Re: [PATCH v12 01/15] iommu: Introduce attach/detach_pasid_table API

From: kernel test robot
Date: Mon Nov 16 2020 - 10:14:55 EST


Hi Eric,

I love your patch! Perhaps something to improve:

[auto build test WARNING on iommu/next]
[also build test WARNING on linus/master v5.10-rc4 next-20201116]
[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]

url: https://github.com/0day-ci/linux/commits/Eric-Auger/SMMUv3-Nested-Stage-Setup-IOMMU-part/20201116-185039
base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: arm64-randconfig-r034-20201115 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c044709b8fbea2a9a375e4173a6bd735f6866c0c)
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 arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/0day-ci/linux/commit/54be9a9e014a566f9c7640da201c24cfb1eda06e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Eric-Auger/SMMUv3-Nested-Stage-Setup-IOMMU-part/20201116-185039
git checkout 54be9a9e014a566f9c7640da201c24cfb1eda06e
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64

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/iommu.c:2225:34: warning: overlapping comparisons always evaluate to false [-Wtautological-overlap-compare]
if (pasid_table_data.config < 1 && pasid_table_data.config > 3)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.

vim +2225 drivers/iommu/iommu.c

2182
2183 int iommu_uapi_attach_pasid_table(struct iommu_domain *domain,
2184 void __user *uinfo)
2185 {
2186 struct iommu_pasid_table_config pasid_table_data = { 0 };
2187 u32 minsz;
2188
2189 if (unlikely(!domain->ops->attach_pasid_table))
2190 return -ENODEV;
2191
2192 /*
2193 * No new spaces can be added before the variable sized union, the
2194 * minimum size is the offset to the union.
2195 */
2196 minsz = offsetof(struct iommu_pasid_table_config, vendor_data);
2197
2198 /* Copy minsz from user to get flags and argsz */
2199 if (copy_from_user(&pasid_table_data, uinfo, minsz))
2200 return -EFAULT;
2201
2202 /* Fields before the variable size union are mandatory */
2203 if (pasid_table_data.argsz < minsz)
2204 return -EINVAL;
2205
2206 /* PASID and address granu require additional info beyond minsz */
2207 if (pasid_table_data.version != PASID_TABLE_CFG_VERSION_1)
2208 return -EINVAL;
2209 if (pasid_table_data.format == IOMMU_PASID_FORMAT_SMMUV3 &&
2210 pasid_table_data.argsz <
2211 offsetofend(struct iommu_pasid_table_config, vendor_data.smmuv3))
2212 return -EINVAL;
2213
2214 /*
2215 * User might be using a newer UAPI header which has a larger data
2216 * size, we shall support the existing flags within the current
2217 * size. Copy the remaining user data _after_ minsz but not more
2218 * than the current kernel supported size.
2219 */
2220 if (copy_from_user((void *)&pasid_table_data + minsz, uinfo + minsz,
2221 min_t(u32, pasid_table_data.argsz, sizeof(pasid_table_data)) - minsz))
2222 return -EFAULT;
2223
2224 /* Now the argsz is validated, check the content */
> 2225 if (pasid_table_data.config < 1 && pasid_table_data.config > 3)
2226 return -EINVAL;
2227
2228 return domain->ops->attach_pasid_table(domain, &pasid_table_data);
2229 }
2230 EXPORT_SYMBOL_GPL(iommu_uapi_attach_pasid_table);
2231

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

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