perf thread: Add reference count checking

Modify struct declaration and accessor functions for the reference
count checkers additional layer of indirection. Make sure pid_cmp in
builtin-sched.c uses the underlying/original struct in pointer
arithmetic, and not the temporary get/put indirection.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brian Robbins <brianrob@linux.microsoft.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Babrou <ivan@cloudflare.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Wenyu Liu <liuwenyu7@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Ye Xingchen <ye.xingchen@zte.com.cn>
Cc: Yuan Can <yuancan@huawei.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230608232823.4027869-8-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index bee4ac1051ee..0b166404c5c3 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -41,9 +41,10 @@ struct thread *thread__new(pid_t pid, pid_t tid)
 {
 	char *comm_str;
 	struct comm *comm;
-	struct thread *thread = zalloc(sizeof(*thread));
+	RC_STRUCT(thread) *_thread = zalloc(sizeof(*_thread));
+	struct thread *thread;
 
-	if (thread != NULL) {
+	if (ADD_RC_CHK(thread, _thread) != NULL) {
 		thread__set_pid(thread, pid);
 		thread__set_tid(thread, tid);
 		thread__set_ppid(thread, -1);
@@ -68,7 +69,7 @@ struct thread *thread__new(pid_t pid, pid_t tid)
 		list_add(&comm->list, thread__comm_list(thread));
 		refcount_set(thread__refcnt(thread), 1);
 		/* Thread holds first ref to nsdata. */
-		thread->nsinfo = nsinfo__new(pid);
+		RC_CHK_ACCESS(thread)->nsinfo = nsinfo__new(pid);
 		srccode_state_init(thread__srccode_state(thread));
 	}
 
@@ -105,26 +106,31 @@ void thread__delete(struct thread *thread)
 	}
 	up_write(thread__comm_lock(thread));
 
-	nsinfo__zput(thread->nsinfo);
+	nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo);
 	srccode_state_free(thread__srccode_state(thread));
 
 	exit_rwsem(thread__namespaces_lock(thread));
 	exit_rwsem(thread__comm_lock(thread));
 	thread__free_stitch_list(thread);
-	free(thread);
+	RC_CHK_FREE(thread);
 }
 
 struct thread *thread__get(struct thread *thread)
 {
-	if (thread)
+	struct thread *result;
+
+	if (RC_CHK_GET(result, thread))
 		refcount_inc(thread__refcnt(thread));
-	return thread;
+
+	return result;
 }
 
 void thread__put(struct thread *thread)
 {
 	if (thread && refcount_dec_and_test(thread__refcnt(thread)))
 		thread__delete(thread);
+	else
+		RC_CHK_PUT(thread);
 }
 
 static struct namespaces *__thread__namespaces(struct thread *thread)