[PATCH 6.1 672/798] perf lock: Dynamically allocate lockhash_table

[Greg Kroah-Hartman]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ian Rogers <irogers@xxxxxxxxxx>

[ Upstream commit eef4fee5e52071d563d9a851df1c09869215ee15 ]

lockhash_table is 32,768 bytes in .bss, make it a memory allocation so
that the space is freed for non-lock perf commands.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230526183401.2326121-10-irogers@xxxxxxxxxx
Cc: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Yang Jihong <yangjihong1@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Stable-dep-of: 1a5efc9e13f3 ("libsubcmd: Don't free the usage string")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/perf/builtin-lock.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 470106643ed52..28fa76ecc0822 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -45,7 +45,7 @@ static struct target target;
 #define LOCKHASH_BITS		12
 #define LOCKHASH_SIZE		(1UL << LOCKHASH_BITS)
 
-static struct hlist_head lockhash_table[LOCKHASH_SIZE];
+static struct hlist_head *lockhash_table;
 
 #define __lockhashfn(key)	hash_long((unsigned long)key, LOCKHASH_BITS)
 #define lockhashentry(key)	(lockhash_table + __lockhashfn((key)))
@@ -1645,16 +1645,22 @@ static int __cmd_contention(int argc, const char **argv)
 	};
 	struct lock_contention con = {
 		.target = &target,
-		.result = &lockhash_table[0],
 		.map_nr_entries = bpf_map_entries,
 		.max_stack = max_stack_depth,
 		.stack_skip = stack_skip,
 	};
 
+	lockhash_table = calloc(LOCKHASH_SIZE, sizeof(*lockhash_table));
+	if (!lockhash_table)
+		return -ENOMEM;
+
+	con.result = &lockhash_table[0];
+
 	session = perf_session__new(use_bpf ? NULL : &data, &eops);
 	if (IS_ERR(session)) {
 		pr_err("Initializing perf session failed\n");
-		return PTR_ERR(session);
+		err = PTR_ERR(session);
+		goto out_delete;
 	}
 
 	con.machine = &session->machines.host;
@@ -1755,6 +1761,7 @@ static int __cmd_contention(int argc, const char **argv)
 	evlist__delete(con.evlist);
 	lock_contention_finish();
 	perf_session__delete(session);
+	zfree(&lockhash_table);
 	return err;
 }
 
@@ -1946,6 +1953,10 @@ int cmd_lock(int argc, const char **argv)
 	unsigned int i;
 	int rc = 0;
 
+	lockhash_table = calloc(LOCKHASH_SIZE, sizeof(*lockhash_table));
+	if (!lockhash_table)
+		return -ENOMEM;
+
 	for (i = 0; i < LOCKHASH_SIZE; i++)
 		INIT_HLIST_HEAD(lockhash_table + i);
 
@@ -1967,7 +1978,7 @@ int cmd_lock(int argc, const char **argv)
 		rc = __cmd_report(false);
 	} else if (!strcmp(argv[0], "script")) {
 		/* Aliased to 'perf script' */
-		return cmd_script(argc, argv);
+		rc = cmd_script(argc, argv);
 	} else if (!strcmp(argv[0], "info")) {
 		if (argc) {
 			argc = parse_options(argc, argv,
@@ -1996,5 +2007,6 @@ int cmd_lock(int argc, const char **argv)
 		usage_with_options(lock_usage, lock_options);
 	}
 
+	zfree(&lockhash_table);
 	return rc;
 }
-- 
2.43.0