clang points out that the return code from this function is undefined for one of the error paths: ../drivers/s390/net/ctcm_main.c:1595:7: warning: variable 'result' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (priv->channel[direction] == NULL) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/s390/net/ctcm_main.c:1638:9: note: uninitialized use occurs here return result; ^~~~~~ ../drivers/s390/net/ctcm_main.c:1595:3: note: remove the 'if' if its condition is always false if (priv->channel[direction] == NULL) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/s390/net/ctcm_main.c:1539:12: note: initialize the variable 'result' to silence this warning int result; ^ Make it return -ENODEV here, as in the related failure cases. gcc has a known bug in underreporting some of these warnings when it has already eliminated the assignment of the return code based on some earlier optimization step. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/s390/net/ctcm_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c index 7617d21cb296..f63c5c871d3d 100644 --- a/drivers/s390/net/ctcm_main.c +++ b/drivers/s390/net/ctcm_main.c @@ -1595,6 +1595,7 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev) if (priv->channel[direction] == NULL) { if (direction == CTCM_WRITE) channel_free(priv->channel[CTCM_READ]); + result = -ENODEV; goto out_dev; } priv->channel[direction]->netdev = dev; -- 2.20.0