printk: export console trace point for kcsan/kasan/kfence/kmsan

The console tracepoint is used by kcsan/kasan/kfence/kmsan test modules. 
Since this tracepoint is not exported, these modules iterate over all
available tracepoints to find the console trace point.  Export the trace
point so that it can be directly used.

Link: https://lkml.kernel.org/r/20230413100859.1492323-1-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Marco Elver <elver@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

5 files changed, 14 insertions, 74 deletions

diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
index a60c561724be..0ddbdab5903d 100644
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -1572,34 +1572,26 @@ static void test_exit(struct kunit *test)
 }
 
 __no_kcsan
-static void register_tracepoints(struct tracepoint *tp, void *ignore)
+static void register_tracepoints(void)
 {
-	check_trace_callback_type_console(probe_console);
-	if (!strcmp(tp->name, "console"))
-		WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
+	register_trace_console(probe_console, NULL);
 }
 
 __no_kcsan
-static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
+static void unregister_tracepoints(void)
 {
-	if (!strcmp(tp->name, "console"))
-		tracepoint_probe_unregister(tp, probe_console, NULL);
+	unregister_trace_console(probe_console, NULL);
 }
 
 static int kcsan_suite_init(struct kunit_suite *suite)
 {
-	/*
-	 * Because we want to be able to build the test as a module, we need to
-	 * iterate through all known tracepoints, since the static registration
-	 * won't work here.
-	 */
-	for_each_kernel_tracepoint(register_tracepoints, NULL);
+	register_tracepoints();
 	return 0;
 }
 
 static void kcsan_suite_exit(struct kunit_suite *suite)
 {
-	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+	unregister_tracepoints();
 	tracepoint_synchronize_unregister();
 }
 
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index fd0c9f913940..1c71bb170e85 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -71,6 +71,8 @@ EXPORT_SYMBOL_GPL(console_printk);
 atomic_t ignore_console_lock_warning __read_mostly = ATOMIC_INIT(0);
 EXPORT_SYMBOL(ignore_console_lock_warning);
 
+EXPORT_TRACEPOINT_SYMBOL_GPL(console);
+
 /*
  * Low level drivers may need that to know if they can schedule in
  * their unblank() callback or not. So let's export it.
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index a375776f9896..b61cc6a42541 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -56,19 +56,6 @@ static void probe_console(void *ignore, const char *buf, size_t len)
 		WRITE_ONCE(test_status.async_fault, true);
 }
 
-static void register_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	check_trace_callback_type_console(probe_console);
-	if (!strcmp(tp->name, "console"))
-		WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
-}
-
-static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	if (!strcmp(tp->name, "console"))
-		tracepoint_probe_unregister(tp, probe_console, NULL);
-}
-
 static int kasan_suite_init(struct kunit_suite *suite)
 {
 	if (!kasan_enabled()) {
@@ -86,12 +73,7 @@ static int kasan_suite_init(struct kunit_suite *suite)
 	 */
 	multishot = kasan_save_enable_multi_shot();
 
-	/*
-	 * Because we want to be able to build the test as a module, we need to
-	 * iterate through all known tracepoints, since the static registration
-	 * won't work here.
-	 */
-	for_each_kernel_tracepoint(register_tracepoints, NULL);
+	register_trace_console(probe_console, NULL);
 	return 0;
 }
 
@@ -99,7 +81,7 @@ static void kasan_suite_exit(struct kunit_suite *suite)
 {
 	kasan_kunit_test_suite_end();
 	kasan_restore_multi_shot(multishot);
-	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+	unregister_trace_console(probe_console, NULL);
 	tracepoint_synchronize_unregister();
 }
 
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index b5d66a69200d..6aee19a79236 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -825,33 +825,15 @@ static void test_exit(struct kunit *test)
 	test_cache_destroy();
 }
 
-static void register_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	check_trace_callback_type_console(probe_console);
-	if (!strcmp(tp->name, "console"))
-		WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
-}
-
-static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	if (!strcmp(tp->name, "console"))
-		tracepoint_probe_unregister(tp, probe_console, NULL);
-}
-
 static int kfence_suite_init(struct kunit_suite *suite)
 {
-	/*
-	 * Because we want to be able to build the test as a module, we need to
-	 * iterate through all known tracepoints, since the static registration
-	 * won't work here.
-	 */
-	for_each_kernel_tracepoint(register_tracepoints, NULL);
+	register_trace_console(probe_console, NULL);
 	return 0;
 }
 
 static void kfence_suite_exit(struct kunit_suite *suite)
 {
-	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+	unregister_trace_console(probe_console, NULL);
 	tracepoint_synchronize_unregister();
 }
 
diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c
index d9eb141c27aa..312989aa2865 100644
--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -626,33 +626,15 @@ static void test_exit(struct kunit *test)
 {
 }
 
-static void register_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	check_trace_callback_type_console(probe_console);
-	if (!strcmp(tp->name, "console"))
-		WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
-}
-
-static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
-{
-	if (!strcmp(tp->name, "console"))
-		tracepoint_probe_unregister(tp, probe_console, NULL);
-}
-
 static int kmsan_suite_init(struct kunit_suite *suite)
 {
-	/*
-	 * Because we want to be able to build the test as a module, we need to
-	 * iterate through all known tracepoints, since the static registration
-	 * won't work here.
-	 */
-	for_each_kernel_tracepoint(register_tracepoints, NULL);
+	register_trace_console(probe_console, NULL);
 	return 0;
 }
 
 static void kmsan_suite_exit(struct kunit_suite *suite)
 {
-	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+	unregister_trace_console(probe_console, NULL);
 	tracepoint_synchronize_unregister();
 }