Hi Andrii, kernel test robot noticed the following build errors: [auto build test ERROR on tip/perf/core] [also build test ERROR on next-20240830] [cannot apply to perf-tools-next/perf-tools-next perf-tools/perf-tools linus/master acme/perf/core v6.11-rc5] [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/Andrii-Nakryiko/uprobes-revamp-uprobe-refcounting-and-lifetime-management/20240830-024135 base: tip/perf/core patch link: https://lore.kernel.org/r/20240829183741.3331213-9-andrii%40kernel.org patch subject: [PATCH v4 8/8] uprobes: switch to RCU Tasks Trace flavor for better performance config: i386-buildonly-randconfig-004-20240830 (https://download.01.org/0day-ci/archive/20240831/202408310130.t9EBKteQ-lkp@xxxxxxxxx/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240831/202408310130.t9EBKteQ-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202408310130.t9EBKteQ-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): >> kernel/events/uprobes.c:1157:2: error: call to undeclared function 'synchronize_rcu_tasks_trace'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 1157 | synchronize_rcu_tasks_trace(); | ^ kernel/events/uprobes.c:1157:2: note: did you mean 'synchronize_rcu_tasks_rude'? include/linux/rcupdate.h:206:6: note: 'synchronize_rcu_tasks_rude' declared here 206 | void synchronize_rcu_tasks_rude(void); | ^ 1 error generated. vim +/synchronize_rcu_tasks_trace +1157 kernel/events/uprobes.c 1145 1146 void uprobe_unregister_sync(void) 1147 { 1148 /* 1149 * Now that handler_chain() and handle_uretprobe_chain() iterate over 1150 * uprobe->consumers list under RCU protection without holding 1151 * uprobe->register_rwsem, we need to wait for RCU grace period to 1152 * make sure that we can't call into just unregistered 1153 * uprobe_consumer's callbacks anymore. If we don't do that, fast and 1154 * unlucky enough caller can free consumer's memory and cause 1155 * handler_chain() or handle_uretprobe_chain() to do an use-after-free. 1156 */ > 1157 synchronize_rcu_tasks_trace(); 1158 } 1159 EXPORT_SYMBOL_GPL(uprobe_unregister_sync); 1160 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki