[kbuild-all] drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:236:9: warning: The left expression of the compound assignment is an uninitialized value. The computed value will also be garbage [clang-analyzer-core.uninitialized.Assign]

tree: https://github.com/0day-ci/linux/commits/Arunpravin/Enable-buddy-memory-m... head: 71b3775a5ce7b59e8c5292ae438284e8569c9e9f commit: 71b3775a5ce7b59e8c5292ae438284e8569c9e9f Add drm buddy manager support to amdgpu driver date: 7 weeks ago config: riscv-randconfig-c006-20210927 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project dc6e8dfdfe7efecfda318d43a06fae18b40eb498) 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/0day-ci/linux/commit/71b3775a5ce7b59e8c5292ae438284e85... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Arunpravin/Enable-buddy-memory-manager-support/20210921-032602 git checkout 71b3775a5ce7b59e8c5292ae438284e8569c9e9f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; clang-analyzer warnings: (new ones prefixed by >>) usage += amdgpu_vram_mgr_vis_size(adev, block); ~~~~~ ^ drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:227:2: note: 'usage' declared without an initial value u64 usage; ^~~~~~~~~ drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:236:9: note: The left expression of the compound assignment is an uninitialized value. The computed value will also be garbage usage += amdgpu_vram_mgr_vis_size(adev, block); ~~~~~ ^ return usage; ^ ~~~~~ vim +236 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 3c848bb38aca1f Christian König 2017-08-07 212 5e9244ff585239 Michel Dänzer 2018-06-12 213 /** ddc21af4d0f37f Michel Dänzer 2018-07-11 214 * amdgpu_vram_mgr_bo_visible_size - CPU visible BO size 5e9244ff585239 Michel Dänzer 2018-06-12 215 * 5e9244ff585239 Michel Dänzer 2018-06-12 216 * @bo: &amdgpu_bo buffer object (must be in VRAM) 5e9244ff585239 Michel Dänzer 2018-06-12 217 * 5e9244ff585239 Michel Dänzer 2018-06-12 218 * Returns: ddc21af4d0f37f Michel Dänzer 2018-07-11 219 * How much of the given &amdgpu_bo buffer object lies in CPU visible VRAM. 5e9244ff585239 Michel Dänzer 2018-06-12 220 */ ddc21af4d0f37f Michel Dänzer 2018-07-11 221 u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo) 5e9244ff585239 Michel Dänzer 2018-06-12 222 { 7303b39e46b2f5 Michel Dänzer 2018-06-14 223 struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); cb1c81467af355 Christian König 2021-04-30 224 struct ttm_resource *res = bo->tbo.resource; 71b3775a5ce7b5 Arunpravin 2021-09-21 225 struct amdgpu_vram_mgr_node *vnode = to_amdgpu_vram_mgr_node(res); 71b3775a5ce7b5 Arunpravin 2021-09-21 226 struct drm_buddy_block *block; ddc21af4d0f37f Michel Dänzer 2018-07-11 227 u64 usage; 5e9244ff585239 Michel Dänzer 2018-06-12 228 9735bf1930e658 Michel Dänzer 2018-06-15 229 if (amdgpu_gmc_vram_full_visible(&adev->gmc)) ddc21af4d0f37f Michel Dänzer 2018-07-11 230 return amdgpu_bo_size(bo); 7303b39e46b2f5 Michel Dänzer 2018-06-14 231 cb1c81467af355 Christian König 2021-04-30 232 if (res->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT) ddc21af4d0f37f Michel Dänzer 2018-07-11 233 return 0; 7303b39e46b2f5 Michel Dänzer 2018-06-14 234 71b3775a5ce7b5 Arunpravin 2021-09-21 235 list_for_each_entry(block, &vnode->blocks, link) 71b3775a5ce7b5 Arunpravin 2021-09-21 @236 usage += amdgpu_vram_mgr_vis_size(adev, block); 7303b39e46b2f5 Michel Dänzer 2018-06-14 237 7303b39e46b2f5 Michel Dänzer 2018-06-14 @238 return usage; 5e9244ff585239 Michel Dänzer 2018-06-12 239 } 5e9244ff585239 Michel Dänzer 2018-06-12 240 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org