From: Justin Tee justin.tee@broadcom.com
[ Upstream commit c44e50f4a0ec00c2298f31f91bc2c3e9bbd81c7e ]
During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a hard lockup similar to the call trace below may occur.
The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer interrupts as expected, so change the strength of the spin lock to _irq.
Kernel panic - not syncing: Hard LOCKUP CPU: 3 PID: 110402 Comm: cat Kdump: loaded
exception RIP: native_queued_spin_lock_slowpath+91
[IRQ stack] native_queued_spin_lock_slowpath at ffffffffb814e30b _raw_spin_lock at ffffffffb89a667a lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc] lpfc_cmf_timer at ffffffffc0abbc67 [lpfc] __hrtimer_run_queues at ffffffffb8184250 hrtimer_interrupt at ffffffffb8184ab0 smp_apic_timer_interrupt at ffffffffb8a026ba apic_timer_interrupt at ffffffffb8a01c4f [End of IRQ stack]
apic_timer_interrupt at ffffffffb8a01c4f lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc] lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc] full_proxy_read at ffffffffb83e7fc3 vfs_read at ffffffffb833fe71 ksys_read at ffffffffb83402af do_syscall_64 at ffffffffb800430b entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad
Signed-off-by: Justin Tee justin.tee@broadcom.com Link: https://lore.kernel.org/r/20221017164323.14536-2-justintee8345@gmail.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/lpfc/lpfc_sli.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 03c21167fc85..c4960da4c1c4 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -8076,10 +8076,10 @@ u32 lpfc_rx_monitor_report(struct lpfc_hba *phba, "IO_cnt", "Info", "BWutil(ms)"); }
- /* Needs to be _bh because record is called from timer interrupt + /* Needs to be _irq because record is called from timer interrupt * context */ - spin_lock_bh(ring_lock); + spin_lock_irq(ring_lock); while (*head_idx != *tail_idx) { entry = &ring[*head_idx];
@@ -8123,7 +8123,7 @@ u32 lpfc_rx_monitor_report(struct lpfc_hba *phba, if (cnt >= max_read_entries) break; } - spin_unlock_bh(ring_lock); + spin_unlock_irq(ring_lock);
return cnt; }