[luxis1999-dev-iommu:dev-iommu-5.14-rfcv1 11/20] drivers/iommu/iommufd/iommufd.c:205:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false

[kernel test robot]

tree:   https://github.com/luxis1999/dev-iommu dev-iommu-5.14-rfcv1
head:   8d2f14a235e67092365d15107cfc357e86d69629
commit: 2be7ba5547b46f6a0629995df75601f6552c40d1 [11/20] iommu/iommufd: Add IOMMU_IOASID_ALLOC/FREE
config: riscv-randconfig-r042-20211001 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 962e503cc8bc411f7523cc393acae8aae425b1c4)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/luxis1999/dev-iommu/commit/2be7ba5547b46f6a0629995df75601f6552c40d1
        git remote add luxis1999-dev-iommu https://github.com/luxis1999/dev-iommu
        git fetch --no-tags luxis1999-dev-iommu dev-iommu-5.14-rfcv1
        git checkout 2be7ba5547b46f6a0629995df75601f6552c40d1
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/iommu/iommufd/iommufd.c:205:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (refcount_read(&ioas->refs) > 1) {
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:213:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/iommu/iommufd/iommufd.c:205:2: note: remove the 'if' if its condition is always true
           if (refcount_read(&ioas->refs) > 1) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:189:17: note: initialize the variable 'ret' to silence this warning
           int ioasid, ret;
                          ^
                           = 0
   drivers/iommu/iommufd/iommufd.c:369:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:409:17: note: uninitialized use occurs here
           return ERR_PTR(ret);
                          ^~~
   drivers/iommu/iommufd/iommufd.c:369:3: note: remove the 'if' if its condition is always false
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:369:7: warning: variable 'ret' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized]
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                       ^~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:409:17: note: uninitialized use occurs here
           return ERR_PTR(ret);
                          ^~~
   drivers/iommu/iommufd/iommufd.c:369:7: note: remove the '||' if its condition is always false
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                       ^~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:359:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   3 warnings generated.


vim +205 drivers/iommu/iommufd/iommufd.c

   185	
   186	static int iommufd_ioasid_free(struct iommufd_ctx *ictx, unsigned long arg)
   187	{
   188		struct iommufd_ioas *ioas = NULL;
   189		int ioasid, ret;
   190	
   191		if (copy_from_user(&ioasid, (void __user *)arg, sizeof(ioasid)))
   192			return -EFAULT;
   193	
   194		if (ioasid < 0)
   195			return -EINVAL;
   196	
   197		mutex_lock(&ictx->lock);
   198		ioas = xa_load(&ictx->ioasid_xa, ioasid);
   199		if (IS_ERR(ioas)) {
   200			ret = -EINVAL;
   201			goto out_unlock;
   202		}
   203	
   204		/* Disallow free if refcount is not 1 */
 > 205		if (refcount_read(&ioas->refs) > 1) {
   206			ret = -EBUSY;
   207			goto out_unlock;
   208		}
   209	
   210		ioas_put_locked(ioas);
   211	out_unlock:
   212		mutex_unlock(&ictx->lock);
   213		return ret;
   214	};
   215	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
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