[PATCH v2] tracing: Remove bogus 64-bit synth_event_trace() vararg assumption

[Tom Zanussi]

The vararg code in synth_event_trace() assumed the args were 64 bit
which is not the case on 32-bit systems.  Just use long which should
work on every system.

Also remove all the u64 casts from the synth event test module, which
also cause compile warnings on 32-bit compiles.

This fixes the bug reported by the kernel test robot/Rong Chen as
reported here:

20200212113444.GS12867@shao2-debian/">https://lore.kernel.org/lkml/20200212113444.GS12867@shao2-debian/

With this commit, the lkp-tests tests now pass, as do the synth/kprobe
event test modules and selftests on x86_64.

Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
 kernel/trace/synth_event_gen_test.c | 24 ++++++++++++------------
 kernel/trace/trace_events_hist.c    |  6 +++---
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c
index 4aefe003cb7c..f0e14106048c 100644
--- a/kernel/trace/synth_event_gen_test.c
+++ b/kernel/trace/synth_event_gen_test.c
@@ -111,11 +111,11 @@ static int __init test_gen_synth_cmd(void)
 	/* Create some bogus values just for testing */
 
 	vals[0] = 777;			/* next_pid_field */
-	vals[1] = (u64)"hula hoops";	/* next_comm_field */
+	vals[1] = (long)"hula hoops";	/* next_comm_field */
 	vals[2] = 1000000;		/* ts_ns */
 	vals[3] = 1000;			/* ts_ms */
 	vals[4] = smp_processor_id();	/* cpu */
-	vals[5] = (u64)"thneed";	/* my_string_field */
+	vals[5] = (long)"thneed";	/* my_string_field */
 	vals[6] = 598;			/* my_int_field */
 
 	/* Now generate a gen_synth_test event */
@@ -218,11 +218,11 @@ static int __init test_empty_synth_event(void)
 	/* Create some bogus values just for testing */
 
 	vals[0] = 777;			/* next_pid_field */
-	vals[1] = (u64)"tiddlywinks";	/* next_comm_field */
+	vals[1] = (long)"tiddlywinks";	/* next_comm_field */
 	vals[2] = 1000000;		/* ts_ns */
 	vals[3] = 1000;			/* ts_ms */
 	vals[4] = smp_processor_id();	/* cpu */
-	vals[5] = (u64)"thneed_2.0";	/* my_string_field */
+	vals[5] = (long)"thneed_2.0";	/* my_string_field */
 	vals[6] = 399;			/* my_int_field */
 
 	/* Now trace an empty_synth_test event */
@@ -290,11 +290,11 @@ static int __init test_create_synth_event(void)
 	/* Create some bogus values just for testing */
 
 	vals[0] = 777;			/* next_pid_field */
-	vals[1] = (u64)"tiddlywinks";	/* next_comm_field */
+	vals[1] = (long)"tiddlywinks";	/* next_comm_field */
 	vals[2] = 1000000;		/* ts_ns */
 	vals[3] = 1000;			/* ts_ms */
 	vals[4] = smp_processor_id();	/* cpu */
-	vals[5] = (u64)"thneed";	/* my_string_field */
+	vals[5] = (long)"thneed";	/* my_string_field */
 	vals[6] = 398;			/* my_int_field */
 
 	/* Now generate a create_synth_test event */
@@ -330,7 +330,7 @@ static int __init test_add_next_synth_val(void)
 		goto out;
 
 	/* next_comm_field */
-	ret = synth_event_add_next_val((u64)"slinky", &trace_state);
+	ret = synth_event_add_next_val((long)"slinky", &trace_state);
 	if (ret)
 		goto out;
 
@@ -350,7 +350,7 @@ static int __init test_add_next_synth_val(void)
 		goto out;
 
 	/* my_string_field */
-	ret = synth_event_add_next_val((u64)"thneed_2.01", &trace_state);
+	ret = synth_event_add_next_val((long)"thneed_2.01", &trace_state);
 	if (ret)
 		goto out;
 
@@ -396,12 +396,12 @@ static int __init test_add_synth_val(void)
 	if (ret)
 		goto out;
 
-	ret = synth_event_add_val("next_comm_field", (u64)"silly putty",
+	ret = synth_event_add_val("next_comm_field", (long)"silly putty",
 				  &trace_state);
 	if (ret)
 		goto out;
 
-	ret = synth_event_add_val("my_string_field", (u64)"thneed_9",
+	ret = synth_event_add_val("my_string_field", (long)"thneed_9",
 				  &trace_state);
 	if (ret)
 		goto out;
@@ -424,11 +424,11 @@ static int __init test_trace_synth_event(void)
 	/* Trace some bogus values just for testing */
 	ret = synth_event_trace(create_synth_test, 7,	/* number of values */
 				444,			/* next_pid_field */
-				(u64)"clackers",	/* next_comm_field */
+				"clackers",		/* next_comm_field */
 				1000000,		/* ts_ns */
 				1000,			/* ts_ms */
 				smp_processor_id(),	/* cpu */
-				(u64)"Thneed",		/* my_string_field */
+				"Thneed",		/* my_string_field */
 				999);			/* my_int_field */
 	return ret;
 }
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 483b3fd1094f..b8dd28f546d8 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1887,12 +1887,12 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
 
 	va_start(args, n_vals);
 	for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
-		u64 val;
+		long val;
 
-		val = va_arg(args, u64);
+		val = va_arg(args, long);
 
 		if (state.event->fields[i]->is_string) {
-			char *str_val = (char *)(long)val;
+			char *str_val = (char *)val;
 			char *str_field = (char *)&state.entry->fields[n_u64];
 
 			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
-- 
2.14.1