[PATCH 7/9] perf c2c: Fix hist entry and format list leaks in c2c_he_free()
From: Arnaldo Carvalho de Melo
Date: Mon Jun 15 2026 - 22:29:49 EST
From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
c2c_he_free() calls hists__delete_entries() which only walks the
output-sorted entries tree. During c2c resort, when cacheline entries
are merged and the redundant entry is freed, the inner hists have not
been output-resorted yet, so hists->entries is empty. The actual inner
hist_entry objects live in entries_in_array[] and entries_collapsed,
which are never walked, leaking all inner hist_entry objects for every
merged cacheline.
Additionally, the dynamically allocated format entries on hists->list
are never unregistered or freed.
Fix both issues by switching to hists__delete_all_entries() which walks
all rb_root trees, and calling perf_hpp__reset_output_field() to clean
up format entries.
Fixes: bf0e0d407ea09ce5 ("perf c2c report: Add sample processing")
Reported-by: sashiko-bot <sashiko-bot@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Assisted-by: Claude <noreply@xxxxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-c2c.c | 2 +-
tools/perf/util/hist.c | 2 +-
tools/perf/util/hist.h | 1 +
3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index eabb922ef295ef86..c9584dbedf77afe8 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -184,7 +184,7 @@ static void c2c_he_free(void *he)
c2c_he = container_of(he, struct c2c_hist_entry, he);
if (c2c_he->hists) {
- hists__delete_entries(&c2c_he->hists->hists);
+ hists__delete_all_entries(&c2c_he->hists->hists);
perf_hpp__reset_output_field(&c2c_he->hists->list);
zfree(&c2c_he->hists);
}
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index df978c996b6c2262..c93915625ee75de1 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -3041,7 +3041,7 @@ static void hists__delete_remaining_entries(struct rb_root_cached *root)
}
}
-static void hists__delete_all_entries(struct hists *hists)
+void hists__delete_all_entries(struct hists *hists)
{
hists__delete_entries(hists);
hists__delete_remaining_entries(&hists->entries_in_array[0]);
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 8fb89d81ef069d95..b830cbe7f95bf597 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -391,6 +391,7 @@ int hists__collapse_resort(struct hists *hists, struct ui_progress *prog);
void hists__decay_entries(struct hists *hists, bool zap_user, bool zap_kernel);
void hists__delete_entries(struct hists *hists);
+void hists__delete_all_entries(struct hists *hists);
void hists__output_recalc_col_len(struct hists *hists, int max_rows);
struct hist_entry *hists__get_entry(struct hists *hists, int idx);
--
2.54.0