Hi Eduard, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Eduard-Zingerman/bpf_loop-inlining/20220528-075454 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: x86_64-randconfig-a013 (https://download.01.org/0day-ci/archive/20220528/202205281148.rY3lJqB4-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-1) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/05c5a11449d4e5c75ada599a71d8290bef8a5d1a git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Eduard-Zingerman/bpf_loop-inlining/20220528-075454 git checkout 05c5a11449d4e5c75ada599a71d8290bef8a5d1a # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/bpf/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): kernel/bpf/verifier.c: In function 'adjust_stack_depth_for_loop_inlining': >> kernel/bpf/verifier.c:7127:16: warning: variable 'subprog_start' set but not used [-Wunused-but-set-variable] 7127 | int i, subprog_start, subprog_end, cur_subprog = 0; | ^~~~~~~~~~~~~ vim +/subprog_start +7127 kernel/bpf/verifier.c 7117 7118 /* For all sub-programs in the program (including main) checks 7119 * insn_aux_data to see if there are bpf_loop calls that require 7120 * inlining. If such calls are found subprog stack_depth is increased 7121 * by the size of 3 registers. Reserved space would be used in the 7122 * do_misc_fixups to spill values of the R6, R7, R8 to use these 7123 * registers for loop iteration. 7124 */ 7125 static void adjust_stack_depth_for_loop_inlining(struct bpf_verifier_env *env) 7126 { > 7127 int i, subprog_start, subprog_end, cur_subprog = 0; 7128 struct bpf_subprog_info *subprog = env->subprog_info; 7129 int insn_cnt = env->prog->len; 7130 7131 subprog_start = subprog[cur_subprog].start; 7132 subprog_end = env->subprog_cnt > 1 7133 ? subprog[cur_subprog + 1].start 7134 : insn_cnt; 7135 for (i = 0; i < insn_cnt; i++) { 7136 if (fit_for_bpf_loop_inline(&env->insn_aux_data[i])) { 7137 /* reserve space for 3 registers */ 7138 subprog->stack_depth += BPF_REG_SIZE * 3; 7139 /* skip to the next subprog */ 7140 i = subprog_end - 1; 7141 } 7142 if (i == subprog_end - 1) { 7143 subprog_start = subprog_end; 7144 cur_subprog++; 7145 if (cur_subprog < env->subprog_cnt) 7146 subprog_end = subprog[cur_subprog + 1].start; 7147 } 7148 } 7149 7150 env->prog->aux->stack_depth = env->subprog_info[0].stack_depth; 7151 } 7152 -- 0-DAY CI Kernel Test Service https://01.org/lkp
