linux-kernel - [PATCH v1 09/17] perf c2c: Clean up some defensive gets and make asan clean

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Message-ID: <20251122081929.7588-10-irogers@google.com>
Date: Sat, 22 Nov 2025 00:19:21 -0800
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>, 
	James Clark <james.clark@...aro.org>, Collin Funk <collin.funk1@...il.com>, 
	Dmitry Vyukov <dvyukov@...gle.com>, Andi Kleen <ak@...ux.intel.com>, 
	Thomas Falcon <thomas.falcon@...el.com>, Leo Yan <leo.yan@....com>, 
	Yicong Yang <yangyicong@...ilicon.com>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	"Masami Hiramatsu (Google)" <mhiramat@...nel.org>, Stephen Brennan <stephen.s.brennan@...cle.com>, 
	Haibo Xu <haibo1.xu@...el.com>, linux-kernel@...r.kernel.org, 
	linux-perf-users@...r.kernel.org
Subject: [PATCH v1 09/17] perf c2c: Clean up some defensive gets and make asan clean

To deal with histogram code that had missing gets the c2c code had
some defensive gets. Those other issues were cleaned up by the
reference count checker, clean them up for the c2c command here.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/builtin-c2c.c | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index 14c3823f8fed..d390ae4e3ec8 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -322,7 +322,7 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
 	struct c2c_stats stats = { .nr_entries = 0, };
 	struct hist_entry *he;
 	struct addr_location al;
-	struct mem_info *mi, *mi_dup;
+	struct mem_info *mi = NULL;
 	struct callchain_cursor *cursor;
 	int ret;
 
@@ -349,20 +349,15 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
 		goto out;
 	}
 
-	/*
-	 * The mi object is released in hists__add_entry_ops,
-	 * if it gets sorted out into existing data, so we need
-	 * to take the copy now.
-	 */
-	mi_dup = mem_info__get(mi);
-
 	c2c_decode_stats(&stats, mi);
 
 	he = hists__add_entry_ops(&c2c_hists->hists, &c2c_entry_ops,
 				  &al, NULL, NULL, mi, NULL,
 				  sample, true);
-	if (he == NULL)
-		goto free_mi;
+	if (he == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	c2c_he = container_of(he, struct c2c_hist_entry, he);
 	c2c_add_stats(&c2c_he->stats, &stats);
@@ -393,17 +388,19 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
 		int cpu = sample->cpu == (unsigned int) -1 ? 0 : sample->cpu;
 		int node = c2c.cpu2node[cpu];
 
-		mi = mi_dup;
-
 		c2c_hists = he__get_c2c_hists(he, c2c.cl_sort, 2, machine->env);
-		if (!c2c_hists)
-			goto free_mi;
+		if (!c2c_hists) {
+			ret = -ENOMEM;
+			goto out;
+		}
 
 		he = hists__add_entry_ops(&c2c_hists->hists, &c2c_entry_ops,
 					  &al, NULL, NULL, mi, NULL,
 					  sample, true);
-		if (he == NULL)
-			goto free_mi;
+		if (he == NULL) {
+			ret = -ENOMEM;
+			goto out;
+		}
 
 		c2c_he = container_of(he, struct c2c_hist_entry, he);
 		c2c_add_stats(&c2c_he->stats, &stats);
@@ -421,14 +418,9 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
 	}
 
 out:
+	mem_info__put(mi);
 	addr_location__exit(&al);
 	return ret;
-
-free_mi:
-	mem_info__put(mi_dup);
-	mem_info__put(mi);
-	ret = -ENOMEM;
-	goto out;
 }
 
 static const char * const c2c_usage[] = {
-- 
2.52.0.rc2.455.g230fcf2819-goog