path: root/kernel/trace/trace_selftest.c

/* 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_BRANCH:
	case TRACE_GRAPH_ENT:
	case TRACE_GRAPH_RET:
		return 1;
	}
	return 0;
}

static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
	struct ring_buffer_event *event;
	struct trace_entry *entry;
	unsigned int loops = 0;

	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL, NULL))) {
		entry = ring_buffer_event_data(event);

		/*
		 * 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;
		}
		if (!trace_valid_entry(entry)) {
			printk(KERN_CONT ".. invalid entry %d ",
				entry->type);
			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 */
	local_irq_save(flags);
	arch_spin_lock(&ftrace_max_lock);

	cnt = ring_buffer_entries(tr->buffer);

	/*
	 * 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;
}

static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
{
	printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
		trace->name, init_ret);
}
#ifdef CONFIG_FUNCTION_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE

static int trace_selftest_test_probe1_cnt;
static void trace_selftest_test_probe1_func(unsigned long ip,
					    unsigned long pip,
					    struct ftrace_ops *op,
					    struct pt_regs *pt_regs)
{
	trace_selftest_test_probe1_cnt++;
}

static int trace_selftest_test_probe2_cnt;
static void trace_selftest_test_probe2_func(unsigned long ip,
					    unsigned long pip,
					    struct ftrace_ops *op,
					    struct pt_regs *pt_regs)
{
	trace_selftest_test_probe2_cnt++;
}

static int trace_selftest_test_probe3_cnt;
static void trace_selftest_test_probe3_func(unsigned long ip,
					    unsigned long pip,
					    struct ftrace_ops *op,
					    struct pt_regs *