"for (++cpu ; cpu < num_possible_cpus(); cpu++)" statement assumes possible cpus have continuous number - but that's a wrong assumption. Insted, cpumask_next() should be used.
Showing the changes to kernel/trace/trace_workqueue.c (1 of 1 file). Show all
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| @@ -91,7 +91,7 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu) · 90 unmodified lines | ||
| 91 | 91 | struct cpu_workqueue_stats *cws; |
| 92 | 92 | unsigned long flags; |
| 93 | 93 | |
| 94 | − WARN_ON(cpu < 0 || cpu >= num_possible_cpus()); | |
| 94 | + WARN_ON(cpu < 0); | |
| 95 | 95 | |
| 96 | 96 | /* Workqueues are sometimes created in atomic context */ |
| 97 | 97 | cws = kzalloc(sizeof(struct cpu_workqueue_stats), GFP_ATOMIC); |
| @@ -175,12 +175,12 @@ static void *workqueue_stat_next(void *prev, int idx) · 77 unmodified lines | ||
| 175 | 175 | spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags); |
| 176 | 176 | if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) { |
| 177 | 177 | spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags); |
| 178 | − for (++cpu ; cpu < num_possible_cpus(); cpu++) { | |
| 179 | − ret = workqueue_stat_start_cpu(cpu); | |
| 180 | − if (ret) | |
| 181 | − return ret; | |
| 182 | − } | |
| 183 | − return NULL; | |
| 178 | + do { | |
| 179 | + cpu = cpumask_next(cpu, cpu_possible_mask); | |
| 180 | + if (cpu >= nr_cpu_ids) | |
| 181 | + return NULL; | |
| 182 | + } while (!(ret = workqueue_stat_start_cpu(cpu))); | |
| 183 | + return ret; | |
| 184 | 184 | } |
| 185 | 185 | spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags); |
| 186 | 186 | |