Hi Qi, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v5.12-rc3 next-20210317] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Qi-Liu/drivers-perf-convert-sysf... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1df27313f50a57497c1faeb6a6ae4ca939c85a7d config: arm64-randconfig-r003-20210317 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 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://github.com/0day-ci/linux/commit/81a69a2f7fa73d0c41d699d6c6993c259... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Qi-Liu/drivers-perf-convert-sysfs-sprintf-snprintf-scnprintf-to-sysfs_emit/20210317-174750 git checkout 81a69a2f7fa73d0c41d699d6c6993c2594001241 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 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 >>): drivers/perf/arm-ccn.c: In function 'arm_ccn_pmu_event_show': 345 | res += sysfs_emit(buf + res, res, ",xp=?,vc=?"); | ^~~ | | | ssize_t {aka long int} In file included from include/linux/kobject.h:20, from include/linux/irqdesc.h:6, from include/linux/irq.h:584, from include/asm-generic/hardirq.h:17, from arch/arm64/include/asm/hardirq.h:17, from include/linux/hardirq.h:10, from include/linux/interrupt.h:11, from drivers/perf/arm-ccn.c:10: include/linux/sysfs.h:335:39: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'long int'} 335 | int sysfs_emit(char *buf, const char *fmt, ...); | ~~~~~~~~~~~~^~~ vim +/sysfs_emit +345 drivers/perf/arm-ccn.c 274 275 #define CCN_EVENT_ATTR(_name) \ 276 __ATTR(_name, S_IRUGO, arm_ccn_pmu_event_show, NULL) 277 278 /* 279 * Events defined in TRM for MN, HN-I and SBSX are actually watchpoints set on 280 * their ports in XP they are connected to. For the sake of usability they are 281 * explicitly defined here (and translated into a relevant watchpoint in 282 * arm_ccn_pmu_event_init()) so the user can easily request them without deep 283 * knowledge of the flit format. 284 */ 285 286 #define CCN_EVENT_MN(_name, _def, _mask) { .attr = CCN_EVENT_ATTR(mn_##_name), \ 287 .type = CCN_TYPE_MN, .event = CCN_EVENT_WATCHPOINT, \ 288 .num_ports = CCN_NUM_XP_PORTS, .num_vcs = CCN_NUM_VCS, \ 289 .def = _def, .mask = _mask, } 290 291 #define CCN_EVENT_HNI(_name, _def, _mask) { \ 292 .attr = CCN_EVENT_ATTR(hni_##_name), .type = CCN_TYPE_HNI, \ 293 .event = CCN_EVENT_WATCHPOINT, .num_ports = CCN_NUM_XP_PORTS, \ 294 .num_vcs = CCN_NUM_VCS, .def = _def, .mask = _mask, } 295 296 #define CCN_EVENT_SBSX(_name, _def, _mask) { \ 297 .attr = CCN_EVENT_ATTR(sbsx_##_name), .type = CCN_TYPE_SBSX, \ 298 .event = CCN_EVENT_WATCHPOINT, .num_ports = CCN_NUM_XP_PORTS, \ 299 .num_vcs = CCN_NUM_VCS, .def = _def, .mask = _mask, } 300 301 #define CCN_EVENT_HNF(_name, _event) { .attr = CCN_EVENT_ATTR(hnf_##_name), \ 302 .type = CCN_TYPE_HNF, .event = _event, } 303 304 #define CCN_EVENT_XP(_name, _event) { .attr = CCN_EVENT_ATTR(xp_##_name), \ 305 .type = CCN_TYPE_XP, .event = _event, \ 306 .num_ports = CCN_NUM_XP_PORTS, .num_vcs = CCN_NUM_VCS, } 307 308 /* 309 * RN-I & RN-D (RN-D = RN-I + DVM) nodes have different type ID depending 310 * on configuration. One of them is picked to represent the whole group, 311 * as they all share the same event types. 312 */ 313 #define CCN_EVENT_RNI(_name, _event) { .attr = CCN_EVENT_ATTR(rni_##_name), \ 314 .type = CCN_TYPE_RNI_3P, .event = _event, } 315 316 #define CCN_EVENT_SBAS(_name, _event) { .attr = CCN_EVENT_ATTR(sbas_##_name), \ 317 .type = CCN_TYPE_SBAS, .event = _event, } 318 319 #define CCN_EVENT_CYCLES(_name) { .attr = CCN_EVENT_ATTR(_name), \ 320 .type = CCN_TYPE_CYCLES } 321 322 323 static ssize_t arm_ccn_pmu_event_show(struct device *dev, 324 struct device_attribute *attr, char *buf) 325 { 326 struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev)); 327 struct arm_ccn_pmu_event *event = container_of(attr, 328 struct arm_ccn_pmu_event, attr); 329 ssize_t res; 330 331 res = sysfs_emit(buf, "type=0x%x", event->type); 332 if (event->event) 333 res += sysfs_emit_at(buf + res, res, ",event=0x%x", 334 event->event); 335 if (event->def) 336 res += sysfs_emit_at(buf + res, res, ",%s", event->def); 337 if (event->mask) 338 res += sysfs_emit_at(buf + res, res, ",mask=0x%x", event->mask); 339 340 /* Arguments required by an event */ 341 switch (event->type) { 342 case CCN_TYPE_CYCLES: 343 break; 344 case CCN_TYPE_XP: 346 if (event->event == CCN_EVENT_WATCHPOINT) 347 res += sysfs_emit_at(buf + res, res, 348 ",port=?,dir=?,cmp_l=?,cmp_h=?,mask=?"); 349 else 350 res += sysfs_emit_at(buf + res, res, ",bus=?"); 351 352 break; 353 case CCN_TYPE_MN: 354 res += sysfs_emit_at(buf + res, res, ",node=%d", ccn->mn_id); 355 break; 356 default: 357 res += sysfs_emit_at(buf + res, res, ",node=?"); 358 break; 359 } 360 361 res += sysfs_emit_at(buf + res, res, "\n"); 362 363 return res; 364 } 365 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org