[PATCH 3/4] scsi: hisi_sas: Relocate call to hisi_sas_debugfs_exit()

John Garry
2019-11-12T09:34:44Z

From: Xiang Chen <chenxiang66@hisilicon.com>

Currently we call function hisi_sas_debugfs_exit() to remove debugfs_dir
before freeing interrupt irqs and destroying workqueue in the driver
remove path.

If a dump is triggered before function hisi_sas_debugfs_exit() but
debugfs_work may be called after it, so it may refer to already removed
debugfs_dir which will cause NULL pointer dereference.

To avoid it, put function hisi_sas_debugfs_exit() after free_irqs and
destroy workqueue when removing hisi_sas driver.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index b7836406debe..bf5d5f138437 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -3302,8 +3302,6 @@ static void hisi_sas_v3_remove(struct pci_dev *pdev)
struct hisi_hba *hisi_hba = sha->lldd_ha;
struct Scsi_Host *shost = sha->core.shost;

- hisi_sas_debugfs_exit(hisi_hba);
-
if (timer_pending(&hisi_hba->timer))
del_timer(&hisi_hba->timer);

@@ -3315,6 +3313,7 @@ static void hisi_sas_v3_remove(struct pci_dev *pdev)
pci_release_regions(pdev);
pci_disable_device(pdev);
hisi_sas_free(hisi_hba);
+ hisi_sas_debugfs_exit(hisi_hba);
scsi_host_put(shost);
}

--
2.17.1