Re: [PATCH 3/5] tracing: Have tracer option be instance specific

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

Hi Steven,

kernel test robot noticed the following build errors:

[auto build test ERROR on trace/for-next]
[cannot apply to linus/master v6.18-rc4 next-20251106]
[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-Remove-dummy-options-and-flags/20251106-010511
base:   https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link:    https://lore.kernel.org/r/20251105161935.545400234%40kernel.org
patch subject: [PATCH 3/5] tracing: Have tracer option be instance specific
config: i386-buildonly-randconfig-004-20251106 (https://download.01.org/0day-ci/archive/20251106/202511062257.TSJTBQ2c-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251106/202511062257.TSJTBQ2c-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/202511062257.TSJTBQ2c-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/trace/trace.c:2174:23: error: redefinition of 'type' with a different type: 'struct trace_tracer *' vs 'struct tracer *'
    2174 |         struct trace_tracer *type = tracers->trace;
         |                              ^
   kernel/trace/trace.c:2171:47: note: previous definition is here
    2171 | static int run_tracer_selftest(struct tracer *type)
         |                                               ^
>> kernel/trace/trace.c:2174:30: error: use of undeclared identifier 'tracers'
    2174 |         struct trace_tracer *type = tracers->trace;
         |                                     ^
   kernel/trace/trace.c:5172:17: warning: variable 'trace' set but not used [-Wunused-but-set-variable]
    5172 |         struct tracer *trace;
         |                        ^
   1 warning and 2 errors generated.


vim +2174 kernel/trace/trace.c

  2170	
  2171	static int run_tracer_selftest(struct tracer *type)
  2172	{
  2173		struct trace_array *tr = &global_trace;
> 2174		struct trace_tracer *type = tracers->trace;
  2175		struct tracer_flags *saved_flags = tr->current_trace_flags;
  2176		struct tracer_flags *flags;
  2177		struct tracer *saved_tracer = tr->current_trace;
  2178		int ret;
  2179	
  2180		if (!type->selftest || tracing_selftest_disabled)
  2181			return 0;
  2182	
  2183		/*
  2184		 * If a tracer registers early in boot up (before scheduling is
  2185		 * initialized and such), then do not run its selftests yet.
  2186		 * Instead, run it a little later in the boot process.
  2187		 */
  2188		if (!selftests_can_run)
  2189			return save_selftest(type);
  2190	
  2191		if (!tracing_is_on()) {
  2192			pr_warn("Selftest for tracer %s skipped due to tracing disabled\n",
  2193				type->name);
  2194			return 0;
  2195		}
  2196	
  2197		/*
  2198		 * Run a selftest on this tracer.
  2199		 * Here we reset the trace buffer, and set the current
  2200		 * tracer to be this tracer. The tracer can then run some
  2201		 * internal tracing to verify that everything is in order.
  2202		 * If we fail, we do not register this tracer.
  2203		 */
  2204		tracing_reset_online_cpus(&tr->array_buffer);
  2205	
  2206		tr->current_trace = type;
  2207		tr->current_trace_flags = type->flags ? : type->default_flags;
  2208	

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