kmemleak: Select DEBUG_FS unconditionally in DEBUG_KMEMLEAK
[linux-2.6.git] / lib / smp_processor_id.c
1 /*
2  * lib/smp_processor_id.c
3  *
4  * DEBUG_PREEMPT variant of smp_processor_id().
5  */
6 #include <linux/module.h>
7 #include <linux/kallsyms.h>
8 #include <linux/sched.h>
9
10 notrace unsigned int debug_smp_processor_id(void)
11 {
12         unsigned long preempt_count = preempt_count();
13         int this_cpu = raw_smp_processor_id();
14
15         if (likely(preempt_count))
16                 goto out;
17
18         if (irqs_disabled())
19                 goto out;
20
21         /*
22          * Kernel threads bound to a single CPU can safely use
23          * smp_processor_id():
24          */
25         if (cpumask_equal(&current->cpus_allowed, cpumask_of(this_cpu)))
26                 goto out;
27
28         /*
29          * It is valid to assume CPU-locality during early bootup:
30          */
31         if (system_state != SYSTEM_RUNNING)
32                 goto out;
33
34         /*
35          * Avoid recursion:
36          */
37         preempt_disable_notrace();
38
39         if (!printk_ratelimit())
40                 goto out_enable;
41
42         printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
43                         "code: %s/%d\n",
44                         preempt_count() - 1, current->comm, current->pid);
45         print_symbol("caller is %s\n", (long)__builtin_return_address(0));
46         dump_stack();
47
48 out_enable:
49         preempt_enable_no_resched_notrace();
50 out:
51         return this_cpu;
52 }
53
54 EXPORT_SYMBOL(debug_smp_processor_id);
55