[PATCH AUTOSEL 4.19 409/671] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

Sasha Levin
2020-01-16T18:52:00Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit ff148d8ac53e59802645bd3200c811620317eb9f ]

This code triggers a Smatch warning:

drivers/ntb/hw/mscc/ntb_hw_switchtec.c:884 switchtec_ntb_init_sndev()
warn: should '(1 << sndev->peer_partition)' be a 64 bit type?

The "part_map" and "tpart_vec" variables are u64 type so this seems like
a valid warning.

Fixes: 3df54c870f52 ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index 9916bc5b6759..313f6258c424 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -899,7 +899,7 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
}

sndev->peer_partition = ffs(tpart_vec) - 1;
- if (!(part_map & (1 << sndev->peer_partition))) {
+ if (!(part_map & (1ULL << sndev->peer_partition))) {
dev_err(&sndev->stdev->dev,
"ntb target partition is not NT partition\n");
return -ENODEV;
--
2.20.1