[PATCH v11 16/19] perf env: Add mutex to protect lazy environment initialization

[Ian Rogers]

Introduce a mutex to 'struct perf_env' to safely protect lazy
metadata setup, such as os_release or e_machine resolution,
preventing concurrent initialization data races and memory leaks
during multi-threaded profiling or symbol loading.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/env.c | 3 +++
 tools/perf/util/env.h | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 28c54c58193e..4de07cc7ef5d 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -250,6 +250,8 @@ void perf_env__exit(struct perf_env *env)
 {
 	int i, j;
 
+	mutex_destroy(&env->lock);
+
 	perf_env__purge_bpf(env);
 	perf_env__purge_cgroups(env);
 	zfree(&env->hostname);
@@ -307,6 +309,7 @@ void perf_env__init(struct perf_env *env)
 	init_rwsem(&env->bpf_progs.lock);
 #endif
 	env->kernel_is_64_bit = -1;
+	mutex_init(&env->lock);
 }
 
 static void perf_env__init_kernel_mode(struct perf_env *env)
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 83e74328798f..6aaf80c640bd 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -6,6 +6,7 @@
 #include <linux/rbtree.h>
 #include "cpumap.h"
 #include "rwsem.h"
+#include "mutex.h"
 
 struct perf_cpu_map;
 
@@ -156,6 +157,8 @@ struct perf_env {
 		 */
 		bool	enabled;
 	} clock;
+	/* Protects lazy environment initialization (e.g. os_release, e_machine). */
+	struct mutex		lock;
 };
 
 enum perf_compress_type {
-- 
2.54.0.929.g9b7fa37559-goog