tree: https://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git ftrace/fgraph-multi head: 978dc256bd4d08df876d58b4fa01ba4cb3926242 commit: be13406cc12900ea57d62a9afcc33c4e11a1993f [34/40] function_graph: Have the instances use their own ftrace_ops for filtering config: i386-randconfig-r035-20210416 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git/c... git remote add trace https://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git git fetch --no-tags trace ftrace/fgraph-multi git checkout be13406cc12900ea57d62a9afcc33c4e11a1993f # save the attached .config to linux build tree make W=1 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; All warnings (new ones prefixed by >>): kernel/trace/fgraph.c:481:15: warning: no previous prototype for 'ftrace_return_to_handler' [-Wmissing-prototypes] 481 | unsigned long ftrace_return_to_handler(unsigned long frame_pointer) | ^~~~~~~~~~~~~~~~~~~~~~~~ kernel/trace/fgraph.c: In function 'ftrace_return_to_handler': kernel/trace/fgraph.c:483:27: warning: variable 'ret_stack' set but not used [-Wunused-but-set-variable] 483 | struct ftrace_ret_stack *ret_stack; | ^~~~~~~~~ kernel/trace/fgraph.c: At top level: 613 | void fgraph_init_ops(struct ftrace_ops *dst_ops, | ^~~~~~~~~~~~~~~ kernel/trace/fgraph.c:633:6: warning: no previous prototype for 'ftrace_graph_sleep_time_control' [-Wmissing-prototypes] 633 | void ftrace_graph_sleep_time_control(bool enable) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/trace/fgraph.c:645:46: error: initialization of 'trace_func_graph_ret_t' {aka 'void (*)(struct ftrace_graph_ret *, struct fgraph_ops *)'} from incompatible pointer type 'void (*)(struct ftrace_graph_ret *)' [-Werror=incompatible-pointer-types] 645 | trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph; | ^~~~~~~~~~~~~~~~~ kernel/trace/fgraph.c: In function 'unregister_ftrace_graph': kernel/trace/fgraph.c:924:23: error: assignment to 'trace_func_graph_ret_t' {aka 'void (*)(struct ftrace_graph_ret *, struct fgraph_ops *)'} from incompatible pointer type 'void (*)(struct ftrace_graph_ret *)' [-Werror=incompatible-pointer-types] 924 | ftrace_graph_return = ftrace_stub_graph; | ^ cc1: some warnings being treated as errors vim +/fgraph_init_ops +613 kernel/trace/fgraph.c 612 614 struct ftrace_ops *src_ops) 615 { 616 dst_ops->func = ftrace_stub; 617 dst_ops->flags = FTRACE_OPS_FL_PID | FTRACE_OPS_FL_STUB; 618 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org