| 1 | |
| 2 | |
| 3 | * lib/smp_processor_id.c
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| 4 | *
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| 5 | * DEBUG_PREEMPT variant of smp_processor_id().
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| 6 |
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| 7 | #include <linux/export.h>
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| 8 | #include <linux/kprobes.h>
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| 9 | #include <linux/sched.h>
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| 10 |
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| 11 | noinstr static
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| 12 | unsigned int check_preemption_disabled(const char *what1, const char *what2)
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| 13 | {
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| 14 | int this_cpu = raw_smp_processor_id();
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| 15 |
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| 16 | if (likely(preempt_count()))
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| 17 | goto out;
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| 18 |
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| 19 | if (irqs_disabled())
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| 20 | goto out;
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| 21 |
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| 22 | if (is_percpu_thread())
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| 23 | goto out;
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| 24 |
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| 25 | if (current->migration_disabled)
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| 26 | goto out;
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| 27 |
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| 28 | |
| 29 | * It is valid to assume CPU-locality during early bootup:
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| 30 |
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| 31 | if (system_state < SYSTEM_SCHEDULING)
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| 32 | goto out;
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| 33 |
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| 34 | |
| 35 | * Avoid recursion:
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| 36 |
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| 37 | preempt_disable_notrace();
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| 38 |
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| 39 | instrumentation_begin();
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| 40 | if (!printk_ratelimit())
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| 41 | goto out_enable;
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| 42 |
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| 43 | printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
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| 44 | what1, what2, preempt_count() - 1, current->comm, current->pid);
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| 45 |
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| 46 | printk("caller is %pS\n", __builtin_return_address(0));
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| 47 | dump_stack();
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| 48 |
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| 49 | out_enable:
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| 50 | instrumentation_end();
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| 51 | preempt_enable_no_resched_notrace();
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| 52 | out:
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| 53 | return this_cpu;
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| 54 | }
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| 55 |
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| 56 | noinstr unsigned int debug_smp_processor_id(void)
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| 57 | {
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| 58 | return check_preemption_disabled("smp_processor_id", "");
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| 59 | }
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| 60 | EXPORT_SYMBOL(debug_smp_processor_id);
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| 61 |
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| 62 | noinstr void __this_cpu_preempt_check(const char *op)
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| 63 | {
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| 64 | check_preemption_disabled("__this_cpu_", op);
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| 65 | }
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| 66 | EXPORT_SYMBOL(__this_cpu_preempt_check);
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