Re: [char-misc:char-misc-linus 3/3] drivers/misc/cardreader/rtsx_usb.c:639:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

[Shuah Khan]

On 7/1/22 2:59 AM, Greg Kroah-Hartman wrote:
> On Fri, Jul 01, 2022 at 04:49:50PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-linus
> > head:   3776c78559853fd151be7c41e369fd076fb679d5
> > commit: 3776c78559853fd151be7c41e369fd076fb679d5 [3/3] misc: rtsx_usb: use separate command and response buffers
> > config: arm-buildonly-randconfig-r006-20220629 (https://download.01.org/0day-ci/archive/20220701/202207011658.rHJFVLWA-lkp@xxxxxxxxx/config)
> > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a9119143a2d1f4d0d0bc1fe0d819e5351b4e0deb)
> > reproduce (this is a W=1 build):
> >          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >          chmod +x ~/bin/make.cross
> >          # install arm cross compiling tool for clang build
> >          # apt-get install binutils-arm-linux-gnueabi
> >          # https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git/commit/?id=3776c78559853fd151be7c41e369fd076fb679d5
> >          git remote add char-misc https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> >          git fetch --no-tags char-misc char-misc-linus
> >          git checkout 3776c78559853fd151be7c41e369fd076fb679d5
> >          # save the config file
> >          mkdir build_dir && cp config build_dir/.config
> >          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/misc/cardreader/
> >
> > If you fix the issue, kindly add following tag where applicable
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >
> > All warnings (new ones prefixed by >>):
> >
> > > > drivers/misc/cardreader/rtsx_usb.c:639:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
> >             if (!ucr->rsp_buf)
> >                 ^~~~~~~~~~~~~
> >     drivers/misc/cardreader/rtsx_usb.c:678:9: note: uninitialized use occurs here
> >             return ret;
> >                    ^~~
> >     drivers/misc/cardreader/rtsx_usb.c:639:2: note: remove the 'if' if its condition is always false
> >             if (!ucr->rsp_buf)
> >             ^~~~~~~~~~~~~~~~~~
> >     drivers/misc/cardreader/rtsx_usb.c:622:9: note: initialize the variable 'ret' to silence this warning
> >             int ret;
> >                    ^
> >                     = 0
> >     1 warning generated.
>
> Odd, gcc doesn't show this for me.  Shuah, can you send a follow-on
> patch to fix this?  The warning does look correct.

gcc didn't complain when I compiled either. I will send a follow-on patch.

thanks,
-- Shuah