cxl: Fix wrong comparison in cxl_adapter_context_get()

commit ef6cb5f1a048fdf91ccee6d63d2bfa293338502d upstream.

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

Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists")
Cc: stable@vger.kernel.org # v4.9+
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index c1ba0d42cbc865467334c25a0b62a3f1f8932a21..e0f29b8a872db807fc7e899d25ecfdc87be156d1 100644 (file)
--- 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)