[v2,05/12] perf parse-events: Add parse_uid_filter helper

Commit Message

Ian Rogers April 10, 2025, 5:36 p.m. UTC

Add parse_uid_filter filter as a helper to parse_filter, that
constructs a uid filter string. As uid filters don't work with
tracepoint filters, add a is_possible_tp_filter function so the
tracepoint filter isn't attempted for tracepoint evsels.

Signed-off-by: Ian Rogers <[e-mail]>
---
 tools/perf/util/parse-events.c | 19 ++++++++++++++++++-
 tools/perf/util/parse-events.h |  1 +
 2 files changed, 19 insertions(+), 1 deletion(-)

Patch

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index ad5b40843b18..08ade3d70bc1 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2456,6 +2456,12 @@  foreach_evsel_in_last_glob(struct evlist *evlist,
 	return 0;
 }
 
+/* Will a tracepoint filter work for str or should a BPF filter be used? */
+static bool is_possible_tp_filter(const char *str)
+{
+	return strstr(str, "uid") == NULL;
+}
+
 static int set_filter(struct evsel *evsel, const void *arg)
 {
 	const char *str = arg;
@@ -2468,7 +2474,7 @@  static int set_filter(struct evsel *evsel, const void *arg)
 		return -1;
 	}
 
-	if (evsel->core.attr.type == PERF_TYPE_TRACEPOINT) {
+	if (evsel->core.attr.type == PERF_TYPE_TRACEPOINT && is_possible_tp_filter(str)) {
 		if (evsel__append_tp_filter(evsel, str) < 0) {
 			fprintf(stderr,
 				"not enough memory to hold filter string\n");
@@ -2504,6 +2510,17 @@  int parse_filter(const struct option *opt, const char *str,
 					  (const void *)str);
 }
 
+int parse_uid_filter(struct evlist *evlist, uid_t uid)
+{
+	struct option opt = {
+		.value = &evlist,
+	};
+	char buf[128];
+
+	snprintf(buf, sizeof(buf), "uid == %d", uid);
+	return parse_filter(&opt, buf, /*unset=*/0);
+}
+
 static int add_exclude_perf_filter(struct evsel *evsel,
 				   const void *arg __maybe_unused)
 {
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index e176a34ab088..289afd42d642 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -45,6 +45,7 @@  static inline int parse_events(struct evlist *evlist, const char *str,
 int parse_event(struct evlist *evlist, const char *str);
 
 int parse_filter(const struct option *opt, const char *str, int unset);
+int parse_uid_filter(struct evlist *evlist, uid_t uid);
 int exclude_perf(const struct option *opt, const char *arg, int unset);
 
 enum parse_events__term_val_type {