perf callchain: Use pthread keys for tls callchain_cursor

Pthread keys are more portable than __thread and allow the association
of a destructor with the key. Use the destructor to clean up TLS
callchain cursors to aid understanding memory leaks.

Committer notes:

Had to fixup a series of unconverted places and also check for the
return of get_tls_callchain_cursor() as it may fail and return NULL.

In that unlikely case we now either print something to a file, if the
caller was expecting to print a callchain, or return an error code to
state that resolving the callchain isn't possible.

In some cases this was made easier because thread__resolve_callchain()
already can fail for other reasons, so this new one (cursor == NULL) can
be added and the callers don't have to explicitely check for this new
condition.

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/20230608232823.4027869-25-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/builtin-trace.c b/tools/perf/builtin-trace.c
index 6a1e75f06832..6e73d0e95715 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2437,7 +2437,7 @@ static int trace__fprintf_callchain(struct trace *trace, struct perf_sample *sam
 				        EVSEL__PRINT_DSO |
 				        EVSEL__PRINT_UNKNOWN_AS_ADDR;
 
-	return sample__fprintf_callchain(sample, 38, print_opts, &callchain_cursor, symbol_conf.bt_stop_list, trace->output);
+	return sample__fprintf_callchain(sample, 38, print_opts, get_tls_callchain_cursor(), symbol_conf.bt_stop_list, trace->output);
 }
 
 static const char *errno_to_name(struct evsel *evsel, int err)
@@ -2491,9 +2491,11 @@ static int trace__sys_exit(struct trace *trace, struct evsel *evsel,
 		goto out;
 
 	if (sample->callchain) {
-		callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
+		struct callchain_cursor *cursor = get_tls_callchain_cursor();
+
+		callchain_ret = trace__resolve_callchain(trace, evsel, sample, cursor);
 		if (callchain_ret == 0) {
-			if (callchain_cursor.nr < trace->min_stack)
+			if (cursor->nr < trace->min_stack)
 				goto out;
 			callchain_ret = 1;
 		}
@@ -2795,9 +2797,11 @@ static int trace__event_handler(struct trace *trace, struct evsel *evsel,
 	thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
 
 	if (sample->callchain) {
-		callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
+		struct callchain_cursor *cursor = get_tls_callchain_cursor();
+
+		callchain_ret = trace__resolve_callchain(trace, evsel, sample, cursor);
 		if (callchain_ret == 0) {
-			if (callchain_cursor.nr < trace->min_stack)
+			if (cursor->nr < trace->min_stack)
 				goto out;
 			callchain_ret = 1;
 		}
@@ -2899,9 +2903,11 @@ static int trace__pgfault(struct trace *trace,
 	thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
 
 	if (sample->callchain) {
-		callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
+		struct callchain_cursor *cursor = get_tls_callchain_cursor();
+
+		callchain_ret = trace__resolve_callchain(trace, evsel, sample, cursor);
 		if (callchain_ret == 0) {
-			if (callchain_cursor.nr < trace->min_stack)
+			if (cursor->nr < trace->min_stack)
 				goto out_put;
 			callchain_ret = 1;
 		}