_netdev+0x278/0x2b0
[...]
Call Trace:
<TASK>
igc_probe+0x370/0x910
local_pci_probe+0x3a/0x80
pci_device_probe+0xd1/0x200
[...]
[2]
#!/bin/bash -ex
FAILSLAB_PATH=/sys/kernel/debug/failslab/
DEVICE=0000:00:05.0
START_ADDR=$(grep " igc_led_setup" /proc/kallsyms \
| awk '{printf("0x%s", $1)}')
END_ADDR=$(printf "0x%x" $((START_ADDR + 0x100)))
echo $START_ADDR > $FAILSLAB_PATH/require-start
echo $END_ADDR > $FAILSLAB_PATH/require-end
echo 1 > $FAILSLAB_PATH/times
echo 100 > $FAILSLAB_PATH/probability
echo N > $FAILSLAB_PATH/ignore-gfp-wait
echo $DEVICE > /sys/bus/pci/drivers/igc/bind
Fixes: ea578703b03d ("igc: Add support for LEDs on i225/i226")
Signed-off-by: Kohei Enju <[email protected]>
---
Changes:
v1->v2:
- don't fail probe when led setup fails
- rephrase subject and commit message
v1:
https://lore.kernel.org/intel-wired-lan/[email protected]/
---
drivers/net/ethernet/intel/igc/igc.h | 1 +
drivers/net/ethernet/intel/igc/igc_main.c | 12 +++++++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc.h
b/drivers/net/ethernet/intel/igc/igc.h
index 266bfcf2a28f..a427f05814c1 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -345,6 +345,7 @@ struct igc_adapter {
/* LEDs */
struct mutex led_mutex;
struct igc_led_classdev *leds;
+ bool leds_available;
};
void igc_up(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
b/drivers/net/ethernet/intel/igc/igc_main.c
index e79b14d50b24..728d7ca5338b 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -7335,8 +7335,14 @@ static int igc_probe(struct pci_dev *pdev,
if (IS_ENABLED(CONFIG_IGC_LEDS)) {
err = igc_led_setup(adapter);
- if (err)
- goto err_register;
+ if (err) {
+ netdev_warn_once(netdev,
+ "LED init failed (%d); continuing
without LED support\n",
+ err);
+ adapter->leds_available = false;
+ } else {
+ adapter->leds_available = true;
+ }
}
return 0;
@@ -7392,7 +7398,7 @@ static void igc_remove(struct pci_dev *pdev)
cancel_work_sync(&adapter->watchdog_task);
hrtimer_cancel(&adapter->hrtimer);
- if (IS_ENABLED(CONFIG_IGC_LEDS))
+ if (IS_ENABLED(CONFIG_IGC_LEDS) && adapter->leds_available)
igc_led_free(adapter);
/* Release control of h/w to f/w. If f/w is AMT enabled, this
--
2.48.1
