ftrace: Add self-tests for multiple function trace users

Add some basic sanity tests for multiple users of the function
tracer at startup.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 217 insertions, 1 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5e9dfc6286dd..6b69c4bd306f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -419,6 +419,8 @@ extern void trace_find_cmdline(int pid, char comm[]);
 extern unsigned long ftrace_update_tot_cnt;
 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 extern int DYN_FTRACE_TEST_NAME(void);
+#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
+extern int DYN_FTRACE_TEST_NAME2(void);
 #endif
 
 extern int ring_buffer_expanded;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 0fa2db305b7c..288541f977fb 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -101,6 +101,206 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+static int trace_selftest_test_probe1_cnt;
+static void trace_selftest_test_probe1_func(unsigned long ip,
+                                            unsigned long pip)
+{
+        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)
+{
+        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)
+{
+        trace_selftest_test_probe3_cnt++;
+}
+
+static int trace_selftest_test_global_cnt;
+static void trace_selftest_test_global_func(unsigned long ip,
+                                            unsigned long pip)
+{
+        trace_selftest_test_global_cnt++;
+}
+
+static int trace_selftest_test_dyn_cnt;
+static void trace_selftest_test_dyn_func(unsigned long ip,
+                                         unsigned long pip)
+{
+        trace_selftest_test_dyn_cnt++;
+}
+
+static struct ftrace_ops test_probe1 = {
+        .func                   = trace_selftest_test_probe1_func,
+};
+
+static struct ftrace_ops test_probe2 = {
+        .func                   = trace_selftest_test_probe2_func,
+};
+
+static struct ftrace_ops test_probe3 = {
+        .func                   = trace_selftest_test_probe3_func,
+};
+
+static struct ftrace_ops test_global = {
+        .func                   = trace_selftest_test_global_func,
+        .flags                  = FTRACE_OPS_FL_GLOBAL,
+};
+
+static void print_counts(void)
+{
+        printk("(%d %d %d %d %d) ",
+               trace_selftest_test_probe1_cnt,
+               trace_selftest_test_probe2_cnt,
+               trace_selftest_test_probe3_cnt,
+               trace_selftest_test_global_cnt,
+               trace_selftest_test_dyn_cnt);
+}
+
+static void reset_counts(void)
+{
+        trace_selftest_test_probe1_cnt = 0;
+        trace_selftest_test_probe2_cnt = 0;
+        trace_selftest_test_probe3_cnt = 0;
+        trace_selftest_test_global_cnt = 0;
+        trace_selftest_test_dyn_cnt = 0;
+}
+
+static int trace_selftest_ops(int cnt)
+{
+        int save_ftrace_enabled = ftrace_enabled;
+        struct ftrace_ops *dyn_ops;
+        char *func1_name;
+        char *func2_name;
+        int len1;
+        int len2;
+        int ret = -1;
+
+        printk(KERN_CONT "PASSED\n");
+        pr_info("Testing dynamic ftrace ops #%d: ", cnt);
+
+        ftrace_enabled = 1;
+        reset_counts();
+
+        /* Handle PPC64 '.' name */
+        func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
+        func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);
+        len1 = strlen(func1_name);
+        len2 = strlen(func2_name);
+
+        /*
+         * Probe 1 will trace function 1.
+         * Probe 2 will trace function 2.
+         * Probe 3 will trace functions 1 and 2.
+         */
+        ftrace_set_filter(&test_probe1, func1_name, len1, 1);
+        ftrace_set_filter(&test_probe2, func2_name, len2, 1);
+        ftrace_set_filter(&test_probe3, func1_name, len1, 1);
+        ftrace_set_filter(&test_probe3, func2_name, len2, 0);
+
+        register_ftrace_function(&test_probe1);
+        register_ftrace_function(&test_probe2);
+        register_ftrace_function(&test_probe3);
+        register_ftrace_function(&test_global);
+
+        DYN_FTRACE_TEST_NAME();
+
+        print_counts();
+
+        if (trace_selftest_test_probe1_cnt != 1)
+                goto out;
+        if (trace_selftest_test_probe2_cnt != 0)
+                goto out;
+        if (trace_selftest_test_probe3_cnt != 1)
+                goto out;
+        if (trace_selftest_test_global_cnt == 0)
+                goto out;
+
+        DYN_FTRACE_TEST_NAME2();
+
+        print_counts();
+
+        if (trace_selftest_test_probe1_cnt != 1)
+                goto out;
+        if (trace_selftest_test_probe2_cnt != 1)
+                goto out;
+        if (trace_selftest_test_probe3_cnt != 2)
+                goto out;
+
+        /* Add a dynamic probe */
+        dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);
+        if (!dyn_ops) {
+                printk("MEMORY ERROR ");
+                goto out;
+        }
+
+        dyn_ops->func = trace_selftest_test_dyn_func;
+
+        register_ftrace_function(dyn_ops);
+
+        trace_selftest_test_global_cnt = 0;
+
+        DYN_FTRACE_TEST_NAME();
+
+        print_counts();
+
+        if (trace_selftest_test_probe1_cnt != 2)
+                goto out_free;
+        if (trace_selftest_test_probe2_cnt != 1)
+                goto out_free;
+        if (trace_selftest_test_probe3_cnt != 3)
+                goto out_free;
+        if (trace_selftest_test_global_cnt == 0)
+                goto out;
+        if (trace_selftest_test_dyn_cnt == 0)
+                goto out_free;
+
+        DYN_FTRACE_TEST_NAME2();
+
+        print_counts();
+
+        if (trace_selftest_test_probe1_cnt != 2)
+                goto out_free;
+        if (trace_selftest_test_probe2_cnt != 2)
+                goto out_free;
+        if (trace_selftest_test_probe3_cnt != 4)
+                goto out_free;
+
+        ret = 0;
+ out_free:
+        unregister_ftrace_function(dyn_ops);
+        kfree(dyn_ops);
+
+ out:
+        /* Purposely unregister in the same order */
+        unregister_ftrace_function(&test_probe1);
+        unregister_ftrace_function(&test_probe2);
+        unregister_ftrace_function(&test_probe3);
+        unregister_ftrace_function(&test_global);
+
+        /* Make sure everything is off */
+        reset_counts();
+        DYN_FTRACE_TEST_NAME();
+        DYN_FTRACE_TEST_NAME();
+
+        if (trace_selftest_test_probe1_cnt ||
+            trace_selftest_test_probe2_cnt ||
+            trace_selftest_test_probe3_cnt ||
+            trace_selftest_test_global_cnt ||
+            trace_selftest_test_dyn_cnt)
+                ret = -1;
+
+        ftrace_enabled = save_ftrace_enabled;
+
+        return ret;
+}
+
 /* Test dynamic code modification and ftrace filters */
 int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
                                            struct trace_array *tr,
@@ -166,16 +366,20 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 
         /* 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) {
+                trace->reset(tr);
                 printk(KERN_CONT ".. filter failed count=%ld ..", count);
                 ret = -1;
                 goto out;
         }
 
+        /* Test the ops with global tracing running */
+        ret = trace_selftest_ops(1);
+        trace->reset(tr);
+
  out:
         ftrace_enabled = save_ftrace_enabled;
         tracer_enabled = save_tracer_enabled;
@@ -183,6 +387,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
         /* Enable tracing on all functions again */
         ftrace_set_global_filter(NULL, 0, 1);
 
+        /* Test the ops with global tracing off */
+        if (!ret)
+                ret = trace_selftest_ops(2);
+
         return ret;
 }
 #else
diff --git a/kernel/trace/trace_selftest_dynamic.c b/kernel/trace/trace_selftest_dynamic.c
index 54dd77cce5bf..b4c475a0a48b 100644
--- a/kernel/trace/trace_selftest_dynamic.c
+++ b/kernel/trace/trace_selftest_dynamic.c
@@ -5,3 +5,9 @@ int DYN_FTRACE_TEST_NAME(void)
         /* used to call mcount */
         return 0;
 }
+
+int DYN_FTRACE_TEST_NAME2(void)
+{
+        /* used to call mcount */
+        return 0;
+}