tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.10.y-rt head: 822f2ce254f44f8e65ccb2cdbd7cf4cf2208a3ff commit: e7dc055a10416e0c6eabd518d6ed89da38eca0f1 [250/279] tracing: Merge irqflags + preemt counter, add RT bits (update) config: i386-randconfig-a005-20210216 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/com... git remote add linux-rt-devel https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git git fetch --no-tags linux-rt-devel linux-5.10.y-rt git checkout e7dc055a10416e0c6eabd518d6ed89da38eca0f1 # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Note: the linux-rt-devel/linux-5.10.y-rt HEAD 822f2ce254f44f8e65ccb2cdbd7cf4cf2208a3ff builds fine. It only hurts bisectibility. All errors (new ones prefixed by >>): kernel/trace/trace_branch.c: In function 'probe_likely_condition': 62 | trace_ctx = _tracing_gen_ctx_flags(flags); | ^~~~~~~~~ | trace_reg kernel/trace/trace_branch.c:62:2: note: each undeclared identifier is reported only once for each function it appears in kernel/trace/trace_branch.c:40:15: warning: unused variable 'pc' [-Wunused-variable] 40 | unsigned int pc; | ^~ kernel/trace/trace_branch.c: At top level: kernel/trace/trace_branch.c:205:6: warning: no previous prototype for 'ftrace_likely_update' [-Wmissing-prototypes] 205 | void ftrace_likely_update(struct ftrace_likely_data *f, int val, | ^~~~~~~~~~~~~~~~~~~~ vim +62 kernel/trace/trace_branch.c 29 30 static void 31 probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) 32 { 33 struct trace_event_call *call = &event_branch; 34 struct trace_array *tr = branch_tracer; 35 struct trace_buffer *buffer; 36 struct trace_array_cpu *data; 37 struct ring_buffer_event *event; 38 struct trace_branch *entry; 39 unsigned long flags; 40 unsigned int pc; 41 const char *p; 42 43 if (current->trace_recursion & TRACE_BRANCH_BIT) 44 return; 45 46 /* 47 * I would love to save just the ftrace_likely_data pointer, but 48 * this code can also be used by modules. Ugly things can happen 49 * if the module is unloaded, and then we go and read the 50 * pointer. This is slower, but much safer. 51 */ 52 53 if (unlikely(!tr)) 54 return; 55 56 raw_local_irq_save(flags); 57 current->trace_recursion |= TRACE_BRANCH_BIT; 58 data = this_cpu_ptr(tr->array_buffer.data); 59 if (atomic_read(&data->disabled)) 60 goto out; 61 63 buffer = tr->array_buffer.buffer; 64 event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH, 65 sizeof(*entry), trace_ctx); 66 if (!event) 67 goto out; 68 69 entry = ring_buffer_event_data(event); 70 71 /* Strip off the path, only save the file */ 72 p = f->data.file + strlen(f->data.file); 73 while (p >= f->data.file && *p != '/') 74 p--; 75 p++; 76 77 strncpy(entry->func, f->data.func, TRACE_FUNC_SIZE); 78 strncpy(entry->file, p, TRACE_FILE_SIZE); 79 entry->func[TRACE_FUNC_SIZE] = 0; 80 entry->file[TRACE_FILE_SIZE] = 0; 81 entry->constant = f->constant; 82 entry->line = f->data.line; 83 entry->correct = val == expect; 84 85 if (!call_filter_check_discard(call, entry, buffer, event)) 86 trace_buffer_unlock_commit_nostack(buffer, event); 87 88 out: 89 current->trace_recursion &= ~TRACE_BRANCH_BIT; 90 raw_local_irq_restore(flags); 91 } 92 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org