Re: [PATCH v3 13/13] tracing: Have persistent ring buffer print syscalls normally

[kernel test robot <lkp@intel.com>]

Hi Steven,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.18-rc1 next-20251015]
[cannot apply to trace/for-next acme/perf/core]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Make-trace_user_fault_read-exposed-to-rest-of-tracing/20251016-014059
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251015173550.225723717%40kernel.org
patch subject: [PATCH v3 13/13] tracing: Have persistent ring buffer print syscalls normally
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20251016/202510161956.5wnA6TUc-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251016/202510161956.5wnA6TUc-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510161956.5wnA6TUc-lkp@intel.com/

All errors (new ones prefixed by >>):

   kernel/trace/trace.c: In function 'print_trace_fmt':
>> kernel/trace/trace.c:4258:47: error: 'enter_syscall_print_funcs' undeclared (first use in this function)
    4258 |                             (event->funcs != &enter_syscall_print_funcs) &&
         |                                               ^~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace.c:4258:47: note: each undeclared identifier is reported only once for each function it appears in
>> kernel/trace/trace.c:4259:47: error: 'exit_syscall_print_funcs' undeclared (first use in this function)
    4259 |                             (event->funcs != &exit_syscall_print_funcs))
         |                                               ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace.c: In function 'tracer_alloc_buffers':
   kernel/trace/trace.c:11443:39: error: 'CONFIG_TRACE_SYSCALL_BUF_SIZE_DEFAULT' undeclared (first use in this function)
   11443 |         global_trace.syscall_buf_sz = CONFIG_TRACE_SYSCALL_BUF_SIZE_DEFAULT;
         |                                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/enter_syscall_print_funcs +4258 kernel/trace/trace.c

  4222	
  4223	static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
  4224	{
  4225		struct trace_array *tr = iter->tr;
  4226		struct trace_seq *s = &iter->seq;
  4227		unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
  4228		struct trace_entry *entry;
  4229		struct trace_event *event;
  4230	
  4231		entry = iter->ent;
  4232	
  4233		test_cpu_buff_start(iter);
  4234	
  4235		event = ftrace_find_event(entry->type);
  4236	
  4237		if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
  4238			if (iter->iter_flags & TRACE_FILE_LAT_FMT)
  4239				trace_print_lat_context(iter);
  4240			else
  4241				trace_print_context(iter);
  4242		}
  4243	
  4244		if (trace_seq_has_overflowed(s))
  4245			return TRACE_TYPE_PARTIAL_LINE;
  4246	
  4247		if (event) {
  4248			if (tr->trace_flags & TRACE_ITER_FIELDS)
  4249				return print_event_fields(iter, event);
  4250			/*
  4251			 * For TRACE_EVENT() events, the print_fmt is not
  4252			 * safe to use if the array has delta offsets
  4253			 * Force printing via the fields.
  4254			 */
  4255			if ((tr->text_delta)) {
  4256				/* ftrace and system call events are still OK */
  4257				if ((event->type > __TRACE_LAST_TYPE) &&
> 4258				    (event->funcs != &enter_syscall_print_funcs) &&
> 4259				    (event->funcs != &exit_syscall_print_funcs))
  4260				return print_event_fields(iter, event);
  4261			}
  4262			return event->funcs->trace(iter, sym_flags, event);
  4263		}
  4264	
  4265		trace_seq_printf(s, "Unknown type %d\n", entry->type);
  4266	
  4267		return trace_handle_return(s);
  4268	}
  4269	

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