Re: [PATCH v11 1/4] trace: Add trace any kernel object

From: Jeff Xie
Date: Fri Jun 03 2022 - 22:20:16 EST

Hi Nathan,

On Fri, Jun 3, 2022 at 11:37 PM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> On Fri, Jun 03, 2022 at 09:48:07AM +0800, Jeff Xie wrote:
> > Hi lkp,
> >
> > On Fri, Jun 3, 2022 at 5:12 AM kernel test robot <lkp@xxxxxxxxx> wrote:
> > >
> > > Hi Jeff,
> > >
> > > Thank you for the patch! Perhaps something to improve:
> > >
> > > [auto build test WARNING on b39181f7c6907dc66ff937b74758671fa6ba430c]
> > >
> > > url: https://github.com/intel-lab-lkp/linux/commits/Jeff-Xie/trace-Introduce-objtrace-trigger-to-trace-the-kernel-object/20220603-004723
> > > base: b39181f7c6907dc66ff937b74758671fa6ba430c
> > > config: i386-randconfig-a013 (https://download.01.org/0day-ci/archive/20220603/202206030515.4lqqkb3W-lkp@xxxxxxxxx/config)
> > > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project b364c76683f8ef241025a9556300778c07b590c2)
> > > 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/intel-lab-lkp/linux/commit/765253f020469f94856aedc5a3fe5444e1e8f4e8
> > > git remote add linux-review https://github.com/intel-lab-lkp/linux
> > > git fetch --no-tags linux-review Jeff-Xie/trace-Introduce-objtrace-trigger-to-trace-the-kernel-object/20220603-004723
> > > git checkout 765253f020469f94856aedc5a3fe5444e1e8f4e8
> > > # save the config file
> > > mkdir build_dir && cp config build_dir/.config
> > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/qxl/ kernel/trace/
> > >
> > > 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/trace/trace_object.c:336:61: warning: format specifies type 'long' but the argument has type 'unsigned int' [-Wformat]
> > > pr_err("the size of the %s should be:%ld\n", field->name, sizeof(void *));
> > > ~~~ ^~~~~~~~~~~~~~
> > > %u
> >
> > I will double check it ,the sizeof(void *) on x86_64 is type ‘long
> > unsigned int’.
>
> Per Documentation/core-api/printk-formats.rst, sizeof returns size_t,
> which should use the %zu specifier.

This is great, Thank you for your reminder ;-)

> Cheers,
> Nathan
>
> > > include/linux/printk.h:489:33: note: expanded from macro 'pr_err'
> > > printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
> > > ~~~ ^~~~~~~~~~~
> > > include/linux/printk.h:446:60: note: expanded from macro 'printk'
> > > #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
> > > ~~~ ^~~~~~~~~~~
> > > include/linux/printk.h:418:19: note: expanded from macro 'printk_index_wrap'
> > > _p_func(_fmt, ##__VA_ARGS__); \
> > > ~~~~ ^~~~~~~~~~~
> > > 1 warning generated.
> > >
> > >
> > > vim +336 kernel/trace/trace_object.c
> > >
> > > 297
> > > 298 static int
> > > 299 event_object_trigger_parse(struct event_command *cmd_ops,
> > > 300 struct trace_event_file *file,
> > > 301 char *glob, char *cmd, char *param_and_filter)
> > > 302 {
> > > 303 struct event_trigger_data *trigger_data;
> > > 304 struct objtrace_trigger_data *obj_data;
> > > 305 struct ftrace_event_field *field;
> > > 306 char *objtrace_cmd, *arg;
> > > 307 char *param, *filter;
> > > 308 int ret;
> > > 309 bool remove;
> > > 310
> > > 311 remove = event_trigger_check_remove(glob);
> > > 312
> > > 313 /*
> > > 314 * separate the param and the filter:
> > > 315 * objtrace:add:OBJ[:COUNT] [if filter]
> > > 316 */
> > > 317 ret = event_trigger_separate_filter(param_and_filter, &param, &filter, true);
> > > 318 if (ret)
> > > 319 return ret;
> > > 320
> > > 321 objtrace_cmd = strsep(&param, ":");
> > > 322 if (!objtrace_cmd || strcmp(objtrace_cmd, OBJTRACE_CMD_ADD)) {
> > > 323 pr_err("error objtrace command\n");
> > > 324 return -EINVAL;
> > > 325 }
> > > 326
> > > 327 arg = strsep(&param, ":");
> > > 328 if (!arg)
> > > 329 return -EINVAL;
> > > 330
> > > 331 field = trace_find_event_field(file->event_call, arg);
> > > 332 if (!field)
> > > 333 return -EINVAL;
> > > 334
> > > 335 if (field->size != sizeof(void *)) {
> > > > 336 pr_err("the size of the %s should be:%ld\n", field->name, sizeof(void *));
> > > 337 return -EINVAL;
> > > 338 }
> > > 339
> > > 340 if (remove && !field_exist(file, cmd_ops, field->name))
> > > 341 return -ENOENT;
> > > 342
> > > 343 obj_data = kzalloc(sizeof(*obj_data), GFP_KERNEL);
> > > 344 if (!obj_data)
> > > 345 return -ENOMEM;
> > > 346
> > > 347 obj_data->field = field;
> > > 348 obj_data->tr = file->tr;
> > > 349 snprintf(obj_data->objtrace_cmd, OBJTRACE_CMD_LEN, objtrace_cmd);
> > > 350
> > > 351 trigger_data = event_trigger_alloc(cmd_ops, cmd, param, obj_data);
> > > 352 if (!trigger_data) {
> > > 353 kfree(obj_data);
> > > 354 return -ENOMEM;
> > > 355 }
> > > 356 if (remove) {
> > > 357 event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
> > > 358 kfree(obj_data);
> > > 359 kfree(trigger_data);
> > > 360 return 0;
> > > 361 }
> > > 362
> > > 363 ret = event_trigger_parse_num(param, trigger_data);
> > > 364 if (ret)
> > > 365 goto out_free;
> > > 366
> > > 367 ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
> > > 368 if (ret < 0)
> > > 369 goto out_free;
> > > 370
> > > 371 ret = event_trigger_register(cmd_ops, file, glob, trigger_data);
> > > 372 if (ret)
> > > 373 goto out_free;
> > > 374
> > > 375 return ret;
> > > 376
> > > 377 out_free:
> > > 378 event_trigger_reset_filter(cmd_ops, trigger_data);
> > > 379 kfree(obj_data);
> > > 380 kfree(trigger_data);
> > > 381 return ret;
> > > 382 }
> > > 383
> > >
> > > --
> > > 0-DAY CI Kernel Test Service
> > > https://01.org/lkp
> >
> > Thanks,
> > JeffXie
> >
Thanks,
JeffXie