[PATCH 2/2] perf trace: Fix segfault on perf trace -i perf.data

[Namhyung Kim <namhyung@kernel.org>]

From: Namhyung Kim <namhyung.kim@lge.com>

When replaying a previous record session, it'll get a segfault since
it doesn't initialize evsel->priv for finding syscall id.  So fix it
by initialize sys_enter/exit evsel manually.

While at it, factor out perf_evsel__init_syscall_tp() to init a
syscall evsel and remove unused perf_session__has_tp().

Cc: David Ahern <dsahern@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-trace.c | 63 ++++++++++++++++++++++++++++------------------
 1 file changed, 38 insertions(+), 25 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index aeb6296a76bd..6a18ed0a3e2a 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -149,20 +149,28 @@ static void perf_evsel__delete_priv(struct perf_evsel *evsel)
 	perf_evsel__delete(evsel);
 }
 
-static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction, void *handler)
+static int perf_evsel__init_syscall_tp(struct perf_evsel *evsel, void *handler)
 {
-	struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction);
+	evsel->priv = malloc(sizeof(struct syscall_tp));
 
-	if (evsel) {
-		evsel->priv = malloc(sizeof(struct syscall_tp));
+	if (evsel->priv == NULL)
+		return -ENOMEM;
 
-		if (evsel->priv == NULL)
-			goto out_delete;
+	if (perf_evsel__init_sc_tp_uint_field(evsel, id))
+		return -1;
 
-		if (perf_evsel__init_sc_tp_uint_field(evsel, id))
-			goto out_delete;
+	evsel->handler = handler;
+	return 0;
+}
+
+static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction,
+						    void *handler)
+{
+	struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction);
 
-		evsel->handler = handler;
+	if (evsel) {
+		if (perf_evsel__init_syscall_tp(evsel, handler) < 0)
+			goto out_delete;
 	}
 
 	return evsel;
@@ -1754,16 +1762,6 @@ static int trace__process_sample(struct perf_tool *tool,
 	return err;
 }
 
-static bool
-perf_session__has_tp(struct perf_session *session, const char *name)
-{
-	struct perf_evsel *evsel;
-
-	evsel = perf_evlist__find_tracepoint_by_name(session->evlist, name);
-
-	return evsel != NULL;
-}
-
 static int parse_target_str(struct trace *trace)
 {
 	if (trace->opts.target.pid) {
@@ -2000,8 +1998,6 @@ out_error:
 static int trace__replay(struct trace *trace)
 {
 	const struct perf_evsel_str_handler handlers[] = {
-		{ "raw_syscalls:sys_enter",  trace__sys_enter, },
-		{ "raw_syscalls:sys_exit",   trace__sys_exit, },
 		{ "probe:vfs_getname",	     trace__vfs_getname, },
 	};
 	struct perf_data_file file = {
@@ -2009,6 +2005,7 @@ static int trace__replay(struct trace *trace)
 		.mode  = PERF_DATA_MODE_READ,
 	};
 	struct perf_session *session;
+	struct perf_evsel *evsel;
 	int err = -1;
 
 	trace->tool.sample	  = trace__process_sample;
@@ -2040,13 +2037,29 @@ static int trace__replay(struct trace *trace)
 	if (err)
 		goto out;
 
-	if (!perf_session__has_tp(session, "raw_syscalls:sys_enter")) {
-		pr_err("Data file does not have raw_syscalls:sys_enter events\n");
+	evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
+						     "raw_syscalls:sys_enter");
+	if (evsel == NULL) {
+		pr_err("Data file does not have raw_syscalls:sys_enter event\n");
+		goto out;
+	}
+
+	if (perf_evsel__init_syscall_tp(evsel, trace__sys_enter) < 0 ||
+	    perf_evsel__init_sc_tp_ptr_field(evsel, args)) {
+		pr_err("Error during initialize raw_syscalls:sys_enter event\n");
+		goto out;
+	}
+
+	evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
+						     "raw_syscalls:sys_exit");
+	if (evsel == NULL) {
+		pr_err("Data file does not have raw_syscalls:sys_exit event\n");
 		goto out;
 	}
 
-	if (!perf_session__has_tp(session, "raw_syscalls:sys_exit")) {
-		pr_err("Data file does not have raw_syscalls:sys_exit events\n");
+	if (perf_evsel__init_syscall_tp(evsel, trace__sys_exit) < 0 ||
+	    perf_evsel__init_sc_tp_uint_field(evsel, ret)) {
+		pr_err("Error during initialize raw_syscalls:sys_exit event\n");
 		goto out;
 	}
 
-- 
1.7.11.7