[PATCH v2] perf inject: Inject build ids for entire call chain

Ian Rogers
2024-08-12T22:41:24Z

The DSO build id is injected when the dso is first encountered but the
checking for first encountered only looks at the sample->ip not the
entire callchain. Use the callchain logic to ensure all build ids are
inserted.

Add a for_each callback style API to callchain with
sample__for_each_callchain_node. Possibly in the future such an API
can avoid the overhead of constructing the call chain list.

Fixes: 454c407ec17a ("perf: add perf-inject builtin")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
---
v2. Rebase and add Namhyung's acked-by.
---
tools/perf/builtin-inject.c | 31 +++++++++++++++++++++++++++++++
tools/perf/util/callchain.c | 35 +++++++++++++++++++++++++++++++++++
tools/perf/util/callchain.h | 6 ++++++
3 files changed, 72 insertions(+)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index ef9cba173dd2..a35bde3f3c09 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -743,6 +743,29 @@ static int dso__inject_build_id(struct dso *dso, const struct perf_tool *tool,
return 0;
}

+struct mark_dso_hit_args {
+ const struct perf_tool *tool;
+ struct machine *machine;
+ u8 cpumode;
+};
+
+static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data)
+{
+ struct mark_dso_hit_args *args = data;
+ struct map *map = node->ms.map;
+
+ if (map) {
+ struct dso *dso = map__dso(map);
+
+ if (dso && !dso__hit(dso)) {
+ dso__set_hit(dso);
+ dso__inject_build_id(dso, args->tool, args->machine,
+ args->cpumode, map__flags(map));
+ }
+ }
+ return 0;
+}
+
int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *event,
struct perf_sample *sample,
struct evsel *evsel __maybe_unused,
@@ -750,6 +773,11 @@ int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *e
{
struct addr_location al;
struct thread *thread;
+ struct mark_dso_hit_args args = {
+ .tool = tool,
+ .machine = machine,
+ .cpumode = sample->cpumode,
+ };

addr_location__init(&al);
thread = machine__findnew_thread(machine, sample->pid, sample->tid);
@@ -769,6 +797,9 @@ int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *e
}
}

+ sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH,
+ mark_dso_hit_callback, &args);
+
thread__put(thread);
repipe:
perf_event__repipe(tool, event, sample, machine);
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 6d075648d2cc..0d608e875fe9 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1797,3 +1797,38 @@ s64 callchain_avg_cycles(struct callchain_node *cnode)

return cycles;
}
+
+int sample__for_each_callchain_node(struct thread *thread, struct evsel *evsel,
+ struct perf_sample *sample, int max_stack,
+ callchain_iter_fn cb, void *data)
+{
+ struct callchain_cursor *cursor = get_tls_callchain_cursor();
+ int ret;
+
+ if (!cursor)
+ return -ENOMEM;
+
+ /* Fill in the callchain. */
+ ret = thread__resolve_callchain(thread, cursor, evsel, sample,
+ /*parent=*/NULL, /*root_al=*/NULL,
+ max_stack);
+ if (ret)
+ return ret;
+
+ /* Switch from writing the callchain to reading it. */
+ callchain_cursor_commit(cursor);
+
+ while (1) {
+ struct callchain_cursor_node *node = callchain_cursor_current(cursor);
+
+ if (!node)
+ break;
+
+ ret = cb(node, data);
+ if (ret)
+ return ret;
+
+ callchain_cursor_advance(cursor);
+ }
+ return 0;
+}
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index d5c66345ae31..76891f8e2373 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -311,4 +311,10 @@ u64 callchain_total_hits(struct hists *hists);

s64 callchain_avg_cycles(struct callchain_node *cnode);

+typedef int (*callchain_iter_fn)(struct callchain_cursor_node *node, void *data);
+
+int sample__for_each_callchain_node(struct thread *thread, struct evsel *evsel,
+ struct perf_sample *sample, int max_stack,
+ callchain_iter_fn cb, void *data);
+
#endif /* __PERF_CALLCHAIN_H */
--
2.46.0.76.ge559c4bf1a-goog