Date:   Fri, 1 Oct 2021 12:30:32 +0800
From:   kernel test robot <lkp@...el.com>
To:     Liu Yi L <yi.l.liu@...el.com>
Cc:     llvm@...ts.linux.dev, kbuild-all@...ts.01.org,
        linux-kernel@...r.kernel.org
Subject: [luxis1999-dev-iommu:dev-iommu-5.14-rfcv1 7/20]
 drivers/iommu/iommufd/iommufd.c:181:7: warning: variable 'ret' is used
 uninitialized whenever 'if' condition is true

tree:   https://github.com/luxis1999/dev-iommu dev-iommu-5.14-rfcv1
head:   8d2f14a235e67092365d15107cfc357e86d69629
commit: e2fbb8c54de073a2a173e15b62884c64e6c4a4b6 [7/20] iommu/iommufd: Add iommufd_[un]bind_device()
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/e2fbb8c54de073a2a173e15b62884c64e6c4a4b6
        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 e2fbb8c54de073a2a173e15b62884c64e6c4a4b6
        # 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@...el.com>

All warnings (new ones prefixed by >>):

>> drivers/iommu/iommufd/iommufd.c:181:7: 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:221:17: note: uninitialized use occurs here
           return ERR_PTR(ret);
                          ^~~
   drivers/iommu/iommufd/iommufd.c:181:3: note: remove the 'if' if its condition is always false
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/iommu/iommufd/iommufd.c:181:7: 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:221:17: note: uninitialized use occurs here
           return ERR_PTR(ret);
                          ^~~
   drivers/iommu/iommufd/iommufd.c:181:7: note: remove the '||' if its condition is always false
                   if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
                       ^~~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/iommufd.c:171:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   2 warnings generated.


vim +181 drivers/iommu/iommufd/iommufd.c

   151	
   152	/**
   153	 * iommufd_bind_device - Bind a physical device marked by a device
   154	 *			 cookie to an iommu fd.
   155	 * @fd:		[in] iommufd file descriptor.
   156	 * @dev:	[in] Pointer to a physical device struct.
   157	 * @dev_cookie:	[in] A cookie to mark the device in /dev/iommu uAPI.
   158	 *
   159	 * A successful bind establishes a security context for the device
   160	 * and returns struct iommufd_device pointer. Otherwise returns
   161	 * error pointer.
   162	 *
   163	 */
   164	struct iommufd_device *iommufd_bind_device(int fd, struct device *dev,
   165						   u64 dev_cookie)
   166	{
   167		struct iommufd_ctx *ictx;
   168		struct iommufd_device *idev;
   169		unsigned long index;
   170		unsigned int id;
   171		int ret;
   172	
   173		ictx = iommufd_ctx_fdget(fd);
   174		if (!ictx)
   175			return ERR_PTR(-EINVAL);
   176	
   177		mutex_lock(&ictx->lock);
   178	
   179		/* check duplicate registration */
   180		xa_for_each(&ictx->device_xa, index, idev) {
 > 181			if (idev->dev == dev || idev->dev_cookie == dev_cookie) {
   182				idev = ERR_PTR(-EBUSY);
   183				goto out_unlock;
   184			}
   185		}
   186	
   187		idev = kzalloc(sizeof(*idev), GFP_KERNEL);
   188		if (!idev) {
   189			ret = -ENOMEM;
   190			goto out_unlock;
   191		}
   192	
   193		/* Establish the security context */
   194		ret = iommu_device_init_user_dma(dev, (unsigned long)ictx);
   195		if (ret)
   196			goto out_free;
   197	
   198		ret = xa_alloc(&ictx->device_xa, &id, idev,
   199			       XA_LIMIT(IOMMUFD_DEVID_MIN, IOMMUFD_DEVID_MAX),
   200			       GFP_KERNEL);
   201		if (ret) {
   202			idev = ERR_PTR(ret);
   203			goto out_user_dma;
   204		}
   205	
   206		idev->ictx = ictx;
   207		idev->dev = dev;
   208		idev->dev_cookie = dev_cookie;
   209		idev->id = id;
   210		mutex_unlock(&ictx->lock);
   211	
   212		return idev;
   213	out_user_dma:
   214		iommu_device_exit_user_dma(idev->dev);
   215	out_free:
   216		kfree(idev);
   217	out_unlock:
   218		mutex_unlock(&ictx->lock);
   219		iommufd_ctx_put(ictx);
   220	
   221		return ERR_PTR(ret);
   222	}
   223	EXPORT_SYMBOL_GPL(iommufd_bind_device);
   224	

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

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