[linux-next:master 3092/3266] kernel/smpboot.c:449 cpu_wait_death() error: uninitialized symbol 'oldstate'.

[linux-next:master 3092/3266] kernel/smpboot.c:449 cpu_wait_death() error: uninitialized symbol 'oldstate'.

[Dan Carpenter]

Hi Uros,

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   b5d939c951865f6fc229094e84b77c9a9e0ed0c7
commit: 2d1e07c7534c14e56ac3818fa24e7c1643a9b1dc [3092/3266] smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death
config: i386-randconfig-m021 (https://download.01.org/0day-ci/archive/20220825/202208251909.gOzRDLgL-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
kernel/smpboot.c:449 cpu_wait_death() error: uninitialized symbol 'oldstate'.

vim +/oldstate +449 kernel/smpboot.c

8038dad7e88858 Paul E. McKenney 2015-02-25  425  bool cpu_wait_death(unsigned int cpu, int seconds)
8038dad7e88858 Paul E. McKenney 2015-02-25  426  {
8038dad7e88858 Paul E. McKenney 2015-02-25  427  	int jf_left = seconds * HZ;
8038dad7e88858 Paul E. McKenney 2015-02-25  428  	int oldstate;
8038dad7e88858 Paul E. McKenney 2015-02-25  429  	bool ret = true;
8038dad7e88858 Paul E. McKenney 2015-02-25  430  	int sleep_jf = 1;
8038dad7e88858 Paul E. McKenney 2015-02-25  431  
8038dad7e88858 Paul E. McKenney 2015-02-25  432  	might_sleep();
8038dad7e88858 Paul E. McKenney 2015-02-25  433  
8038dad7e88858 Paul E. McKenney 2015-02-25  434  	/* The outgoing CPU will normally get done quite quickly. */
8038dad7e88858 Paul E. McKenney 2015-02-25  435  	if (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) == CPU_DEAD)
8038dad7e88858 Paul E. McKenney 2015-02-25  436  		goto update_state;

Uninitialized.

8038dad7e88858 Paul E. McKenney 2015-02-25  437  	udelay(5);
8038dad7e88858 Paul E. McKenney 2015-02-25  438  
8038dad7e88858 Paul E. McKenney 2015-02-25  439  	/* But if the outgoing CPU dawdles, wait increasingly long times. */
8038dad7e88858 Paul E. McKenney 2015-02-25  440  	while (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) != CPU_DEAD) {
8038dad7e88858 Paul E. McKenney 2015-02-25  441  		schedule_timeout_uninterruptible(sleep_jf);
8038dad7e88858 Paul E. McKenney 2015-02-25  442  		jf_left -= sleep_jf;
8038dad7e88858 Paul E. McKenney 2015-02-25  443  		if (jf_left <= 0)
8038dad7e88858 Paul E. McKenney 2015-02-25  444  			break;
8038dad7e88858 Paul E. McKenney 2015-02-25  445  		sleep_jf = DIV_ROUND_UP(sleep_jf * 11, 10);
8038dad7e88858 Paul E. McKenney 2015-02-25  446  	}
8038dad7e88858 Paul E. McKenney 2015-02-25  447  	oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu));
2d1e07c7534c14 Uros Bizjak      2022-08-23  448  update_state:
8038dad7e88858 Paul E. McKenney 2015-02-25 @449  	if (oldstate == CPU_DEAD) {
                                                            ^^^^^^^^^^^^^^^^^^^^


8038dad7e88858 Paul E. McKenney 2015-02-25  450  		/* Outgoing CPU died normally, update state. */
8038dad7e88858 Paul E. McKenney 2015-02-25  451  		smp_mb(); /* atomic_read() before update. */
8038dad7e88858 Paul E. McKenney 2015-02-25  452  		atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_POST_DEAD);
8038dad7e88858 Paul E. McKenney 2015-02-25  453  	} else {
8038dad7e88858 Paul E. McKenney 2015-02-25  454  		/* Outgoing CPU still hasn't died, set state accordingly. */
2d1e07c7534c14 Uros Bizjak      2022-08-23  455  		if (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu),
2d1e07c7534c14 Uros Bizjak      2022-08-23  456  					&oldstate, CPU_BROKEN))
8038dad7e88858 Paul E. McKenney 2015-02-25  457  			goto update_state;
8038dad7e88858 Paul E. McKenney 2015-02-25  458  		ret = false;
8038dad7e88858 Paul E. McKenney 2015-02-25  459  	}
8038dad7e88858 Paul E. McKenney 2015-02-25  460  	return ret;
8038dad7e88858 Paul E. McKenney 2015-02-25  461  }

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