1 files changed, 563 insertions, 0 deletions

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
new file mode 100644
index 000000000000..0911b7e073bf
--- /dev/null
+++ b/kernel/trace/trace_selftest.c
@@ -0,0 +1,563 @@
+/* Include in trace.c */
+
+#include <linux/kthread.h>
+#include <linux/delay.h>
+
+static inline int trace_valid_entry(struct trace_entry *entry)
+{
+        switch (entry->type) {
+        case TRACE_FN:
+        case TRACE_CTX:
+        case TRACE_WAKE:
+        case TRACE_STACK:
+        case TRACE_SPECIAL:
+                return 1;
+        }
+        return 0;
+}
+
+static int
+trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data)
+{
+        struct trace_entry *entries;
+        struct page *page;
+        int idx = 0;
+        int i;
+
+        BUG_ON(list_empty(&data->trace_pages));
+        page = list_entry(data->trace_pages.next, struct page, lru);
+        entries = page_address(page);
+
+        check_pages(data);
+        if (head_page(data) != entries)
+                goto failed;
+
+        /*
+         * The starting trace buffer always has valid elements,
+         * if any element exists.
+         */
+        entries = head_page(data);
+
+        for (i = 0; i < tr->entries; i++) {
+
+                if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) {
+                        printk(KERN_CONT ".. invalid entry %d ",
+                                entries[idx].type);
+                        goto failed;
+                }
+
+                idx++;
+                if (idx >= ENTRIES_PER_PAGE) {
+                        page = virt_to_page(entries);
+                        if (page->lru.next == &data->trace_pages) {
+                                if (i != tr->entries - 1) {
+                                        printk(KERN_CONT ".. entries buffer mismatch");
+                                        goto failed;
+                                }
+                        } else {
+                                page = list_entry(page->lru.next, struct page, lru);
+                                entries = page_address(page);
+                        }
+                        idx = 0;
+                }
+        }
+
+        page = virt_to_page(entries);
+        if (page->lru.next != &data->trace_pages) {
+                printk(KERN_CONT ".. too many entries");
+                goto failed;
+        }
+
+        return 0;
+
+ failed:
+        /* disable tracing */
+        tracing_disabled = 1;
+        printk(KERN_CONT ".. corrupted trace buffer .. ");
+        return -1;
+}
+
+/*
+ * Test the trace buffer to see if all the elements
+ * are still sane.
+ */
+static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
+{
+        unsigned long flags, cnt = 0;
+        int cpu, ret = 0;
+
+        /* Don't allow flipping of max traces now */
+        raw_local_irq_save(flags);
+        __raw_spin_lock(&ftrace_max_lock);
+        for_each_possible_cpu(cpu) {
+                if (!head_page(tr->data[cpu]))
+                        continue;
+
+                cnt += tr->data[cpu]->trace_idx;
+
+                ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
+                if (ret)
+                        break;
+        }
+        __raw_spin_unlock(&ftrace_max_lock);
+        raw_local_irq_restore(flags);
+
+        if (count)
+                *count = cnt;
+
+        return ret;
+}
+
+#ifdef CONFIG_FTRACE
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+#define __STR(x) #x
+#define STR(x) __STR(x)
+
+/* Test dynamic code modification and ftrace filters */
+int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
+                                           struct trace_array *tr,
+                                           int (*func)(void))
+{
+        unsigned long count;
+        int ret;
+        int save_ftrace_enabled = ftrace_enabled;
+        int save_tracer_enabled = tracer_enabled;
+        char *func_name;
+
+        /* The ftrace test PASSED */
+        printk(KERN_CONT "PASSED\n");
+        pr_info("Testing dynamic ftrace: ");
+
+        /* enable tracing, and record the filter function */
+        ftrace_enabled = 1;
+        tracer_enabled = 1;
+
+        /* passed in by parameter to fool gcc from optimizing */
+        func();
+
+        /* update the records */
+        ret = ftrace_force_update();
+        if (ret) {
+                printk(KERN_CONT ".. ftraced failed .. ");
+                return ret;
+        }
+
+        /*
+         * Some archs *cough*PowerPC*cough* add charachters to the
+         * start of the function names. We simply put a '*' to
+         * accomodate them.
+         */
+        func_name = "*" STR(DYN_FTRACE_TEST_NAME);
+
+        /* filter only on our function */
+        ftrace_set_filter(func_name, strlen(func_name), 1);
+
+        /* enable tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* Sleep for a 1/10 of a second */
+        msleep(100);
+
+        /* we should have nothing in the buffer */
+        ret = trace_test_buffer(tr, &count);
+        if (ret)
+                goto out;
+
+        if (count) {
+                ret = -1;
+                printk(KERN_CONT ".. filter did not filter .. ");
+                goto out;
+        }
+
+        /* call our function again */
+        func();
+
+        /* sleep again */
+        msleep(100);
+
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        ftrace_enabled = 0;
+
+        /* check the trace buffer */
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+
+        /* we should only have one item */
+        if (!ret && count != 1) {
+                printk(KERN_CONT ".. filter failed count=%ld ..", count);
+                ret = -1;
+                goto out;
+        }
+ out:
+        ftrace_enabled = save_ftrace_enabled;
+        tracer_enabled = save_tracer_enabled;
+
+        /* Enable tracing on all functions again */
+        ftrace_set_filter(NULL, 0, 1);
+
+        return ret;
+}
+#else
+# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
+#endif /* CONFIG_DYNAMIC_FTRACE */
+/*
+ * Simple verification test of ftrace function tracer.
+ * Enable ftrace, sleep 1/10 second, and then read the trace
+ * buffer to see if all is in order.
+ */
+int
+trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long count;
+        int ret;
+        int save_ftrace_enabled = ftrace_enabled;
+        int save_tracer_enabled = tracer_enabled;
+
+        /* make sure msleep has been recorded */
+        msleep(1);
+
+        /* force the recorded functions to be traced */
+        ret = ftrace_force_update();
+        if (ret) {
+                printk(KERN_CONT ".. ftraced failed .. ");
+                return ret;
+        }
+
+        /* start the tracing */
+        ftrace_enabled = 1;
+        tracer_enabled = 1;
+
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* Sleep for a 1/10 of a second */
+        msleep(100);
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        ftrace_enabled = 0;
+
+        /* check the trace buffer */
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+                goto out;
+        }
+
+        ret = trace_selftest_startup_dynamic_tracing(trace, tr,
+                                                     DYN_FTRACE_TEST_NAME);
+
+ out:
+        ftrace_enabled = save_ftrace_enabled;
+        tracer_enabled = save_tracer_enabled;
+
+        /* kill ftrace totally if we failed */
+        if (ret)
+                ftrace_kill();
+
+        return ret;
+}
+#endif /* CONFIG_FTRACE */
+
+#ifdef CONFIG_IRQSOFF_TRACER
+int
+trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long save_max = tracing_max_latency;
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* reset the max latency */
+        tracing_max_latency = 0;
+        /* disable interrupts for a bit */
+        local_irq_disable();
+        udelay(100);
+        local_irq_enable();
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check both trace buffers */
+        ret = trace_test_buffer(tr, NULL);
+        if (!ret)
+                ret = trace_test_buffer(&max_tr, &count);
+        trace->reset(tr);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+        }
+
+        tracing_max_latency = save_max;
+
+        return ret;
+}
+#endif /* CONFIG_IRQSOFF_TRACER */
+
+#ifdef CONFIG_PREEMPT_TRACER
+int
+trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long save_max = tracing_max_latency;
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* reset the max latency */
+        tracing_max_latency = 0;
+        /* disable preemption for a bit */
+        preempt_disable();
+        udelay(100);
+        preempt_enable();
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check both trace buffers */
+        ret = trace_test_buffer(tr, NULL);
+        if (!ret)
+                ret = trace_test_buffer(&max_tr, &count);
+        trace->reset(tr);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+        }
+
+        tracing_max_latency = save_max;
+
+        return ret;
+}
+#endif /* CONFIG_PREEMPT_TRACER */
+
+#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
+int
+trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long save_max = tracing_max_latency;
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+
+        /* reset the max latency */
+        tracing_max_latency = 0;
+
+        /* disable preemption and interrupts for a bit */
+        preempt_disable();
+        local_irq_disable();
+        udelay(100);
+        preempt_enable();
+        /* reverse the order of preempt vs irqs */
+        local_irq_enable();
+
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check both trace buffers */
+        ret = trace_test_buffer(tr, NULL);
+        if (ret)
+                goto out;
+
+        ret = trace_test_buffer(&max_tr, &count);
+        if (ret)
+                goto out;
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+                goto out;
+        }
+
+        /* do the test by disabling interrupts first this time */
+        tracing_max_latency = 0;
+        tr->ctrl = 1;
+        trace->ctrl_update(tr);
+        preempt_disable();
+        local_irq_disable();
+        udelay(100);
+        preempt_enable();
+        /* reverse the order of preempt vs irqs */
+        local_irq_enable();
+
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check both trace buffers */
+        ret = trace_test_buffer(tr, NULL);
+        if (ret)
+                goto out;
+
+        ret = trace_test_buffer(&max_tr, &count);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+                goto out;
+        }
+
+ out:
+        trace->reset(tr);
+        tracing_max_latency = save_max;
+
+        return ret;
+}
+#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
+
+#ifdef CONFIG_SCHED_TRACER
+static int trace_wakeup_test_thread(void *data)
+{
+        /* Make this a RT thread, doesn't need to be too high */
+        struct sched_param param = { .sched_priority = 5 };
+        struct completion *x = data;
+
+        sched_setscheduler(current, SCHED_FIFO, &param);
+
+        /* Make it know we have a new prio */
+        complete(x);
+
+        /* now go to sleep and let the test wake us up */
+        set_current_state(TASK_INTERRUPTIBLE);
+        schedule();
+
+        /* we are awake, now wait to disappear */
+        while (!kthread_should_stop()) {
+                /*
+                 * This is an RT task, do short sleeps to let
+                 * others run.
+                 */
+                msleep(100);
+        }
+
+        return 0;
+}
+
+int
+trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long save_max = tracing_max_latency;
+        struct task_struct *p;
+        struct completion isrt;
+        unsigned long count;
+        int ret;
+
+        init_completion(&isrt);
+
+        /* create a high prio thread */
+        p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
+        if (IS_ERR(p)) {
+                printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
+                return -1;
+        }
+
+        /* make sure the thread is running at an RT prio */
+        wait_for_completion(&isrt);
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* reset the max latency */
+        tracing_max_latency = 0;
+
+        /* sleep to let the RT thread sleep too */
+        msleep(100);
+
+        /*
+         * Yes this is slightly racy. It is possible that for some
+         * strange reason that the RT thread we created, did not
+         * call schedule for 100ms after doing the completion,
+         * and we do a wakeup on a task that already is awake.
+         * But that is extremely unlikely, and the worst thing that
+         * happens in such a case, is that we disable tracing.
+         * Honestly, if this race does happen something is horrible
+         * wrong with the system.
+         */
+
+        wake_up_process(p);
+
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check both trace buffers */
+        ret = trace_test_buffer(tr, NULL);
+        if (!ret)
+                ret = trace_test_buffer(&max_tr, &count);
+
+
+        trace->reset(tr);
+
+        tracing_max_latency = save_max;
+
+        /* kill the thread */
+        kthread_stop(p);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+        }
+
+        return ret;
+}
+#endif /* CONFIG_SCHED_TRACER */
+
+#ifdef CONFIG_CONTEXT_SWITCH_TRACER
+int
+trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* Sleep for a 1/10 of a second */
+        msleep(100);
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check the trace buffer */
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+
+        if (!ret && !count) {
+                printk(KERN_CONT ".. no entries found ..");
+                ret = -1;
+        }
+
+        return ret;
+}
+#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
+
+#ifdef CONFIG_SYSPROF_TRACER
+int
+trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        tr->ctrl = 1;
+        trace->init(tr);
+        /* Sleep for a 1/10 of a second */
+        msleep(100);
+        /* stop the tracing. */
+        tr->ctrl = 0;
+        trace->ctrl_update(tr);
+        /* check the trace buffer */
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+
+        return ret;
+}
+#endif /* CONFIG_SYSPROF_TRACER */