[PATCH] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

[PATCH] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

[Dan Carpenter]

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>
---
 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 d905d368d28c..26a88731b0cb 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -881,7 +881,7 @@ 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;
-- 
2.17.1

Re: [PATCH] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

[Logan Gunthorpe]

Thanks!

On 2019-03-25 3:17 a.m., Dan Carpenter wrote:
> 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>

Re: [PATCH] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

[Jon Mason]

On Mon, Mar 25, 2019 at 09:49:31AM -0600, Logan Gunthorpe wrote:
> Thanks!
> 
> On 2019-03-25 3:17 a.m., Dan Carpenter wrote:
> > 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>

Sorry for the delay.  The patch is now in the ntb branch.  We've
missed window for 5.2, but it will be in the 5.3 pull request.

Thanks,
Jon

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