[added,to,the,4.1,stable,tree] scsi: advansys: fix uninitialized data access

Message ID 20180301152116.1486-437-alexander.levin@microsoft.com
State New
Headers show
Series
  • [added,to,the,4.1,stable,tree] scsi: advansys: fix uninitialized data access
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Commit Message

Sasha Levin March 1, 2018, 3:27 p.m.
From: Arnd Bergmann <arnd@arndb.de>


This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.

-- 
2.14.1

Patch

===============

[ Upstream commit 44a5b977128c0ffff0654392b40f4c2ce72a619b ]

gcc-7.0.1 now warns about a previously unnoticed access of uninitialized
struct members:

drivers/scsi/advansys.c: In function 'AscMsgOutSDTR':
drivers/scsi/advansys.c:3860:26: error: '*((void *)&sdtr_buf+5)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
         ((ushort)s_buffer[i + 1] << 8) | s_buffer[i]);
                          ^
drivers/scsi/advansys.c:3860:26: error: '*((void *)&sdtr_buf+7)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/scsi/advansys.c:3860:26: error: '*((void *)&sdtr_buf+5)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/scsi/advansys.c:3860:26: error: '*((void *)&sdtr_buf+7)' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The code has existed in this exact form at least since v2.6.12, and the
warning seems correct. This uses named initializers to ensure we
initialize all members of the structure.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/scsi/advansys.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 969469261353..42a14c456da0 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -6482,18 +6482,17 @@  static uchar AscGetSynPeriodIndex(ASC_DVC_VAR *asc_dvc, uchar syn_time)
 static uchar
 AscMsgOutSDTR(ASC_DVC_VAR *asc_dvc, uchar sdtr_period, uchar sdtr_offset)
 {
-	EXT_MSG sdtr_buf;
-	uchar sdtr_period_index;
-	PortAddr iop_base;
-
-	iop_base = asc_dvc->iop_base;
-	sdtr_buf.msg_type = EXTENDED_MESSAGE;
-	sdtr_buf.msg_len = MS_SDTR_LEN;
-	sdtr_buf.msg_req = EXTENDED_SDTR;
-	sdtr_buf.xfer_period = sdtr_period;
+	PortAddr iop_base = asc_dvc->iop_base;
+	uchar sdtr_period_index = AscGetSynPeriodIndex(asc_dvc, sdtr_period);
+	EXT_MSG sdtr_buf = {
+		.msg_type = EXTENDED_MESSAGE,
+		.msg_len = MS_SDTR_LEN,
+		.msg_req = EXTENDED_SDTR,
+		.xfer_period = sdtr_period,
+		.req_ack_offset = sdtr_offset,
+	};
 	sdtr_offset &= ASC_SYN_MAX_OFFSET;
-	sdtr_buf.req_ack_offset = sdtr_offset;
-	sdtr_period_index = AscGetSynPeriodIndex(asc_dvc, sdtr_period);
+
 	if (sdtr_period_index <= asc_dvc->max_sdtr_index) {
 		AscMemWordCopyPtrToLram(iop_base, ASCV_MSGOUT_BEG,
 					(uchar *)&sdtr_buf,