[PATCH 1/2] perf tools: Prompt error message for wrong terms of hw/sw events

[He Kuang]

Prompt proper error message when wrong config terms is specificed for
hw/sw type perf events. Currently, unknown terms is not reported as an
error because pmu events have valid terms in sysfs. But for hw/sw
events, valid config terms are fixed and it should be reported if
wrong terms are given.

Before this patch:

  $ perf record -e 'cpu-clock/freq=200/' -a sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.028 MB perf.data (202 samples) ]

  $ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.042 MB perf.data (506 samples) ]

After this patch:

  $ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
  event syntax error: 'cpu-clock/freqx=200/'
                                 \___ unknown term

  valid terms: config,config1,config2,name,period,freq,branch_type,time,call-graph,stack-size

  Run 'perf list' for a list of valid events

   usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -e, --event <event>   event selector. use 'perf list' to list available events

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
---
 tools/perf/util/parse-events.c | 60 +++++++++++++++++++++++++++++++++++-------
 tools/perf/util/parse-events.h |  1 +
 tools/perf/util/pmu.c          | 35 +++++++++---------------
 3 files changed, 63 insertions(+), 33 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 61c2bc2..f624b99 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -599,7 +599,11 @@ static int check_type_val(struct parse_events_term *term,
 	return -EINVAL;
 }
 
-static int config_term(struct perf_event_attr *attr,
+typedef int config_term_func_t(struct perf_event_attr *attr,
+			       struct parse_events_term *term,
+			       struct parse_events_error *err);
+
+static int config_term_common(struct perf_event_attr *attr,
 		       struct parse_events_term *term,
 		       struct parse_events_error *err)
 {
@@ -610,12 +614,6 @@ do {									   \
 } while (0)
 
 	switch (term->type_term) {
-	case PARSE_EVENTS__TERM_TYPE_USER:
-		/*
-		 * Always succeed for sysfs terms, as we dont know
-		 * at this point what type they need to have.
-		 */
-		return 0;
 	case PARSE_EVENTS__TERM_TYPE_CONFIG:
 		CHECK_TYPE_VAL(NUM);
 		attr->config = term->val.num;
@@ -658,6 +656,9 @@ do {									   \
 		CHECK_TYPE_VAL(STR);
 		break;
 	default:
+		err->str = strdup("unknown term");
+		err->idx = term->err_term;
+		err->help = parse_events_formats_error_string(NULL);
 		return -EINVAL;
 	}
 
@@ -665,9 +666,24 @@ do {									   \
 #undef CHECK_TYPE_VAL
 }
 
+static int config_term_pmu(struct perf_event_attr *attr,
+		       struct parse_events_term *term,
+		       struct parse_events_error *err)
+{
+	if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER)
+		/*
+		 * Always succeed for sysfs terms, as we dont know
+		 * at this point what type they need to have.
+		 */
+		return 0;
+	else
+		return config_term_common(attr, term, err);
+}
+
 static int config_attr(struct perf_event_attr *attr,
 		       struct list_head *head,
-		       struct parse_events_error *err)
+		       struct parse_events_error *err,
+		       config_term_func_t config_term)
 {
 	struct parse_events_term *term;
 
@@ -735,7 +751,8 @@ int parse_events_add_numeric(struct parse_events_evlist *data,
 	attr.config = config;
 
 	if (head_config) {
-		if (config_attr(&attr, head_config, data->error))
+		if (config_attr(&attr, head_config, data->error,
+				config_term_common))
 			return -EINVAL;
 
 		if (get_config_terms(head_config, &config_terms))
@@ -795,7 +812,7 @@ int parse_events_add_pmu(struct parse_events_evlist *data,
 	 * Configure hardcoded terms first, no need to check
 	 * return value when called with fail == 0 ;)
 	 */
-	if (config_attr(&attr, head_config, data->error))
+	if (config_attr(&attr, head_config, data->error, config_term_pmu))
 		return -EINVAL;
 
 	if (get_config_terms(head_config, &config_terms))
@@ -1861,3 +1878,26 @@ void parse_events_evlist_error(struct parse_events_evlist *data,
 	err->str = strdup(str);
 	WARN_ONCE(!err->str, "WARNING: failed to allocate error string");
 }
+
+char *parse_events_formats_error_string(char *additional_terms)
+{
+	char *str;
+	static const char *static_terms = "config,config1,config2,name,"
+					  "period,freq,branch_type,time,"
+					  "call-graph,stack-size\n";
+
+	/* valid terms */
+	if (additional_terms) {
+		if (!asprintf(&str, "valid terms: %s,%s",
+			      additional_terms, static_terms))
+			goto fail;
+		free(additional_terms);
+	} else {
+		if (!asprintf(&str, "valid terms: %s", static_terms))
+			goto fail;
+	}
+	return str;
+
+fail:
+	return NULL;
+}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index ffee7ec..c7b904a 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -156,5 +156,6 @@ int print_hwcache_events(const char *event_glob, bool name_only);
 extern int is_valid_tracepoint(const char *event_string);
 
 int valid_event_mount(const char *eventfs);
+char *parse_events_formats_error_string(char *additional_terms);
 
 #endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 89c91a1..ea3dd04 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -626,38 +626,26 @@ static int pmu_resolve_param_term(struct parse_events_term *term,
 	return -1;
 }
 
-static char *formats_error_string(struct list_head *formats)
+static char *pmu_formats_string(struct list_head *formats)
 {
 	struct perf_pmu_format *format;
-	char *err, *str;
-	static const char *static_terms = "config,config1,config2,name,"
-					  "period,freq,branch_type,time,"
-					  "call-graph,stack-size\n";
+	char *str;
+	struct strbuf buf;
 	unsigned i = 0;
 
-	if (!asprintf(&str, "valid terms:"))
+	if (!formats)
 		return NULL;
 
+	strbuf_init(&buf, 0);
 	/* sysfs exported terms */
-	list_for_each_entry(format, formats, list) {
-		char c = i++ ? ',' : ' ';
-
-		err = str;
-		if (!asprintf(&str, "%s%c%s", err, c, format->name))
-			goto fail;
-		free(err);
-	}
+	list_for_each_entry(format, formats, list)
+		strbuf_addf(&buf, i++ ? ",%s" : "%s",
+			    format->name);
 
-	/* static terms */
-	err = str;
-	if (!asprintf(&str, "%s,%s", err, static_terms))
-		goto fail;
+	str = strbuf_detach(&buf, NULL);
+	strbuf_release(&buf);
 
-	free(err);
 	return str;
-fail:
-	free(err);
-	return NULL;
 }
 
 /*
@@ -695,7 +683,8 @@ static int pmu_config_term(struct list_head *formats,
 		if (err) {
 			err->idx  = term->err_term;
 			err->str  = strdup("unknown term");
-			err->help = formats_error_string(formats);
+			err->help = parse_events_formats_error_string(
+				pmu_formats_string(formats));
 		}
 		return -EINVAL;
 	}
-- 
1.8.5.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/