[PATCH v1 20/20] perf map/maps/thread: Changes to reference counting

From: Ian Rogers
Date: Tue Jun 06 2023 - 21:47:08 EST


Fix missed reference count gets and puts as detected with leak
sanitizer and reference count checking.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/callchain.c | 7 +++++--
tools/perf/util/event.c | 3 +++
tools/perf/util/hist.c | 6 ++++--
tools/perf/util/machine.c | 14 ++++++++------
4 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index b0dafc758173..437325d19ad3 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1065,8 +1065,10 @@ int callchain_cursor_append(struct callchain_cursor *cursor,
}

node->ip = ip;
+ maps__zput(node->ms.maps);
map__zput(node->ms.map);
node->ms = *ms;
+ node->ms.maps = maps__get(node->ms.maps);
node->ms.map = map__get(node->ms.map);
node->branch = branch;
node->nr_loop_iter = nr_loop_iter;
@@ -1114,7 +1116,8 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
{
struct machine *machine = maps__machine(node->ms.maps);

- al->maps = node->ms.maps;
+ maps__put(al->maps);
+ al->maps = maps__get(node->ms.maps);
map__put(al->map);
al->map = map__get(node->ms.map);
al->sym = node->ms.sym;
@@ -1127,7 +1130,7 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
if (al->map == NULL)
goto out;
}
- if (al->maps == machine__kernel_maps(machine)) {
+ if (RC_CHK_ACCESS(al->maps) == RC_CHK_ACCESS(machine__kernel_maps(machine))) {
if (machine__is_host(machine)) {
al->cpumode = PERF_RECORD_MISC_KERNEL;
al->level = 'k';
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 2fcfba38fc48..3860b0c74829 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -711,6 +711,9 @@ int machine__resolve(struct machine *machine, struct addr_location *al,
if (thread__is_filtered(thread))
al->filtered |= (1 << HIST_FILTER__THREAD);

+ thread__put(thread);
+ thread = NULL;
+
al->sym = NULL;
al->cpu = sample->cpu;
al->socket = -1;
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index dfda52d348a3..fb218b3e8a7c 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -450,6 +450,7 @@ static int hist_entry__init(struct hist_entry *he,
memset(&he->stat, 0, sizeof(he->stat));
}

+ he->ms.maps = maps__get(he->ms.maps);
he->ms.map = map__get(he->ms.map);

if (he->branch_info) {
@@ -497,7 +498,7 @@ static int hist_entry__init(struct hist_entry *he,
}

INIT_LIST_HEAD(&he->pairs.node);
- thread__get(he->thread);
+ he->thread = thread__get(he->thread);
he->hroot_in = RB_ROOT_CACHED;
he->hroot_out = RB_ROOT_CACHED;

@@ -523,6 +524,7 @@ static int hist_entry__init(struct hist_entry *he,
map__put(he->mem_info->daddr.ms.map);
}
err:
+ maps__zput(he->ms.maps);
map__zput(he->ms.map);
zfree(&he->stat_acc);
return -ENOMEM;
@@ -611,7 +613,6 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists,
* keys were used.
*/
cmp = hist_entry__cmp(he, entry);
-
if (!cmp) {
if (sample_self) {
he_stat__add_period(&he->stat, period);
@@ -1309,6 +1310,7 @@ void hist_entry__delete(struct hist_entry *he)
struct hist_entry_ops *ops = he->ops;

thread__zput(he->thread);
+ maps__zput(he->ms.maps);
map__zput(he->ms.map);

if (he->branch_info) {
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 359ef6b4e840..16dc49876e87 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -539,7 +539,7 @@ static void machine__update_thread_pid(struct machine *machine,
goto out_err;

if (thread__maps(th) == thread__maps(leader))
- return;
+ goto out_put;

if (thread__maps(th)) {
/*
@@ -579,7 +579,7 @@ __threads__get_last_match(struct threads *threads, struct machine *machine,
machine__update_thread_pid(machine, th, pid);
return thread__get(th);
}
-
+ thread__put(threads->last_match);
threads->last_match = NULL;
}

@@ -601,7 +601,8 @@ threads__get_last_match(struct threads *threads, struct machine *machine,
static void
__threads__set_last_match(struct threads *threads, struct thread *th)
{
- threads->last_match = th;
+ thread__put(threads->last_match);
+ threads->last_match = thread__get(th);
}

static void
@@ -664,7 +665,6 @@ static struct thread *____machine__findnew_thread(struct machine *machine,

rb_link_node(&nd->rb_node, parent, p);
rb_insert_color_cached(&nd->rb_node, &threads->entries, leftmost);
-
/*
* We have to initialize maps separately after rb tree is updated.
*
@@ -673,6 +673,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
* the rb tree.
*/
if (thread__init_maps(th, machine)) {
+ pr_err("Thread init failed thread %d\n", pid);
rb_erase_cached(&nd->rb_node, &threads->entries);
RB_CLEAR_NODE(&nd->rb_node);
free(nd);
@@ -682,11 +683,10 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
/*
* It is now in the rbtree, get a ref
*/
- thread__get(th);
threads__set_last_match(threads, th);
++threads->nr;

- return th;
+ return thread__get(th);
}

struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
@@ -2395,6 +2395,8 @@ static int add_callchain_ip(struct thread *thread,
iter_cycles, branch_from, srcline);
out:
addr_location__exit(&al);
+ maps__put(ms.maps);
+ map__put(ms.map);
return err;
}

--
2.41.0.rc0.172.g3f132b7071-goog