[PATCH] cxl: Fix wrong comparison in cxl_adapter_context_get()

[PATCH] cxl: Fix wrong comparison in cxl_adapter_context_get()

[Vaibhav Jain]

Function atomic_inc_unless_negative() returns a bool to indicate
success/failure. However cxl_adapter_context_get() wrongly compares
the return value against '>=0' which will always be true. The patch
fixes this comparison to '==0' there by also fixing this compile time
warning:

	drivers/misc/cxl/main.c:290 cxl_adapter_context_get()
	warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned

Cc: stable@vger.kernel.org
Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
 drivers/misc/cxl/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index c1ba0d42cbc8..e0f29b8a872d 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -287,7 +287,7 @@ int cxl_adapter_context_get(struct cxl *adapter)
 	int rc;
 
 	rc = atomic_inc_unless_negative(&adapter->contexts_num);
-	return rc >= 0 ? 0 : -EBUSY;
+	return rc ? 0 : -EBUSY;
 }
 
 void cxl_adapter_context_put(struct cxl *adapter)
-- 
2.17.1

Re: [PATCH] cxl: Fix wrong comparison in cxl_adapter_context_get()

[Andrew Donnellan]

On 05/07/18 01:28, Vaibhav Jain wrote:
> Function atomic_inc_unless_negative() returns a bool to indicate
> success/failure. However cxl_adapter_context_get() wrongly compares
> the return value against '>=0' which will always be true. The patch
> fixes this comparison to '==0' there by also fixing this compile time
> warning:
> 
> 	drivers/misc/cxl/main.c:290 cxl_adapter_context_get()
> 	warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned
> 
> Cc: stable@vger.kernel.org
> Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>

Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>

-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com  IBM Australia Limited

Re: [PATCH] cxl: Fix wrong comparison in cxl_adapter_context_get()

[Frederic Barrat]

Le 04/07/2018 à 17:28, Vaibhav Jain a écrit :
> Function atomic_inc_unless_negative() returns a bool to indicate
> success/failure. However cxl_adapter_context_get() wrongly compares
> the return value against '>=0' which will always be true. The patch
> fixes this comparison to '==0' there by also fixing this compile time
> warning:
> 
> 	drivers/misc/cxl/main.c:290 cxl_adapter_context_get()
> 	warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned
> 
> Cc: stable@vger.kernel.org
> Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---

Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>


>   drivers/misc/cxl/main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
> index c1ba0d42cbc8..e0f29b8a872d 100644
> --- a/drivers/misc/cxl/main.c
> +++ b/drivers/misc/cxl/main.c
> @@ -287,7 +287,7 @@ int cxl_adapter_context_get(struct cxl *adapter)
>   	int rc;
>   
>   	rc = atomic_inc_unless_negative(&adapter->contexts_num);
> -	return rc >= 0 ? 0 : -EBUSY;
> +	return rc ? 0 : -EBUSY;
>   }
>   
>   void cxl_adapter_context_put(struct cxl *adapter)
> 

Re: cxl: Fix wrong comparison in cxl_adapter_context_get()

[Michael Ellerman]

On Wed, 2018-07-04 at 15:28:33 UTC, Vaibhav Jain wrote:
> Function atomic_inc_unless_negative() returns a bool to indicate
> success/failure. However cxl_adapter_context_get() wrongly compares
> the return value against '>=0' which will always be true. The patch
> fixes this comparison to '==0' there by also fixing this compile time
> warning:
> 
> 	drivers/misc/cxl/main.c:290 cxl_adapter_context_get()
> 	warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned
> 
> Cc: stable@vger.kernel.org
> Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/ef6cb5f1a048fdf91ccee6d63d2bfa

cheers