s390: ctcm: fix ctcm_new_device error return code
authorArnd Bergmann <arnd@arndb.de>
Wed, 17 Apr 2019 16:29:13 +0000 (18:29 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 16 May 2019 17:43:43 +0000 (19:43 +0200)
commit6abfbc045ba1db97c6640752787abd8a78579772
tree5c470f7dd9d77f4df5a12ab4090b882fe3934fcf
parentf9b1baac265600a61d36ebaf9ba657119303b5b5
s390: ctcm: fix ctcm_new_device error return code

[ Upstream commit 27b141fc234a3670d21bd742c35d7205d03cbb3a ]

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.

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/s390/net/ctcm_main.c