/* Include in trace.c */
+#include <linux/stringify.h>
#include <linux/kthread.h>
#include <linux/delay.h>
+#include <linux/slab.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_PRINT:
+ case TRACE_SPECIAL:
+ case TRACE_BRANCH:
+ case TRACE_GRAPH_ENT:
+ case TRACE_GRAPH_RET:
+ case TRACE_KSYM:
return 1;
}
return 0;
}
-static int
-trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data)
+static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
- struct trace_entry *entries;
- struct page *page;
- int idx = 0;
- int i;
+ struct ring_buffer_event *event;
+ struct trace_entry *entry;
+ unsigned int loops = 0;
- BUG_ON(list_empty(&data->trace_pages));
- page = list_entry(data->trace_pages.next, struct page, lru);
- entries = page_address(page);
+ while ((event = ring_buffer_consume(tr->buffer, cpu, NULL, NULL))) {
+ entry = ring_buffer_event_data(event);
- 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);
+ /*
+ * The ring buffer is a size of trace_buf_size, if
+ * we loop more than the size, there's something wrong
+ * with the ring buffer.
+ */
+ if (loops++ > trace_buf_size) {
+ printk(KERN_CONT ".. bad ring buffer ");
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;
+ if (!trace_valid_entry(entry)) {
+ printk(KERN_CONT ".. invalid entry %d ",
+ entry->type);
+ goto failed;
}
}
-
- page = virt_to_page(entries);
- if (page->lru.next != &data->trace_pages) {
- printk(KERN_CONT ".. too many entries");
- goto failed;
- }
-
return 0;
failed:
*/
static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
{
- unsigned long cnt = 0;
- int cpu;
- int ret = 0;
+ unsigned long flags, cnt = 0;
+ int cpu, ret = 0;
- for_each_possible_cpu(cpu) {
- if (!head_page(tr->data[cpu]))
- continue;
+ /* Don't allow flipping of max traces now */
+ local_irq_save(flags);
+ arch_spin_lock(&ftrace_max_lock);
- cnt += tr->data[cpu]->trace_idx;
+ cnt = ring_buffer_entries(tr->buffer);
- ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
+ /*
+ * The trace_test_buffer_cpu runs a while loop to consume all data.
+ * If the calling tracer is broken, and is constantly filling
+ * the buffer, this will run forever, and hard lock the box.
+ * We disable the ring buffer while we do this test to prevent
+ * a hard lock up.
+ */
+ tracing_off();
+ for_each_possible_cpu(cpu) {
+ ret = trace_test_buffer_cpu(tr, cpu);
if (ret)
break;
}
+ tracing_on();
+ arch_spin_unlock(&ftrace_max_lock);
+ local_irq_restore(flags);
if (count)
*count = cnt;
return ret;
}
-#ifdef CONFIG_FTRACE
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-
-#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
-#define __STR(x) #x
-#define STR(x) __STR(x)
-static int DYN_FTRACE_TEST_NAME(void)
+static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
{
- /* used to call mcount */
- return 0;
+ printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
+ trace->name, init_ret);
}
+#ifdef CONFIG_FUNCTION_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
/* 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;
+ unsigned long count;
+ char *func_name;
+ int ret;
/* The ftrace test PASSED */
printk(KERN_CONT "PASSED\n");
/* 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 characters to the
+ * start of the function names. We simply put a '*' to
+ * accommodate them.
+ */
+ func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
/* filter only on our function */
- ftrace_set_filter(STR(DYN_FTRACE_TEST_NAME),
- sizeof(STR(DYN_FTRACE_TEST_NAME)), 1);
+ ftrace_set_filter(func_name, strlen(func_name), 1);
/* enable tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ goto out;
+ }
+
/* Sleep for a 1/10 of a second */
msleep(100);
msleep(100);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
ftrace_enabled = 0;
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
+ tracing_start();
/* we should only have one item */
if (!ret && count != 1) {
- printk(KERN_CONT ".. filter failed ..");
+ printk(KERN_CONT ".. filter failed count=%ld ..", count);
ret = -1;
goto out;
}
+
out:
ftrace_enabled = save_ftrace_enabled;
tracer_enabled = save_tracer_enabled;
#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
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;
+ unsigned long count;
+ int ret;
/* 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);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ goto out;
+ }
+
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
ftrace_enabled = 0;
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
+ tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
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 */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+/* Maximum number of functions to trace before diagnosing a hang */
+#define GRAPH_MAX_FUNC_TEST 100000000
+
+static void
+__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode);
+static unsigned int graph_hang_thresh;
+
+/* Wrap the real function entry probe to avoid possible hanging */
+static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
+{
+ /* This is harmlessly racy, we want to approximately detect a hang */
+ if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
+ ftrace_graph_stop();
+ printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
+ if (ftrace_dump_on_oops)
+ __ftrace_dump(false, DUMP_ALL);
+ return 0;
+ }
+
+ return trace_graph_entry(trace);
+}
+
+/*
+ * Pretty much the same than for the function tracer from which the selftest
+ * has been borrowed.
+ */
+int
+trace_selftest_startup_function_graph(struct tracer *trace,
+ struct trace_array *tr)
+{
+ int ret;
+ unsigned long count;
+
+ /*
+ * Simulate the init() callback but we attach a watchdog callback
+ * to detect and recover from possible hangs
+ */
+ tracing_reset_online_cpus(tr);
+ set_graph_array(tr);
+ ret = register_ftrace_graph(&trace_graph_return,
+ &trace_graph_entry_watchdog);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ goto out;
+ }
+ tracing_start_cmdline_record();
+
+ /* Sleep for a 1/10 of a second */
+ msleep(100);
+
+ /* Have we just recovered from a hang? */
+ if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
+ tracing_selftest_disabled = true;
+ ret = -1;
+ goto out;
+ }
+
+ tracing_stop();
+
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+
+ trace->reset(tr);
+ tracing_start();
+
+ if (!ret && !count) {
+ printk(KERN_CONT ".. no entries found ..");
+ ret = -1;
+ goto out;
+ }
+
+ /* Don't test dynamic tracing, the function tracer already did */
+
+out:
+ /* Stop it if we failed */
+ if (ret)
+ ftrace_graph_stop();
+
+ return ret;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
#ifdef CONFIG_IRQSOFF_TRACER
int
int ret;
/* start the tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
/* reset the max latency */
tracing_max_latency = 0;
/* disable interrupts for a bit */
local_irq_disable();
udelay(100);
local_irq_enable();
+
+ /*
+ * Stop the tracer to avoid a warning subsequent
+ * to buffer flipping failure because tracing_stop()
+ * disables the tr and max buffers, making flipping impossible
+ * in case of parallels max irqs off latencies.
+ */
+ trace->stop(tr);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
ret = trace_test_buffer(&max_tr, &count);
trace->reset(tr);
+ tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
unsigned long count;
int ret;
+ /*
+ * Now that the big kernel lock is no longer preemptable,
+ * and this is called with the BKL held, it will always
+ * fail. If preemption is already disabled, simply
+ * pass the test. When the BKL is removed, or becomes
+ * preemptible again, we will once again test this,
+ * so keep it in.
+ */
+ if (preempt_count()) {
+ printk(KERN_CONT "can not test ... force ");
+ return 0;
+ }
+
/* start the tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
/* reset the max latency */
tracing_max_latency = 0;
/* disable preemption for a bit */
preempt_disable();
udelay(100);
preempt_enable();
+
+ /*
+ * Stop the tracer to avoid a warning subsequent
+ * to buffer flipping failure because tracing_stop()
+ * disables the tr and max buffers, making flipping impossible
+ * in case of parallels max preempt off latencies.
+ */
+ trace->stop(tr);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
ret = trace_test_buffer(&max_tr, &count);
trace->reset(tr);
+ tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
unsigned long count;
int ret;
+ /*
+ * Now that the big kernel lock is no longer preemptable,
+ * and this is called with the BKL held, it will always
+ * fail. If preemption is already disabled, simply
+ * pass the test. When the BKL is removed, or becomes
+ * preemptible again, we will once again test this,
+ * so keep it in.
+ */
+ if (preempt_count()) {
+ printk(KERN_CONT "can not test ... force ");
+ return 0;
+ }
+
/* start the tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ goto out_no_start;
+ }
/* reset the max latency */
tracing_max_latency = 0;
/* reverse the order of preempt vs irqs */
local_irq_enable();
+ /*
+ * Stop the tracer to avoid a warning subsequent
+ * to buffer flipping failure because tracing_stop()
+ * disables the tr and max buffers, making flipping impossible
+ * in case of parallels max irqs/preempt off latencies.
+ */
+ trace->stop(tr);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (ret)
/* do the test by disabling interrupts first this time */
tracing_max_latency = 0;
- tr->ctrl = 1;
- trace->ctrl_update(tr);
+ tracing_start();
+ trace->start(tr);
+
preempt_disable();
local_irq_disable();
udelay(100);
/* reverse the order of preempt vs irqs */
local_irq_enable();
+ trace->stop(tr);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (ret)
goto out;
}
- out:
+out:
+ tracing_start();
+out_no_start:
trace->reset(tr);
tracing_max_latency = save_max;
}
#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
+#ifdef CONFIG_NOP_TRACER
+int
+trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
+{
+ /* What could possibly go wrong? */
+ return 0;
+}
+#endif
+
#ifdef CONFIG_SCHED_TRACER
static int trace_wakeup_test_thread(void *data)
{
- struct completion *x = data;
-
/* Make this a RT thread, doesn't need to be too high */
+ struct sched_param param = { .sched_priority = 5 };
+ struct completion *x = data;
- rt_mutex_setprio(current, MAX_RT_PRIO - 5);
+ sched_setscheduler(current, SCHED_FIFO, ¶m);
/* Make it know we have a new prio */
complete(x);
wait_for_completion(&isrt);
/* start the tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
/* reset the max latency */
tracing_max_latency = 0;
wake_up_process(p);
+ /* give a little time to let the thread wake up */
+ msleep(100);
+
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
trace->reset(tr);
+ tracing_start();
tracing_max_latency = save_max;
int ret;
/* start the tracing */
- tr->ctrl = 1;
- trace->init(tr);
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
- tr->ctrl = 0;
- trace->ctrl_update(tr);
+ tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
+ tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
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 */
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
+ /* Sleep for a 1/10 of a second */
+ msleep(100);
+ /* stop the tracing. */
+ tracing_stop();
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+ trace->reset(tr);
+ tracing_start();
+
+ if (!ret && !count) {
+ printk(KERN_CONT ".. no entries found ..");
+ ret = -1;
+ }
+
+ return ret;
+}
+#endif /* CONFIG_SYSPROF_TRACER */
+
+#ifdef CONFIG_BRANCH_TRACER
+int
+trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
+{
+ unsigned long count;
+ int ret;
+
+ /* start the tracing */
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
+ /* Sleep for a 1/10 of a second */
+ msleep(100);
+ /* stop the tracing. */
+ tracing_stop();
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+ trace->reset(tr);
+ tracing_start();
+
+ if (!ret && !count) {
+ printk(KERN_CONT ".. no entries found ..");
+ ret = -1;
+ }
+
+ return ret;
+}
+#endif /* CONFIG_BRANCH_TRACER */
+
+#ifdef CONFIG_KSYM_TRACER
+static int ksym_selftest_dummy;
+
+int
+trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr)
+{
+ unsigned long count;
+ int ret;
+
+ /* start the tracing */
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
+ ksym_selftest_dummy = 0;
+ /* Register the read-write tracing request */
+
+ ret = process_new_ksym_entry("ksym_selftest_dummy",
+ HW_BREAKPOINT_R | HW_BREAKPOINT_W,
+ (unsigned long)(&ksym_selftest_dummy));
+
+ if (ret < 0) {
+ printk(KERN_CONT "ksym_trace read-write startup test failed\n");
+ goto ret_path;
+ }
+ /* Perform a read and a write operation over the dummy variable to
+ * trigger the tracer
+ */
+ if (ksym_selftest_dummy == 0)
+ ksym_selftest_dummy++;
+
+ /* stop the tracing. */
+ tracing_stop();
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+ trace->reset(tr);
+ tracing_start();
+
+ /* read & write operations - one each is performed on the dummy variable
+ * triggering two entries in the trace buffer
+ */
+ if (!ret && count != 2) {
+ printk(KERN_CONT "Ksym tracer startup test failed");
+ ret = -1;
+ }
+
+ret_path:
+ return ret;
+}
+#endif /* CONFIG_KSYM_TRACER */
+
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