linux-kernel - [linux-stable-rc:linux-4.9.y 967/2229] drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false

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Message-ID: <202207241311.Dv86CbAo-lkp@intel.com>
Date:   Sun, 24 Jul 2022 13:39:50 +0800
From:   kernel test robot <lkp@...el.com>
To:     Daniel Rosenberg <drosen@...gle.com>
Cc:     llvm@...ts.linux.dev, kbuild-all@...ts.01.org,
        linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Dennis Cagle <d-cagle@...eaurora.org>,
        Lee Jones <lee.jones@...aro.org>
Subject: [linux-stable-rc:linux-4.9.y 967/2229]
 drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is
 used uninitialized whenever 'if' condition is false

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y
head:   65be5f5665a580424a7b1102f1a04c4259c559b5
commit: a8200613c8c9fbaf7b55d4d438376ebaf0c4ce7e [967/2229] ion: Protect kref from userspace manipulation
config: mips-randconfig-r034-20220719 (https://download.01.org/0day-ci/archive/20220724/202207241311.Dv86CbAo-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project fa0c7639e91fa1cd0cf2ff0445a1634a90fe850a)
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 mips cross compiling tool for clang build
        # apt-get install binutils-mipsel-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=a8200613c8c9fbaf7b55d4d438376ebaf0c4ce7e
        git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
        git fetch --no-tags linux-stable-rc linux-4.9.y
        git checkout a8200613c8c9fbaf7b55d4d438376ebaf0c4ce7e
        # 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=mips SHELL=/bin/bash drivers/staging/android/ion/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@...el.com>

All warnings (new ones prefixed by >>):

>> drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (--handle->user_ref_count == 0)
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/staging/android/ion/ion-ioctl.c:74:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/staging/android/ion/ion-ioctl.c:71:2: note: remove the 'if' if its condition is always true
           if (--handle->user_ref_count == 0)
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/staging/android/ion/ion-ioctl.c:69:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.


vim +71 drivers/staging/android/ion/ion-ioctl.c

    65	
    66	/* Must hold the client lock */
    67	static int user_ion_handle_put_nolock(struct ion_handle *handle)
    68	{
    69		int ret;
    70	
  > 71		if (--handle->user_ref_count == 0)
    72			ret = ion_handle_put_nolock(handle);
    73	
    74		return ret;
    75	}
    76	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp