case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
+ case TRACE_HW_BRANCHES:
+ case TRACE_KSYM:
return 1;
}
return 0;
#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
#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);
+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);
+ return 0;
+ }
+
+ return trace_graph_entry(trace);
+}
+
/*
* Pretty much the same than for the function tracer from which the selftest
* has been borrowed.
int ret;
unsigned long count;
- ret = tracer_init(trace, tr);
+ /*
+ * 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 */
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. */
tracing_stop();
/* check both trace buffers */
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. */
tracing_stop();
/* check both trace buffers */
/* 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. */
tracing_stop();
/* check both trace buffers */
/* do the test by disabling interrupts first this time */
tracing_max_latency = 0;
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. */
tracing_stop();
/* check both trace buffers */
return ret;
}
#endif /* CONFIG_BRANCH_TRACER */
+
+#ifdef CONFIG_HW_BRANCH_TRACER
+int
+trace_selftest_startup_hw_branches(struct tracer *trace,
+ struct trace_array *tr)
+{
+ struct trace_iterator *iter;
+ struct tracer tracer;
+ unsigned long count;
+ int ret;
+
+ if (!trace->open) {
+ printk(KERN_CONT "missing open function...");
+ return -1;
+ }
+
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
+ /*
+ * The hw-branch tracer needs to collect the trace from the various
+ * cpu trace buffers - before tracing is stopped.
+ */
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ memcpy(&tracer, trace, sizeof(tracer));
+
+ iter->trace = &tracer;
+ iter->tr = tr;
+ iter->pos = -1;
+ mutex_init(&iter->mutex);
+
+ trace->open(iter);
+
+ mutex_destroy(&iter->mutex);
+ kfree(iter);
+
+ tracing_stop();
+
+ 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_HW_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 */
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff