From 961ed94e8a83d8881546a278bf844699af92a502 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <natechancellor@gmail.com>
Date: Mon, 3 Jun 2019 16:44:06 -0700
Subject: [PATCH] scsi: ibmvscsi: Don't use rc uninitialized in
 ibmvscsi_do_work

References: bsc#1161951 ltc#183551
Patch-mainline: v5.3-rc1
Git-commit: 961ed94e8a83d8881546a278bf844699af92a502

clang warns:

drivers/scsi/ibmvscsi/ibmvscsi.c:2126:7: warning: variable 'rc' is used
uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
        case IBMVSCSI_HOST_ACTION_NONE:
             ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/ibmvscsi/ibmvscsi.c:2151:6: note: uninitialized use occurs
here
        if (rc) {
            ^~

Initialize rc in the IBMVSCSI_HOST_ACTION_UNBLOCK case statement then
shuffle IBMVSCSI_HOST_ACTION_NONE down to the default case statement and
make it return early so that rc is never used uninitialized in this
function.

Fixes: 035a3c4046b5 ("scsi: ibmvscsi: redo driver work thread to use enum action states")
Link: https://github.com/ClangBuiltLinux/linux/issues/502
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Suggested-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/scsi/ibmvscsi/ibmvscsi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 727c31dc11a0..fcfaf037b5bf 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -2123,8 +2123,8 @@ static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
 
 	spin_lock_irqsave(hostdata->host->host_lock, flags);
 	switch (hostdata->action) {
-	case IBMVSCSI_HOST_ACTION_NONE:
 	case IBMVSCSI_HOST_ACTION_UNBLOCK:
+		rc = 0;
 		break;
 	case IBMVSCSI_HOST_ACTION_RESET:
 		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
@@ -2142,8 +2142,10 @@ static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
 		if (!rc)
 			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
 		break;
+	case IBMVSCSI_HOST_ACTION_NONE:
 	default:
-		break;
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		return;
 	}
 
 	hostdata->action = IBMVSCSI_HOST_ACTION_NONE;
-- 
2.23.0