[PATCH v3 1/4] perf sched: Add missing mmap2 handler in timehist

[Ian Rogers <irogers@google.com>]

perf_sched__timehist() registers event handlers for options using the
sched->tool struct. It registers handlers for MMAP, COMM, EXIT, FORK, etc.
but completely omits registering a handler for MMAP2 events.

Failing to register both MMAP and MMAP2 handlers causes modern systems
(which primarily output MMAP2 records) to silently drop VMA map mappings.
This results in uninitialized machine/thread mapping structures, making it
impossible to resolve shared library instruction pointers (IPs) to dynamic
symbols/DSOs during timehist callchain analysis.

Fix this by correctly registering perf_event__process_mmap2 in
sched->tool inside perf_sched__timehist().

Assisted-by: Gemini-CLI:Google Gemini 3
Fixes: 5bbfec0ad93c ("perf sched: Implement timehist option")
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/builtin-sched.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 555247568e7a..241c2f808f7b 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -3299,6 +3299,7 @@ static int perf_sched__timehist(struct perf_sched *sched)
 	 */
 	sched->tool.sample	 = perf_timehist__process_sample;
 	sched->tool.mmap	 = perf_event__process_mmap;
+	sched->tool.mmap2	 = perf_event__process_mmap2;
 	sched->tool.comm	 = perf_event__process_comm;
 	sched->tool.exit	 = perf_event__process_exit;
 	sched->tool.fork	 = perf_event__process_fork;
-- 
2.54.0.545.g6539524ca2-goog