Re: [PATCH v2 6/8] vdpa_sim: use kthread worker

kernel test robot
2023-03-05T11:22:31Z

Hi Stefano,

I love your patch! Perhaps something to improve:

[auto build test WARNING on mst-vhost/linux-next]
[also build test WARNING on linus/master next-20230303]
[cannot apply to v6.2]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Stefano-Garzarella/vdpa-add-bind_mm-unbind_mm-callbacks/20230302-193850
base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link: https://lore.kernel.org/r/20230302113421.174582-7-sgarzare%40redhat.com
patch subject: [PATCH v2 6/8] vdpa_sim: use kthread worker
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20230305/202303051841.bPAIzJRy-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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
# https://github.com/intel-lab-lkp/linux/commit/5b2107457ac0e7b1bb0aa3635ebf13b02e82bb78
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefano-Garzarella/vdpa-add-bind_mm-unbind_mm-callbacks/20230302-193850
git checkout 5b2107457ac0e7b1bb0aa3635ebf13b02e82bb78
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/net/wireless/ath/ath10k/ drivers/vdpa/vdpa_sim/ fs/erofs/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303051841.bPAIzJRy-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:166:6: warning: variable 'dev' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (IS_ERR(vdpasim->worker))
^~~~~~~~~~~~~~~~~~~~~~~
drivers/vdpa/vdpa_sim/vdpa_sim.c:213:13: note: uninitialized use occurs here
put_device(dev);
^~~
drivers/vdpa/vdpa_sim/vdpa_sim.c:166:2: note: remove the 'if' if its condition is always false
if (IS_ERR(vdpasim->worker))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/vdpa/vdpa_sim/vdpa_sim.c:132:20: note: initialize the variable 'dev' to silence this warning
struct device *dev;
^
= NULL
1 warning generated.

vim +166 drivers/vdpa/vdpa_sim/vdpa_sim.c

125
126 struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
127 const struct vdpa_dev_set_config *config)
128 {
129 const struct vdpa_config_ops *ops;
130 struct vdpa_device *vdpa;
131 struct vdpasim *vdpasim;
132 struct device *dev;
133 int i, ret = -ENOMEM;
134
135 if (!dev_attr->alloc_size)
136 return ERR_PTR(-EINVAL);
137
138 if (config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {
139 if (config->device_features &
140 ~dev_attr->supported_features)
141 return ERR_PTR(-EINVAL);
142 dev_attr->supported_features =
143 config->device_features;
144 }
145
146 if (batch_mapping)
147 ops = &vdpasim_batch_config_ops;
148 else
149 ops = &vdpasim_config_ops;
150
151 vdpa = __vdpa_alloc_device(NULL, ops,
152 dev_attr->ngroups, dev_attr->nas,
153 dev_attr->alloc_size,
154 dev_attr->name, false);
155 if (IS_ERR(vdpa)) {
156 ret = PTR_ERR(vdpa);
157 goto err_alloc;
158 }
159
160 vdpasim = vdpa_to_sim(vdpa);
161 vdpasim->dev_attr = *dev_attr;
162
163 kthread_init_work(&vdpasim->work, vdpasim_work_fn);
164 vdpasim->worker = kthread_create_worker(0, "vDPA sim worker: %s",
165 dev_attr->name);
> 166 if (IS_ERR(vdpasim->worker))
167 goto err_iommu;
168
169 spin_lock_init(&vdpasim->lock);
170 spin_lock_init(&vdpasim->iommu_lock);
171
172 dev = &vdpasim->vdpa.dev;
173 dev->dma_mask = &dev->coherent_dma_mask;
174 if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)))
175 goto err_iommu;
176 vdpasim->vdpa.mdev = dev_attr->mgmt_dev;
177
178 vdpasim->config = kzalloc(dev_attr->config_size, GFP_KERNEL);
179 if (!vdpasim->config)
180 goto err_iommu;
181
182 vdpasim->vqs = kcalloc(dev_attr->nvqs, sizeof(struct vdpasim_virtqueue),
183 GFP_KERNEL);
184 if (!vdpasim->vqs)
185 goto err_iommu;
186
187 vdpasim->iommu = kmalloc_array(vdpasim->dev_attr.nas,
188 sizeof(*vdpasim->iommu), GFP_KERNEL);
189 if (!vdpasim->iommu)
190 goto err_iommu;
191
192 vdpasim->iommu_pt = kmalloc_array(vdpasim->dev_attr.nas,
193 sizeof(*vdpasim->iommu_pt), GFP_KERNEL);
194 if (!vdpasim->iommu_pt)
195 goto err_iommu;
196
197 for (i = 0; i < vdpasim->dev_attr.nas; i++)
198 vhost_iotlb_init(&vdpasim->iommu[i], max_iotlb_entries, 0);
199
200 vdpasim->buffer = kvmalloc(dev_attr->buffer_size, GFP_KERNEL);
201 if (!vdpasim->buffer)
202 goto err_iommu;
203
204 for (i = 0; i < dev_attr->nvqs; i++)
205 vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
206 &vdpasim->iommu_lock);
207
208 vdpasim->vdpa.dma_dev = dev;
209
210 return vdpasim;
211
212 err_iommu:
213 put_device(dev);
214 err_alloc:
215 return ERR_PTR(ret);
216 }
217 EXPORT_SYMBOL_GPL(vdpasim_create);
218

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