[tj-wq:for-7.3 11/19] kernel/workqueue.c:5682:57: sparse: sparse: incorrect type in initializer (different address spaces)

Hi Breno,

FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-7.3
head:   a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656
commit: 79f23600bc7b13a35fd148131245c283d14604a8 [11/19] workqueue: factor out get_percpu_pool()
config: alpha-randconfig-r123-20260812 (https://download.01.org/0day-ci/archive/20260812/[email protected]/config)
compiler: alpha-linux-gcc (GCC) 9.5.0
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260812/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

sparse warnings: (new ones prefixed by >>)
   kernel/workqueue.c:5676:21: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct pool_workqueue [noderef] __rcu *[noderef] __percpu *cpu_pwq @@     got struct pool_workqueue *[noderef] __percpu * @@
   kernel/workqueue.c:5676:21: sparse:     expected struct pool_workqueue [noderef] __rcu *[noderef] __percpu *cpu_pwq
   kernel/workqueue.c:5676:21: sparse:     got struct pool_workqueue *[noderef] __percpu *
>> kernel/workqueue.c:5682:57: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected struct pool_workqueue **pwq_p @@     got struct pool_workqueue [noderef] __rcu ** @@
   kernel/workqueue.c:5682:57: sparse:     expected struct pool_workqueue **pwq_p
   kernel/workqueue.c:5682:57: sparse:     got struct pool_workqueue [noderef] __rcu **
   kernel/workqueue.c:5719:54: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected struct pool_workqueue *pwq @@     got struct pool_workqueue [noderef] __rcu * @@
   kernel/workqueue.c:5719:54: sparse:     expected struct pool_workqueue *pwq
   kernel/workqueue.c:5719:54: sparse:     got struct pool_workqueue [noderef] __rcu *
   kernel/workqueue.c:6304:13: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct pool_workqueue *pwq @@     got struct pool_workqueue [noderef] __rcu * @@
   kernel/workqueue.c:6304:13: sparse:     expected struct pool_workqueue *pwq
   kernel/workqueue.c:6304:13: sparse:     got struct pool_workqueue [noderef] __rcu *

vim +5682 kernel/workqueue.c

  5668	
  5669	static int alloc_and_link_pwqs(struct workqueue_struct *wq)
  5670	{
  5671		bool highpri = wq->flags & WQ_HIGHPRI;
  5672		int cpu, ret;
  5673	
  5674		lockdep_assert_held(&wq_pool_mutex);
  5675	
  5676		wq->cpu_pwq = alloc_percpu(struct pool_workqueue *);
  5677		if (!wq->cpu_pwq)
  5678			goto enomem;
  5679	
  5680		if (!(wq->flags & WQ_UNBOUND)) {
  5681			for_each_possible_cpu(cpu) {
> 5682				struct pool_workqueue **pwq_p = per_cpu_ptr(wq->cpu_pwq, cpu);
  5683				struct worker_pool *pool = get_percpu_pool(wq, cpu);
  5684	
  5685				*pwq_p = kmem_cache_alloc_node(pwq_cache, GFP_KERNEL,
  5686							       pool->node);
  5687				if (!*pwq_p)
  5688					goto enomem;
  5689	
  5690				init_pwq(*pwq_p, wq, pool);
  5691	
  5692				mutex_lock(&wq->mutex);
  5693				link_pwq(*pwq_p);
  5694				mutex_unlock(&wq->mutex);
  5695			}
  5696			return 0;
  5697		}
  5698	
  5699		if (wq->flags & __WQ_ORDERED) {
  5700			struct pool_workqueue *dfl_pwq;
  5701	
  5702			ret = apply_workqueue_attrs_locked(wq, ordered_wq_attrs[highpri]);
  5703			/* there should only be single pwq for ordering guarantee */
  5704			dfl_pwq = rcu_access_pointer(wq->dfl_pwq);
  5705			WARN(!ret && (wq->pwqs.next != &dfl_pwq->pwqs_node ||
  5706				      wq->pwqs.prev != &dfl_pwq->pwqs_node),
  5707			     "ordering guarantee broken for workqueue %s\n", wq->name);
  5708		} else {
  5709			ret = apply_workqueue_attrs_locked(wq, unbound_std_wq_attrs[highpri]);
  5710		}
  5711	
  5712		if (ret)
  5713			goto enomem;
  5714		return 0;
  5715	
  5716	enomem:
  5717		if (wq->cpu_pwq) {
  5718			for_each_possible_cpu(cpu) {
  5719				struct pool_workqueue *pwq = *per_cpu_ptr(wq->cpu_pwq, cpu);
  5720	
  5721				if (pwq) {
  5722					/*
  5723					 * Unlink pwq from wq->pwqs since link_pwq()
  5724					 * may have already added it. wq->mutex is not
  5725					 * needed as the wq has not been published yet.
  5726					 */
  5727					if (!list_empty(&pwq->pwqs_node))
  5728						list_del_rcu(&pwq->pwqs_node);
  5729					kmem_cache_free(pwq_cache, pwq);
  5730				}
  5731			}
  5732			free_percpu(wq->cpu_pwq);
  5733			wq->cpu_pwq = NULL;
  5734		}
  5735		return -ENOMEM;
  5736	}
  5737	

--
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