[PATCH AUTOSEL 5.6 50/73] scsi: lpfc: Fix lockdep error - register non-static key

From: Sasha Levin
Date: Sat Apr 18 2020 - 09:51:10 EST


From: James Smart <jsmart2021@xxxxxxxxx>

[ Upstream commit f861f596714bed06069f1109b89e51f3855c4ddf ]

The following lockdep error was reported when unloading the lpfc driver:

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
...
Call Trace:
dump_stack+0x96/0xe0
register_lock_class+0x8b8/0x8c0
? lockdep_hardirqs_on+0x190/0x280
? is_dynamic_key+0x150/0x150
? wait_for_completion_interruptible+0x2a0/0x2a0
? wake_up_q+0xd0/0xd0
__lock_acquire+0xda/0x21a0
? register_lock_class+0x8c0/0x8c0
? synchronize_rcu_expedited+0x500/0x500
? __call_rcu+0x850/0x850
lock_acquire+0xf3/0x1f0
? del_timer_sync+0x5/0xb0
del_timer_sync+0x3c/0xb0
? del_timer_sync+0x5/0xb0
lpfc_pci_remove_one.cold.102+0x8b7/0x935 [lpfc]
...

Unloading the driver resulted in a call to del_timer_sync for the
cpuhp_poll_timer. However the call to setup the timer had never been made,
so the timer structures used by lockdep checking were not initialized.

Unconditionally call setup_timer for the cpuhp_poll_timer during driver
initialization. Calls to start the timer remain "as needed".

Link: https://lore.kernel.org/r/20200322181304.37655-3-jsmart2021@xxxxxxxxx
Signed-off-by: James Smart <jsmart2021@xxxxxxxxx>
Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_init.c | 5 ++---
drivers/scsi/lpfc/lpfc_sli.c | 6 ++----
2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index d2bbcf8cae4c3..48fde2b1ebbab 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -11203,11 +11203,9 @@ static void lpfc_cpuhp_add(struct lpfc_hba *phba)

rcu_read_lock();

- if (!list_empty(&phba->poll_list)) {
- timer_setup(&phba->cpuhp_poll_timer, lpfc_sli4_poll_hbtimer, 0);
+ if (!list_empty(&phba->poll_list))
mod_timer(&phba->cpuhp_poll_timer,
jiffies + msecs_to_jiffies(LPFC_POLL_HB));
- }

rcu_read_unlock();

@@ -13173,6 +13171,7 @@ lpfc_pci_probe_one_s4(struct pci_dev *pdev, const struct pci_device_id *pid)
lpfc_sli4_ras_setup(phba);

INIT_LIST_HEAD(&phba->poll_list);
+ timer_setup(&phba->cpuhp_poll_timer, lpfc_sli4_poll_hbtimer, 0);
cpuhp_state_add_instance_nocalls(lpfc_cpuhp_state, &phba->cpuhp);

return 0;
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index de97727458fc7..396e24764a1b1 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -14457,12 +14457,10 @@ static inline void lpfc_sli4_add_to_poll_list(struct lpfc_queue *eq)
{
struct lpfc_hba *phba = eq->phba;

- if (list_empty(&phba->poll_list)) {
- timer_setup(&phba->cpuhp_poll_timer, lpfc_sli4_poll_hbtimer, 0);
- /* kickstart slowpath processing for this eq */
+ /* kickstart slowpath processing if needed */
+ if (list_empty(&phba->poll_list))
mod_timer(&phba->cpuhp_poll_timer,
jiffies + msecs_to_jiffies(LPFC_POLL_HB));
- }

list_add_rcu(&eq->_poll_list, &phba->poll_list);
synchronize_rcu();
--
2.20.1