[PATCH][next] ipmi: kcs_bmc_aspeed: Fix less than zero comparison of a unsigned int

[PATCH][next] ipmi: kcs_bmc_aspeed: Fix less than zero comparison of a unsigned int

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The comparisons of the unsigned int hw_type to less than zero always
false because it is unsigned. Fix this by using an int for the
assignment and less than zero check.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 9d2df9a0ad80 ("ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/char/ipmi/kcs_bmc_aspeed.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 0401089f8895..92a37b33494c 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -301,13 +301,15 @@ static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
 static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
 {
 	unsigned int mask, val, hw_type;
+	int ret;
 
 	if (id > 15)
 		return -EINVAL;
 
-	hw_type = aspeed_kcs_map_serirq_type(dt_type);
-	if (hw_type < 0)
-		return hw_type;
+	ret = aspeed_kcs_map_serirq_type(dt_type);
+	if (ret < 0)
+		return ret;
+	hw_type = ret;
 
 	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
 	priv->upstream_irq.id = id;
-- 
2.31.1

Re: [PATCH][next] ipmi: kcs_bmc_aspeed: Fix less than zero comparison of a unsigned int

[Corey Minyard]

On Wed, Jun 16, 2021 at 05:29:13PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The comparisons of the unsigned int hw_type to less than zero always
> false because it is unsigned. Fix this by using an int for the
> assignment and less than zero check.

Thanks, I added this to my tree.

-corey

> 
> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: 9d2df9a0ad80 ("ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/char/ipmi/kcs_bmc_aspeed.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
> index 0401089f8895..92a37b33494c 100644
> --- a/drivers/char/ipmi/kcs_bmc_aspeed.c
> +++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
> @@ -301,13 +301,15 @@ static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
>  static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
>  {
>  	unsigned int mask, val, hw_type;
> +	int ret;
>  
>  	if (id > 15)
>  		return -EINVAL;
>  
> -	hw_type = aspeed_kcs_map_serirq_type(dt_type);
> -	if (hw_type < 0)
> -		return hw_type;
> +	ret = aspeed_kcs_map_serirq_type(dt_type);
> +	if (ret < 0)
> +		return ret;
> +	hw_type = ret;
>  
>  	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
>  	priv->upstream_irq.id = id;
> -- 
> 2.31.1
> 

Re: [PATCH][next] ipmi: kcs_bmc_aspeed: Fix less than zero comparison of a unsigned int

[Andrew Jeffery]

On Thu, 17 Jun 2021, at 01:59, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The comparisons of the unsigned int hw_type to less than zero always
> false because it is unsigned. Fix this by using an int for the
> assignment and less than zero check.
> 

> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: 9d2df9a0ad80 ("ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Thanks for catching that.

Andrew