[tip:sched/core 41/47] kernel/livepatch/transition.c:419: undefined reference to `wake_up_if_idle'

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

[-- Attachment #1: Type: text/plain, Size: 4219 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
head:   b2d5b9cec60fecc72a13191c2c6c05acf60975a5
commit: 2aa45be430a031c10d5f4a5bf3329ff8413a9187 [41/47] sched,livepatch: Use wake_up_if_idle()
config: x86_64-randconfig-a004-20211012 (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/tip/tip.git/commit/?id=2aa45be430a031c10d5f4a5bf3329ff8413a9187
        git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
        git fetch --no-tags tip sched/core
        git checkout 2aa45be430a031c10d5f4a5bf3329ff8413a9187
        # save the attached .config to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: kernel/livepatch/transition.o: in function `klp_try_complete_transition':
>> kernel/livepatch/transition.c:419: undefined reference to `wake_up_if_idle'


vim +419 kernel/livepatch/transition.c

   376	
   377	/*
   378	 * Try to switch all remaining tasks to the target patch state by walking the
   379	 * stacks of sleeping tasks and looking for any to-be-patched or
   380	 * to-be-unpatched functions.  If such functions are found, the task can't be
   381	 * switched yet.
   382	 *
   383	 * If any tasks are still stuck in the initial patch state, schedule a retry.
   384	 */
   385	void klp_try_complete_transition(void)
   386	{
   387		unsigned int cpu;
   388		struct task_struct *g, *task;
   389		struct klp_patch *patch;
   390		bool complete = true;
   391	
   392		WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED);
   393	
   394		/*
   395		 * Try to switch the tasks to the target patch state by walking their
   396		 * stacks and looking for any to-be-patched or to-be-unpatched
   397		 * functions.  If such functions are found on a stack, or if the stack
   398		 * is deemed unreliable, the task can't be switched yet.
   399		 *
   400		 * Usually this will transition most (or all) of the tasks on a system
   401		 * unless the patch includes changes to a very common function.
   402		 */
   403		read_lock(&tasklist_lock);
   404		for_each_process_thread(g, task)
   405			if (!klp_try_switch_task(task))
   406				complete = false;
   407		read_unlock(&tasklist_lock);
   408	
   409		/*
   410		 * Ditto for the idle "swapper" tasks.
   411		 */
   412		cpus_read_lock();
   413		for_each_possible_cpu(cpu) {
   414			task = idle_task(cpu);
   415			if (cpu_online(cpu)) {
   416				if (!klp_try_switch_task(task)) {
   417					complete = false;
   418					/* Make idle task go through the main loop. */
 > 419					wake_up_if_idle(cpu);
   420				}
   421			} else if (task->patch_state != klp_target_state) {
   422				/* offline idle tasks can be switched immediately */
   423				clear_tsk_thread_flag(task, TIF_PATCH_PENDING);
   424				task->patch_state = klp_target_state;
   425			}
   426		}
   427		cpus_read_unlock();
   428	
   429		if (!complete) {
   430			if (klp_signals_cnt && !(klp_signals_cnt % SIGNALS_TIMEOUT))
   431				klp_send_signals();
   432			klp_signals_cnt++;
   433	
   434			/*
   435			 * Some tasks weren't able to be switched over.  Try again
   436			 * later and/or wait for other methods like kernel exit
   437			 * switching.
   438			 */
   439			schedule_delayed_work(&klp_transition_work,
   440					      round_jiffies_relative(HZ));
   441			return;
   442		}
   443	
   444		/* we're done, now cleanup the data structures */
   445		patch = klp_transition_patch;
   446		klp_complete_transition();
   447	
   448		/*
   449		 * It would make more sense to free the unused patches in
   450		 * klp_complete_transition() but it is called also
   451		 * from klp_cancel_transition().
   452		 */
   453		if (!patch->enabled)
   454			klp_free_patch_async(patch);
   455		else if (patch->replace)
   456			klp_free_replaced_patches_async(patch);
   457	}
   458	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 35589 bytes --]