tracing/filter: Add startup tests for events filter

Adding automated tests running as late_initcall. Tests are
compiled in with CONFIG_FTRACE_STARTUP_TEST option.

Adding test event "ftrace_test_filter" used to simulate
filter processing during event occurance.

String filters are compiled and tested against several
test events with different values.

Also testing that evaluation of explicit predicates is ommited
due to the lazy filter evaluation.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1313072754-4620-11-git-send-email-jolsa@redhat.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 209 insertions, 0 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 319c3cac7d95..6a642e278241 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1329,6 +1329,9 @@ static struct filter_pred *create_pred(struct filter_parse_state *ps,
 	strcpy(pred.regex.pattern, operand2);
 	pred.regex.len = strlen(pred.regex.pattern);
 
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+	pred.field = field;
+#endif
 	return init_pred(ps, field, &pred) ? NULL : &pred;
 }
 
@@ -1926,3 +1929,209 @@ out_unlock:
 
 #endif /* CONFIG_PERF_EVENTS */
 
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace_events_filter_test.h"
+
+static int test_get_filter(char *filter_str, struct ftrace_event_call *call,
+			   struct event_filter **pfilter)
+{
+	struct event_filter *filter;
+	struct filter_parse_state *ps;
+	int err = -ENOMEM;
+
+	filter = __alloc_filter();
+	if (!filter)
+		goto out;
+
+	ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		goto free_filter;
+
+	parse_init(ps, filter_ops, filter_str);
+	err = filter_parse(ps);
+	if (err)
+		goto free_ps;
+
+	err = replace_preds(call, filter, ps, filter_str, false);
+	if (!err)
+		*pfilter = filter;
+
+ free_ps:
+	filter_opstack_clear(ps);
+	postfix_clear(ps);
+	kfree(ps);
+
+ free_filter:
+	if (err)
+		__free_filter(filter);
+
+ out:
+	return err;
+}
+
+#define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
+{ \
+	.filter = FILTER, \
+	.rec    = { .a = va, .b = vb, .c = vc, .d = vd, \
+		    .e = ve, .f = vf, .g = vg, .h = vh }, \
+	.match  = m, \
+	.not_visited = nvisit, \
+}
+#define YES 1
+#define NO  0
+
+static struct test_filter_data_t {
+	char *filter;
+	struct ftrace_raw_ftrace_test_filter rec;
+	int match;
+	char *not_visited;
+} test_filter_data[] = {
+#define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
+	       "e == 1 && f == 1 && g == 1 && h == 1"
+	DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, ""),
+	DATA_REC(NO,  0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
+	DATA_REC(NO,  1, 1, 1, 1, 1, 1, 1, 0, ""),
+#undef FILTER
+#define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
+	       "e == 1 || f == 1 || g == 1 || h == 1"
+	DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
+	DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, ""),
+	DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
+#undef FILTER
+#define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
+	       "(e == 1 || f == 1) && (g == 1 || h == 1)"
+	DATA_REC(NO,  0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
+	DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
+	DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
+	DATA_REC(NO,  1, 0, 1, 0, 0, 1, 0, 0, "bd"),
+#undef FILTER
+#define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
+	       "(e == 1 && f == 1) || (g == 1 && h == 1)"
+	DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
+	DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, ""),
+	DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
+#undef FILTER
+#define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
+	       "(e == 1 && f == 1) || (g == 1 && h == 1)"
+	DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
+	DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
+	DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, ""),
+#undef FILTER
+#define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
+	       "(e == 1 || f == 1)) && (g == 1 || h == 1)"
+	DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
+	DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
+	DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
+#undef FILTER
+#define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
+	       "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
+	DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
+	DATA_REC(NO,  0, 1, 0, 1, 0, 1, 0, 1, ""),
+	DATA_REC(NO,  1, 0, 1, 0, 1, 0, 1, 0, ""),
+#undef FILTER
+#define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
+	       "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
+	DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
+	DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
+	DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
+};
+
+#undef DATA_REC
+#undef FILTER
+#undef YES
+#undef NO
+
+#define DATA_CNT (sizeof(test_filter_data)/sizeof(struct test_filter_data_t))
+
+static int test_pred_visited;
+
+static int test_pred_visited_fn(struct filter_pred *pred, void *event)
+{
+	struct ftrace_event_field *field = pred->field;
+
+	test_pred_visited = 1;
+	printk(KERN_INFO "\npred visited %s\n", field->name);
+	return 1;
+}
+
+static int test_walk_pred_cb(enum move_type move, struct filter_pred *pred,
+			     int *err, void *data)
+{
+	char *fields = data;
+
+	if ((move == MOVE_DOWN) &&
+	    (pred->left == FILTER_PRED_INVALID)) {
+		struct ftrace_event_field *field = pred->field;
+
+		if (!field) {
+			WARN(1, "all leafs should have field defined");
+			return WALK_PRED_DEFAULT;
+		}
+		if (!strchr(fields, *field->name))
+			return WALK_PRED_DEFAULT;
+
+		WARN_ON(!pred->fn);
+		pred->fn = test_pred_visited_fn;
+	}
+	return WALK_PRED_DEFAULT;
+}
+
+static __init int ftrace_test_event_filter(void)
+{
+	int i;
+
+	printk(KERN_INFO "Testing ftrace filter: ");
+
+	for (i = 0; i < DATA_CNT; i++) {
+		struct event_filter *filter = NULL;
+		struct test_filter_data_t *d = &test_filter_data[i];
+		int err;
+
+		err = test_get_filter(d->filter, &event_ftrace_test_filter,
+				      &filter);
+		if (err) {
+			printk(KERN_INFO
+			       "Failed to get filter for '%s', err %d\n",
+			       d->filter, err);
+			break;
+		}
+
+		if (*d->not_visited)
+			walk_pred_tree(filter->preds, filter->root,
+				       test_walk_pred_cb,
+				       d->not_visited);
+
+		test_pred_visited = 0;
+		err = filter_match_preds(filter, &d->rec);
+
+		__free_filter(filter);
+
+		if (test_pred_visited) {
+			printk(KERN_INFO
+			       "Failed, unwanted pred visited for filter %s\n",
+			       d->filter);
+			break;
+		}
+
+		if (err != d->match) {
+			printk(KERN_INFO
+			       "Failed to match filter '%s', expected %d\n",
+			       d->filter, d->match);
+			break;
+		}
+	}
+
+	if (i == DATA_CNT)
+		printk(KERN_CONT "OK\n");
+
+	return 0;
+}
+
+late_initcall(ftrace_test_event_filter);
+
+#endif /* CONFIG_FTRACE_STARTUP_TEST */