[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

From: kernel test robot
Date: Sun Jul 24 2022 - 01:41:56 EST


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@xxxxxxxxx/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@xxxxxxxxx>

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