From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 10 Apr 2019 18:00:07 +0200 From: Martin Schwidefsky Subject: Re: [PATCH 06/12] s390: ctcm: fix ctcm_new_device error return code In-Reply-To: <20190408212648.2407234-6-arnd@arndb.de> References: <20190408212648.2407234-1-arnd@arndb.de> <20190408212648.2407234-6-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20190410180007.4255ee21@mschwideX1> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Arnd Bergmann Cc: Heiko Carstens , Julian Wiedmann , Ursula Braun , clang-built-linux@googlegroups.com, Nick Desaulniers , Nathan Chancellor , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: On Mon, 8 Apr 2019 23:26:19 +0200 Arnd Bergmann wrote: > 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 Added to our internal tree for Julian to pick up. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.