perf parser: Improve error message for PMU address filters

--filter option should follow a -e tracepoint or HW tracer option

This patch improves the error message of the perf events parser when the PMU hardware does not support address filters.

Previously, the perf returned the following error:

Quoted 1 line

--filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.

Signed-off-by Jack Henschel <[email protected]>

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 -4

index f44aeba51d1f..672b6d9423e9 100644
@@ -1833,8 +1833,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -1856,8 +1859,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -1866,12 +1872,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 

Quoted 61 lines

This patch improves the error message of the perf events parser when the PMU hardware does not support address filters.

Previously, the perf returned the following error:

Quoted 1 line

--filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line, which is not true. Rather, notify the user that the CPU does not have support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.

Signed-off-by Jack Henschel <[email protected]>

---
 tools/perf/util/parse-events.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

tools/perf/util/parse-events.c +10 -10

index f44aeba51d1f..672b6d9423e9 100644
@@ -1833,8 +1833,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	int nr_addr_filters = 0;
 	struct perf_pmu *pmu = NULL;
 
-	if (evsel == NULL)
-		goto err;
+	if (evsel == NULL) {
+		fprintf(stderr,
+			"--filter option should follow a -e tracepoint or HW tracer option\n");
+		return -1;
+	}
 
 	if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
 		if (perf_evsel__append_tp_filter(evsel, str) < 0) {

@@ -1856,8 +1859,11 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 		perf_pmu__scan_file(pmu, "nr_addr_filters",
 				    "%d", &nr_addr_filters);
 
-	if (!nr_addr_filters)
-		goto err;
+	if (!nr_addr_filters) {
+		fprintf(stderr,
+			"This CPU does not support address filtering\n");
+		return -1;
+	}
 
 	if (perf_evsel__append_addr_filter(evsel, str) < 0) {
 		fprintf(stderr,

@@ -1866,12 +1872,6 @@ static int set_filter(struct perf_evsel *evsel, const void *arg)
 	}
 
 	return 0;
-
-err:
-	fprintf(stderr,
-		"--filter option should follow a -e tracepoint or HW tracer option\n");
-
-	return -1;
 }
 

tools/perf/util/parse-events.c static int set_filter(struct perf_evsel *evsel, const void *arg) · line 1877

Quoted 2 lines

tools/perf/util/parse-events.c +0 -0

 int parse_filter(const struct option *opt, const char *str,

Is there any interest in this patch? Did it get lost?

Quoted 2 lines

For example, Intel chips based on the Broadwell micro-archticture have the Intel PT PMU, but do not support address filtering.