mptfusion: tweak null pointer checks

Fixes the following smatch warnings:

  drivers/message/fusion/mptbase.c:652 mptbase_reply() warn: variable
    dereferenced before check 'reply' (see line 639)

      [JL: No-brainer, the enclosing switch statement dereferences
       reply, so we can't get here unless reply is valid.]

  drivers/message/fusion/mptsas.c:1255 mptsas_taskmgmt_complete() error:
    we previously assumed 'pScsiTmReply' could be null (see line 1227)

      [HCH: Reading the code in mptsas_taskmgmt_complete it's pretty
       obvious that it can't do anything useful if mr/pScsiTmReply are
       NULL, so I suspect it would be best to just return at the
       beginning of the function.

       I'd love to understand if it actually could ever be zero, which I
       doubt.  Maybe the LSI people can shed some light on that?]

  drivers/message/fusion/mptsas.c:3888 mptsas_not_responding_devices()
    error: we previously assumed 'port_info->phy_info' could be null
    (see line 3875)

      [HCH: It's pretty obvious from reading mptsas_sas_io_unit_pg0 that
       we never register a port_info with a NULL phy_info in the lists,
       so all NULL checks on it could be deleted.]

  drivers/message/fusion/mptscsih.c:1284 mptscsih_info() error:
    we previously assumed 'h' could be null (see line 1274)

      [HCH: shost_priv can't return NULL, so the if (h) should be
       removed.]

  drivers/message/fusion/mptscsih.c:1388 mptscsih_qcmd() error: we
    previously assumed 'vdevice' could be null (see line 1373)

      [HCH: vdevice can't ever be NULL here, it's allocated in
       ->slave_alloc and thus guaranteed to be around when
       ->queuecommand is called.]

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

3 files changed, 37 insertions, 44 deletions

diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
index 9d4c7825a5f2..a896d948b79e 100644
--- a/drivers/message/fusion/mptbase.c
+++ b/drivers/message/fusion/mptbase.c
@@ -649,12 +649,10 @@ mptbase_reply(MPT_ADAPTER *ioc, MPT_FRAME_HDR *req, MPT_FRAME_HDR *reply)
         case MPI_FUNCTION_CONFIG:
         case MPI_FUNCTION_SAS_IO_UNIT_CONTROL:
                 ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_COMMAND_GOOD;
-                if (reply) {
-                        ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
-                        memcpy(ioc->mptbase_cmds.reply, reply,
-                            min(MPT_DEFAULT_FRAME_SIZE,
-                                4 * reply->u.reply.MsgLength));
-                }
+                ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
+                memcpy(ioc->mptbase_cmds.reply, reply,
+                    min(MPT_DEFAULT_FRAME_SIZE,
+                        4 * reply->u.reply.MsgLength));
                 if (ioc->mptbase_cmds.status & MPT_MGMT_STATUS_PENDING) {
                         ioc->mptbase_cmds.status &= ~MPT_MGMT_STATUS_PENDING;
                         complete(&ioc->mptbase_cmds.done);
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index b0b74c4d2645..0707fa2c701b 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -1203,27 +1203,28 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *ioc, MPT_FRAME_HDR *mf, MPT_FRAME_HDR *mr)
             "(mf = %p, mr = %p)\n", ioc->name, mf, mr));
 
         pScsiTmReply = (SCSITaskMgmtReply_t *)mr;
-        if (pScsiTmReply) {
-                dtmprintk(ioc, printk(MYIOC_s_DEBUG_FMT
-                    "\tTaskMgmt completed: fw_channel = %d, fw_id = %d,\n"
-                    "\ttask_type = 0x%02X, iocstatus = 0x%04X "
-                    "loginfo = 0x%08X,\n\tresponse_code = 0x%02X, "
-                    "term_cmnds = %d\n", ioc->name,
-                    pScsiTmReply->Bus, pScsiTmReply->TargetID,
-                    pScsiTmReply->TaskType,
-                    le16_to_cpu(pScsiTmReply->IOCStatus),
-                    le32_to_cpu(pScsiTmReply->IOCLogInfo),
-                    pScsiTmReply->ResponseCode,
-                    le32_to_cpu(pScsiTmReply->TerminationCount)));
-
-                if (pScsiTmReply->ResponseCode)
-                        mptscsih_taskmgmt_response_code(ioc,
-                        pScsiTmReply->ResponseCode);
-        }
-
-        if (pScsiTmReply && (pScsiTmReply->TaskType ==
+        if (!pScsiTmReply)
+                return 0;
+
+        dtmprintk(ioc, printk(MYIOC_s_DEBUG_FMT
+            "\tTaskMgmt completed: fw_channel = %d, fw_id = %d,\n"
+            "\ttask_type = 0x%02X, iocstatus = 0x%04X "
+            "loginfo = 0x%08X,\n\tresponse_code = 0x%02X, "
+            "term_cmnds = %d\n", ioc->name,
+            pScsiTmReply->Bus, pScsiTmReply->TargetID,
+            pScsiTmReply->TaskType,
+            le16_to_cpu(pScsiTmReply->IOCStatus),
+            le32_to_cpu(pScsiTmReply->IOCLogInfo),
+            pScsiTmReply->ResponseCode,
+            le32_to_cpu(pScsiTmReply->TerminationCount)));
+
+        if (pScsiTmReply->ResponseCode)
+                mptscsih_taskmgmt_response_code(ioc,
+                pScsiTmReply->ResponseCode);
+
+        if (pScsiTmReply->TaskType ==
             MPI_SCSITASKMGMT_TASKTYPE_QUERY_TASK || pScsiTmReply->TaskType ==
-             MPI_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET)) {
+             MPI_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET) {
                 ioc->taskmgmt_cmds.status |= MPT_MGMT_STATUS_COMMAND_GOOD;
                 ioc->taskmgmt_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
                 memcpy(ioc->taskmgmt_cmds.reply, mr,
@@ -3853,10 +3854,8 @@ retry_page:
                         phy_info = mptsas_find_phyinfo_by_sas_address(ioc,
                                         sas_info->sas_address);
 
-                        if (phy_info) {
-                                mptsas_del_end_device(ioc, phy_info);
-                                goto redo_device_scan;
-                        }
+                        mptsas_del_end_device(ioc, phy_info);
+                        goto redo_device_scan;
                 } else
                         mptsas_volume_delete(ioc, sas_info->fw.id);
         }
@@ -3867,9 +3866,8 @@ retry_page:
  redo_expander_scan:
         list_for_each_entry(port_info, &ioc->sas_topology, list) {
 
-                if (port_info->phy_info &&
-                    (!(port_info->phy_info[0].identify.device_info &
-                    MPI_SAS_DEVICE_INFO_SMP_TARGET)))
+                if (!(port_info->phy_info[0].identify.device_info &
+                    MPI_SAS_DEVICE_INFO_SMP_TARGET))
                         continue;
                 found_expander = 0;
                 handle = 0xFFFF;
diff --git a/drivers/message/fusion/mptscsih.c b/drivers/message/fusion/mptscsih.c
index 39e566803089..e7dcb2583369 100644
--- a/drivers/message/fusion/mptscsih.c
+++ b/drivers/message/fusion/mptscsih.c
@@ -1271,15 +1271,13 @@ mptscsih_info(struct Scsi_Host *SChost)
 
         h = shost_priv(SChost);
 
-        if (h) {
-                if (h->info_kbuf == NULL)
-                        if ((h->info_kbuf = kmalloc(0x1000 /* 4Kb */, GFP_KERNEL)) == NULL)
-                                return h->info_kbuf;
-                h->info_kbuf[0] = '\0';
-
-                mpt_print_ioc_summary(h->ioc, h->info_kbuf, &size, 0, 0);
-                h->info_kbuf[size-1] = '\0';
-        }
+        if (h->info_kbuf == NULL)
+                if ((h->info_kbuf = kmalloc(0x1000 /* 4Kb */, GFP_KERNEL)) == NULL)
+                        return h->info_kbuf;
+        h->info_kbuf[0] = '\0';
+
+        mpt_print_ioc_summary(h->ioc, h->info_kbuf, &size, 0, 0);
+        h->info_kbuf[size-1] = '\0';
 
         return h->info_kbuf;
 }
@@ -1368,8 +1366,7 @@ mptscsih_qcmd(struct scsi_cmnd *SCpnt)
         /* Default to untagged. Once a target structure has been allocated,
          * use the Inquiry data to determine if device supports tagged.
          */
-        if (vdevice
-            && (vdevice->vtarget->tflags & MPT_TARGET_FLAGS_Q_YES)
+        if ((vdevice->vtarget->tflags & MPT_TARGET_FLAGS_Q_YES)
             && (SCpnt->device->tagged_supported)) {
                 scsictl = scsidir | MPI_SCSIIO_CONTROL_SIMPLEQ;
                 if (SCpnt->request && SCpnt->request->ioprio) {