Hi "Toke, I love your patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Toke-H-iland-J-rgensen/bpf-Support-injecting-chain-calls-into-BPF-programs-on-load/20191005-035650 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: xtensa-allyesconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 7.4.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree GCC_VERSION=7.4.0 make.cross ARCH=xtensa If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): kernel/bpf/verifier.c: In function 'bpf_inject_chain_calls': >> kernel/bpf/verifier.c:9195:27: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] call_next[0].imm = (u32)((u64) prog_array); ^ kernel/bpf/verifier.c:9196:22: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] call_next[1].imm = ((u64) prog_array) >> 32; ^ vim +9195 kernel/bpf/verifier.c 9156 9157 static int bpf_inject_chain_calls(struct bpf_verifier_env *env) 9158 { 9159 struct bpf_prog *prog = env->prog; 9160 struct bpf_insn *insn = prog->insnsi; 9161 int i, cnt, delta = 0, ret = -ENOMEM; 9162 const int insn_cnt = prog->len; 9163 struct bpf_array *prog_array; 9164 struct bpf_prog *new_prog; 9165 size_t array_size; 9166 9167 struct bpf_insn call_next[] = { 9168 BPF_LD_IMM64(BPF_REG_2, 0), 9169 /* Save real return value for later */ 9170 BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), 9171 /* First try tail call with index ret+1 */ 9172 BPF_MOV64_REG(BPF_REG_3, BPF_REG_0), 9173 BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 1), 9174 BPF_RAW_INSN(BPF_JMP | BPF_TAIL_CALL, 0, 0, 0, 0), 9175 /* If that doesn't work, try with index 0 (wildcard) */ 9176 BPF_MOV64_IMM(BPF_REG_3, 0), 9177 BPF_RAW_INSN(BPF_JMP | BPF_TAIL_CALL, 0, 0, 0, 0), 9178 /* Restore saved return value and exit */ 9179 BPF_MOV64_REG(BPF_REG_0, BPF_REG_6), 9180 BPF_EXIT_INSN() 9181 }; 9182 9183 if (prog->aux->chain_progs) 9184 return 0; 9185 9186 array_size = sizeof(*prog_array) + BPF_NUM_CHAIN_SLOTS * sizeof(void*); 9187 prog_array = bpf_map_area_alloc(array_size, NUMA_NO_NODE); 9188 9189 if (!prog_array) 9190 goto out_err; 9191 9192 prog_array->elem_size = sizeof(void*); 9193 prog_array->map.max_entries = BPF_NUM_CHAIN_SLOTS; 9194 > 9195 call_next[0].imm = (u32)((u64) prog_array); 9196 call_next[1].imm = ((u64) prog_array) >> 32; 9197 9198 for (i = 0; i < insn_cnt; i++, insn++) { 9199 if (insn->code != (BPF_JMP | BPF_EXIT)) 9200 continue; 9201 9202 cnt = ARRAY_SIZE(call_next); 9203 9204 new_prog = bpf_patch_insn_data(env, i+delta, call_next, cnt); 9205 if (!new_prog) { 9206 goto out_err; 9207 } 9208 9209 delta += cnt - 1; 9210 env->prog = prog = new_prog; 9211 insn = new_prog->insnsi + i + delta; 9212 } 9213 9214 /* If we chain call into other programs, we cannot make any assumptions 9215 * since they can be replaced dynamically during runtime. 9216 */ 9217 prog->cb_access = 1; 9218 env->prog->aux->stack_depth = MAX_BPF_STACK; 9219 env->prog->aux->max_pkt_offset = MAX_PACKET_OFF; 9220 9221 prog->aux->chain_progs = prog_array; 9222 return 0; 9223 9224 out_err: 9225 bpf_map_area_free(prog_array); 9226 return ret; 9227 } 9228 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
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