tree: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next head: 18956295fea61e6a08a15d829b06e744830ae236 commit: b32ac463cb59e758b4560260fd168a2b4ea6e81a [114/140] scsi: sg: NO_DXFER move to/from kernel buffers config: x86_64-randconfig-r015-20210308 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cd9a69289c7825d54450cb6829fef2c8e0f1963a) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/commit/?id=b... git remote add mkp-scsi https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git git fetch --no-tags mkp-scsi for-next git checkout b32ac463cb59e758b4560260fd168a2b4ea6e81a # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): bio = sg_mk_kern_bio(num_sgat - k); ^ drivers/scsi/sg.c:2889:7: note: initialize the variable 'k' to silence this warning int k, ln; ^ = 0 1 warning generated. vim +/k +2902 drivers/scsi/sg.c 2878 2879 /* 2880 * Setup to move data between kernel buffers managed by this driver and a SCSI device. Note that 2881 * there is no corresponding 'unmap' call as is required by blk_rq_map_user() . Uses a single 2882 * bio with an expanded appended bvec if necessary. 2883 */ 2884 static int 2885 sg_rq_map_kern(struct sg_request *srp, struct request_queue *q, struct request *rqq, int rw_ind) 2886 { 2887 struct sg_scatter_hold *schp = &srp->sgat_h; 2888 struct bio *bio; 2889 int k, ln; 2890 int op_flags = 0; 2891 int num_sgat = schp->num_sgat; 2892 int dlen = schp->dlen; 2893 int pg_sz = 1 << (PAGE_SHIFT + schp->page_order); 2894 int num_segs = (1 << schp->page_order) * num_sgat; 2895 int res = 0; 2896 2897 SG_LOG(4, srp->parentfp, "%s: dlen=%d, pg_sz=%d\n", __func__, dlen, pg_sz); 2898 if (num_sgat <= 0) 2899 return 0; 2900 if (rw_ind == WRITE) 2901 op_flags = REQ_SYNC | REQ_IDLE; 2903 if (!bio) 2904 return -ENOMEM; 2905 bio->bi_opf = req_op(rqq) | op_flags; 2906 2907 for (k = 0; k < num_sgat && dlen > 0; ++k, dlen -= ln) { 2908 ln = min_t(int, dlen, pg_sz); 2909 if (bio_add_pc_page(q, bio, schp->pages[k], ln, 0) < ln) { 2910 bio_put(bio); 2911 return -EINVAL; 2912 } 2913 } 2914 res = blk_rq_append_bio(rqq, &bio); 2915 if (unlikely(res)) 2916 bio_put(bio); 2917 else 2918 rqq->nr_phys_segments = num_segs; 2919 return res; 2920 } 2921 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org