[PATCH 5.2 257/413] scsi: sd_zbc: Fix compilation warning

From: Greg Kroah-Hartman
Date: Wed Jul 24 2019 - 15:37:27 EST

From: Damien Le Moal <damien.lemoal@xxxxxxx>

commit 0cdc58580b37a160fac4b884266b8b7cb096f539 upstream.

kbuild test robot gets the following compilation warning using gcc 7.4
cross compilation for c6x (GCC_VERSION=7.4.0 make.cross ARCH=c6x).

In file included from include/asm-generic/bug.h:18:0,
from arch/c6x/include/asm/bug.h:12,
from include/linux/bug.h:5,
from include/linux/thread_info.h:12,
from include/asm-generic/current.h:5,
from ./arch/c6x/include/generated/asm/current.h:1,
from include/linux/sched.h:12,
from include/linux/blkdev.h:5,
from drivers//scsi/sd_zbc.c:11:
drivers//scsi/sd_zbc.c: In function 'sd_zbc_read_zones':
>> include/linux/kernel.h:62:48: warning: 'zone_blocks' may be used
uninitialized in this function [-Wmaybe-uninitialized]
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
drivers//scsi/sd_zbc.c:464:6: note: 'zone_blocks' was declared here
u32 zone_blocks;

This is a false-positive report. The variable zone_blocks is always
initialized in sd_zbc_check_zones() before use. It is not initialized
only and only if sd_zbc_check_zones() fails.

Avoid this warning by initializing the zone_blocks variable to 0.

Fixes: 5f832a395859 ("scsi: sd_zbc: Fix sd_zbc_check_zones() error checks")
Cc: Stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/scsi/sd_zbc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -417,7 +417,7 @@ int sd_zbc_read_zones(struct scsi_disk *
struct gendisk *disk = sdkp->disk;
unsigned int nr_zones;
- u32 zone_blocks;
+ u32 zone_blocks = 0;
int ret;

if (!sd_is_zoned(sdkp))