scsi: hisi_sas: Relocate some codes to avoid an unused check

In function hisi_sas_task_prep(), we check asd_sas_port, but in function
hisi_sas_task_exec(), we already refer to asd_sas_port by using function
dev_to_hisi_hba() implicitly. So to avoid this possible invalid
dereference, relocate the check to function hisi_sas_task_prep().

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 8633ff9..65dc749 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -302,36 +302,19 @@ static int hisi_sas_task_prep(struct sas_task *task,
                              int *pass)
 {
        struct domain_device *device = task->dev;
-       struct hisi_hba *hisi_hba;
+       struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
        struct hisi_sas_device *sas_dev = device->lldd_dev;
        struct hisi_sas_port *port;
        struct hisi_sas_slot *slot;
        struct hisi_sas_cmd_hdr *cmd_hdr_base;
        struct asd_sas_port *sas_port = device->port;
-       struct device *dev;
+       struct device *dev = hisi_hba->dev;
        int dlvry_queue_slot, dlvry_queue, rc, slot_idx;
        int n_elem = 0, n_elem_req = 0, n_elem_resp = 0;
        struct hisi_sas_dq *dq;
        unsigned long flags;
        int wr_q_index;
 
-       if (!sas_port) {
-               struct task_status_struct *ts = &task->task_status;
-
-               ts->resp = SAS_TASK_UNDELIVERED;
-               ts->stat = SAS_PHY_DOWN;
-               /*
-                * libsas will use dev->port, should
-                * not call task_done for sata
-                */
-               if (device->dev_type != SAS_SATA_DEV)
-                       task->task_done(task);
-               return -ECOMM;
-       }
-
-       hisi_hba = dev_to_hisi_hba(device);
-       dev = hisi_hba->dev;
-
        if (DEV_IS_GONE(sas_dev)) {
                if (sas_dev)
                        dev_info(dev, "task prep: device %d not ready\n",
@@ -506,10 +489,29 @@ static int hisi_sas_task_exec(struct sas_task *task, gfp_t gfp_flags,
        u32 rc;
        u32 pass = 0;
        unsigned long flags;
-       struct hisi_hba *hisi_hba = dev_to_hisi_hba(task->dev);
-       struct device *dev = hisi_hba->dev;
+       struct hisi_hba *hisi_hba;
+       struct device *dev;
+       struct domain_device *device = task->dev;
+       struct asd_sas_port *sas_port = device->port;
        struct hisi_sas_dq *dq = NULL;
 
+       if (!sas_port) {
+               struct task_status_struct *ts = &task->task_status;
+
+               ts->resp = SAS_TASK_UNDELIVERED;
+               ts->stat = SAS_PHY_DOWN;
+               /*
+                * libsas will use dev->port, should
+                * not call task_done for sata
+                */
+               if (device->dev_type != SAS_SATA_DEV)
+                       task->task_done(task);
+               return -ECOMM;
+       }
+
+       hisi_hba = dev_to_hisi_hba(device);
+       dev = hisi_hba->dev;
+
        if (unlikely(test_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags))) {
                if (in_softirq())
                        return -EINVAL;