[PATCH v2 07/26] perf thread: Add reference count checking

From: Ian Rogers <irogers@google.com>
To: John Garry <john.g.garry@oracle.com>,
	Will Deacon <will@kernel.org>, James Clark <james.clark@arm.com>,
	Mike Leach <mike.leach@linaro.org>, Leo Yan <leo.yan@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	German Gomez <german.gomez@arm.com>,
	Ali Saidi <alisaidi@amazon.com>,
	Jing Zhang <renyu.zj@linux.alibaba.com>,
	Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	ye xingchen <ye.xingchen@zte.com.cn>,
	Liam Howlett <liam.howlett@oracle.com>,
	Dmitrii Dolgov <9erthalion6@gmail.com>,
	Yang Jihong <yangjihong1@huawei.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>,
	Changbin Du <changbin.du@huawei.com>,
	Ravi Bangoria <ravi.bangoria@amd.com>,
	Sean Christopherson <seanjc@google.com>,
	Andi Kleen <ak@linux.intel.com>,
	"Steinar H. Gunderson" <sesse@google.com>,
	Yuan Can <yuancan@huawei.com>,
	Brian Robbins <brianrob@linux.microsoft.com>,
	liuwenyu <liuwenyu7@huawei.com>,
	Ivan Babrou <ivan@cloudflare.com>,
	Fangrui Song <maskray@google.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-perf-users@vger.kernel.org, coresight@lists.linaro.org
Subject: [PATCH v2 07/26] perf thread: Add reference count checking
Date: Thu,  8 Jun 2023 16:28:04 -0700	[thread overview]
Message-ID: <20230608232823.4027869-8-irogers@google.com> (raw)
In-Reply-To: <20230608232823.4027869-1-irogers@google.com>

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>
---
 tools/perf/builtin-sched.c    |  4 +-
 tools/perf/tests/hists_link.c |  2 +-
 tools/perf/ui/hist.c          |  5 ++-
 tools/perf/util/hist.c        |  2 +-
 tools/perf/util/machine.c     |  2 +-
 tools/perf/util/sort.c        |  2 +-
 tools/perf/util/thread.c      | 20 +++++----
 tools/perf/util/thread.h      | 79 ++++++++++++++++++-----------------
 8 files changed, 63 insertions(+), 53 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index c75ad82a6729..cd79068200e5 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1385,7 +1385,7 @@ static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
 {
 	pid_t l_tid, r_tid;
 
-	if (l->thread == r->thread)
+	if (RC_CHK_ACCESS(l->thread) == RC_CHK_ACCESS(r->thread))
 		return 0;
 	l_tid = thread__tid(l->thread);
 	r_tid = thread__tid(r->thread);
@@ -1393,7 +1393,7 @@ static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
 		return -1;
 	if (l_tid > r_tid)
 		return 1;
-	return (int)(l->thread - r->thread);
+	return (int)(RC_CHK_ACCESS(l->thread) - RC_CHK_ACCESS(r->thread));
 }
 
 static int avg_cmp(struct work_atoms *l, struct work_atoms *r)
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 12bad8840699..2d19657ab5e0 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -148,7 +148,7 @@ static int find_sample(struct sample *samples, size_t nr_samples,
 		       struct thread *t, struct map *m, struct symbol *s)
 {
 	while (nr_samples--) {
-		if (samples->thread == t &&
+		if (RC_CHK_ACCESS(samples->thread) == RC_CHK_ACCESS(t) &&
 		    RC_CHK_ACCESS(samples->map) == RC_CHK_ACCESS(m) &&
 		    samples->sym == s)
 			return 1;
diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index f164bd26fc41..2bf959d08354 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -11,6 +11,7 @@
 #include "../util/sort.h"
 #include "../util/evsel.h"
 #include "../util/evlist.h"
+#include "../util/thread.h"
 #include "../util/util.h"
 
 /* hist period print (hpp) functions */
@@ -274,7 +275,9 @@ static int __hpp__sort_acc(struct hist_entry *a, struct hist_entry *b,
 		if (ret)
 			return ret;
 
-		if (a->thread != b->thread || !hist_entry__has_callchains(a) || !symbol_conf.use_callchain)
+		if ((a->thread == NULL ? NULL : RC_CHK_ACCESS(a->thread)) !=
+		    (b->thread == NULL ? NULL : RC_CHK_ACCESS(b->thread)) ||
+		    !hist_entry__has_callchains(a) || !symbol_conf.use_callchain)
 			return 0;
 
 		ret = b->callchain->max_depth - a->callchain->max_depth;
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index a4c1b617f6e4..dfda52d348a3 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -2124,7 +2124,7 @@ static bool hists__filter_entry_by_thread(struct hists *hists,
 					  struct hist_entry *he)
 {
 	if (hists->thread_filter != NULL &&
-	    he->thread != hists->thread_filter) {
+	    RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(hists->thread_filter)) {
 		he->filtered |= (1 << HIST_FILTER__THREAD);
 		return true;
 	}
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 9fcf357a4d53..261188766307 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2055,7 +2055,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread_rb_n
 	if (!nd)
 		nd = thread_rb_node__find(th, &threads->entries.rb_root);
 
-	if (threads->last_match == th)
+	if (threads->last_match && RC_CHK_ACCESS(threads->last_match) == RC_CHK_ACCESS(th))
 		threads__set_last_match(threads, NULL);
 
 	if (lock)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 5e45c770f91d..047c3606802f 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -128,7 +128,7 @@ static int hist_entry__thread_filter(struct hist_entry *he, int type, const void
 	if (type != HIST_FILTER__THREAD)
 		return -1;
 
-	return th && he->thread != th;
+	return th && RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(th);
 }
 
 struct sort_entry sort_thread = {
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)
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index b103992c3831..9068a21ce0fa 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -15,6 +15,7 @@
 #include "rwsem.h"
 #include "event.h"
 #include "callchain.h"
+#include <internal/rc_check.h>
 
 struct addr_location;
 struct map;
@@ -34,7 +35,7 @@ struct thread_rb_node {
 	struct thread *thread;
 };
 
-struct thread {
+DECLARE_RC_STRUCT(thread) {
 	struct maps		*maps;
 	pid_t			pid_; /* Not all tools update this */
 	pid_t			tid;
@@ -123,192 +124,192 @@ int thread__memcpy(struct thread *thread, struct machine *machine,
 
 static inline struct maps *thread__maps(struct thread *thread)
 {
-	return thread->maps;
+	return RC_CHK_ACCESS(thread)->maps;
 }
 
 static inline void thread__set_maps(struct thread *thread, struct maps *maps)
 {
-	thread->maps = maps;
+	RC_CHK_ACCESS(thread)->maps = maps;
 }
 
 static inline pid_t thread__pid(const struct thread *thread)
 {
-	return thread->pid_;
+	return RC_CHK_ACCESS(thread)->pid_;
 }
 
 static inline void thread__set_pid(struct thread *thread, pid_t pid_)
 {
-	thread->pid_ = pid_;
+	RC_CHK_ACCESS(thread)->pid_ = pid_;
 }
 
 static inline pid_t thread__tid(const struct thread *thread)
 {
-	return thread->tid;
+	return RC_CHK_ACCESS(thread)->tid;
 }
 
 static inline void thread__set_tid(struct thread *thread, pid_t tid)
 {
-	thread->tid = tid;
+	RC_CHK_ACCESS(thread)->tid = tid;
 }
 
 static inline pid_t thread__ppid(const struct thread *thread)
 {
-	return thread->ppid;
+	return RC_CHK_ACCESS(thread)->ppid;
 }
 
 static inline void thread__set_ppid(struct thread *thread, pid_t ppid)
 {
-	thread->ppid = ppid;
+	RC_CHK_ACCESS(thread)->ppid = ppid;
 }
 
 static inline int thread__cpu(const struct thread *thread)
 {
-	return thread->cpu;
+	return RC_CHK_ACCESS(thread)->cpu;
 }
 
 static inline void thread__set_cpu(struct thread *thread, int cpu)
 {
-	thread->cpu = cpu;
+	RC_CHK_ACCESS(thread)->cpu = cpu;
 }
 
 static inline int thread__guest_cpu(const struct thread *thread)
 {
-	return thread->guest_cpu;
+	return RC_CHK_ACCESS(thread)->guest_cpu;
 }
 
 static inline void thread__set_guest_cpu(struct thread *thread, int guest_cpu)
 {
-	thread->guest_cpu = guest_cpu;
+	RC_CHK_ACCESS(thread)->guest_cpu = guest_cpu;
 }
 
 static inline refcount_t *thread__refcnt(struct thread *thread)
 {
-	return &thread->refcnt;
+	return &RC_CHK_ACCESS(thread)->refcnt;
 }
 
 static inline bool thread__comm_set(const struct thread *thread)
 {
-	return thread->comm_set;
+	return RC_CHK_ACCESS(thread)->comm_set;
 }
 
 static inline void thread__set_comm_set(struct thread *thread, bool set)
 {
-	thread->comm_set = set;
+	RC_CHK_ACCESS(thread)->comm_set = set;
 }
 
 static inline int thread__var_comm_len(const struct thread *thread)
 {
-	return thread->comm_len;
+	return RC_CHK_ACCESS(thread)->comm_len;
 }
 
 static inline void thread__set_comm_len(struct thread *thread, int len)
 {
-	thread->comm_len = len;
+	RC_CHK_ACCESS(thread)->comm_len = len;
 }
 
 static inline struct list_head *thread__namespaces_list(struct thread *thread)
 {
-	return &thread->namespaces_list;
+	return &RC_CHK_ACCESS(thread)->namespaces_list;
 }
 
 static inline int thread__namespaces_list_empty(const struct thread *thread)
 {
-	return list_empty(&thread->namespaces_list);
+	return list_empty(&RC_CHK_ACCESS(thread)->namespaces_list);
 }
 
 static inline struct rw_semaphore *thread__namespaces_lock(struct thread *thread)
 {
-	return &thread->namespaces_lock;
+	return &RC_CHK_ACCESS(thread)->namespaces_lock;
 }
 
 static inline struct list_head *thread__comm_list(struct thread *thread)
 {
-	return &thread->comm_list;
+	return &RC_CHK_ACCESS(thread)->comm_list;
 }
 
 static inline struct rw_semaphore *thread__comm_lock(struct thread *thread)
 {
-	return &thread->comm_lock;
+	return &RC_CHK_ACCESS(thread)->comm_lock;
 }
 
 static inline u64 thread__db_id(const struct thread *thread)
 {
-	return thread->db_id;
+	return RC_CHK_ACCESS(thread)->db_id;
 }
 
 static inline void thread__set_db_id(struct thread *thread, u64 db_id)
 {
-	thread->db_id = db_id;
+	RC_CHK_ACCESS(thread)->db_id = db_id;
 }
 
 static inline void *thread__priv(struct thread *thread)
 {
-	return thread->priv;
+	return RC_CHK_ACCESS(thread)->priv;
 }
 
 static inline void thread__set_priv(struct thread *thread, void *p)
 {
-	thread->priv = p;
+	RC_CHK_ACCESS(thread)->priv = p;
 }
 
 static inline struct thread_stack *thread__ts(struct thread *thread)
 {
-	return thread->ts;
+	return RC_CHK_ACCESS(thread)->ts;
 }
 
 static inline void thread__set_ts(struct thread *thread, struct thread_stack *ts)
 {
-	thread->ts = ts;
+	RC_CHK_ACCESS(thread)->ts = ts;
 }
 
 static inline struct nsinfo *thread__nsinfo(struct thread *thread)
 {
-	return thread->nsinfo;
+	return RC_CHK_ACCESS(thread)->nsinfo;
 }
 
 static inline struct srccode_state *thread__srccode_state(struct thread *thread)
 {
-	return &thread->srccode_state;
+	return &RC_CHK_ACCESS(thread)->srccode_state;
 }
 
 static inline bool thread__filter(const struct thread *thread)
 {
-	return thread->filter;
+	return RC_CHK_ACCESS(thread)->filter;
 }
 
 static inline void thread__set_filter(struct thread *thread, bool filter)
 {
-	thread->filter = filter;
+	RC_CHK_ACCESS(thread)->filter = filter;
 }
 
 static inline int thread__filter_entry_depth(const struct thread *thread)
 {
-	return thread->filter_entry_depth;
+	return RC_CHK_ACCESS(thread)->filter_entry_depth;
 }
 
 static inline void thread__set_filter_entry_depth(struct thread *thread, int depth)
 {
-	thread->filter_entry_depth = depth;
+	RC_CHK_ACCESS(thread)->filter_entry_depth = depth;
 }
 
 static inline bool thread__lbr_stitch_enable(const struct thread *thread)
 {
-	return thread->lbr_stitch_enable;
+	return RC_CHK_ACCESS(thread)->lbr_stitch_enable;
 }
 
 static inline void thread__set_lbr_stitch_enable(struct thread *thread, bool en)
 {
-	thread->lbr_stitch_enable = en;
+	RC_CHK_ACCESS(thread)->lbr_stitch_enable = en;
 }
 
 static inline struct lbr_stitch	*thread__lbr_stitch(struct thread *thread)
 {
-	return thread->lbr_stitch;
+	return RC_CHK_ACCESS(thread)->lbr_stitch;
 }
 
 static inline void thread__set_lbr_stitch(struct thread *thread, struct lbr_stitch *lbrs)
 {
-	thread->lbr_stitch = lbrs;
+	RC_CHK_ACCESS(thread)->lbr_stitch = lbrs;
 }
 
 static inline bool thread__is_filtered(struct thread *thread)
-- 
2.41.0.162.gfafddb0af9-goog

