linux/drivers/scsi/lpfc
Justin Tee 2cf66428a2 scsi: lpfc: Fix hard lockup when reading the rx_monitor from debugfs
[ Upstream commit c44e50f4a0 ]

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>
2022-12-31 13:14:43 +01:00
..
Makefile
lpfc.h
lpfc_attr.c
lpfc_attr.h
lpfc_bsg.c
lpfc_bsg.h
lpfc_compat.h
lpfc_crtn.h
lpfc_ct.c
lpfc_debugfs.c
lpfc_debugfs.h
lpfc_disc.h
lpfc_els.c
lpfc_hbadisc.c
lpfc_hw.h
lpfc_hw4.h
lpfc_ids.h
lpfc_init.c
lpfc_logmsg.h
lpfc_mbox.c
lpfc_mem.c
lpfc_nl.h
lpfc_nportdisc.c
lpfc_nvme.c
lpfc_nvme.h
lpfc_nvmet.c
lpfc_scsi.c
lpfc_scsi.h
lpfc_sli.c
lpfc_sli.h
lpfc_sli4.h
lpfc_version.h
lpfc_vport.c
lpfc_vport.h