Messages in this thread | | | Date | Sun, 19 Dec 2021 12:29:37 +0000 | From | Wei Liu <> | Subject | Re: [hyperv:hyperv-next 4/5] drivers/hv/vmbus_drv.c:2082:29: warning: shift count >= width of type |
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On Sat, Dec 18, 2021 at 06:20:43PM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git hyperv-next > head: 19fd7ca00201c0525452dcf5a490e4b01674ef4c > commit: 6327882f7b4a476ea902de4bee5657f1028d6859 [4/5] scsi: storvsc: Add Isolation VM support for storvsc driver > config: x86_64-randconfig-a013-20211216 (https://download.01.org/0day-ci/archive/20211218/202112181827.o3X7GmHz-lkp@intel.com/config) > compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4c9e31a4814592bbda7153833e46728dc7b21100) > 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://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/commit/?id=6327882f7b4a476ea902de4bee5657f1028d6859 > git remote add hyperv https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git > git fetch --no-tags hyperv hyperv-next > git checkout 6327882f7b4a476ea902de4bee5657f1028d6859 > # save the config file to linux build tree > mkdir build_dir > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/hv/ > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> > > All warnings (new ones prefixed by >>): > > >> drivers/hv/vmbus_drv.c:2082:29: warning: shift count >= width of type [-Wshift-count-overflow] > static u64 vmbus_dma_mask = DMA_BIT_MASK(64); > ^~~~~~~~~~~~~~~~ > include/linux/dma-mapping.h:76:54: note: expanded from macro 'DMA_BIT_MASK' > #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) > ^ ~~~
I don't think there is anything wrong with the code. When n is 64 the problematic expression is not evaluated.
Wei.
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