[PATCH] printk: Export console trace point for kcsan/kasan/kfence/kmsan

[PATCH] printk: Export console trace point for kcsan/kasan/kfence/kmsan

[Pavankumar Kondeti]

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.

Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
---
 kernel/kcsan/kcsan_test.c | 20 ++++++--------------
 kernel/printk/printk.c    |  2 ++
 mm/kasan/kasan_test.c     | 22 ++--------------------
 mm/kfence/kfence_test.c   | 22 ++--------------------
 mm/kmsan/kmsan_test.c     | 22 ++--------------------
 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 a5ed2e53547c..8bb9e8752d65 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 74cd80c12b25..edf3158fc075 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 088e21a48dc4..06e18f76c641 100644
--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -541,33 +541,15 @@ 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();
 }
 
-- 
2.25.1

Re: [PATCH] printk: Export console trace point for kcsan/kasan/kfence/kmsan

[Petr Mladek]

On Thu 2023-04-13 15:38:59, Pavankumar Kondeti wrote:
> 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.
> 
> Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>

Makes sense. From the printk side:

Acked-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr

Re: [PATCH] printk: Export console trace point for kcsan/kasan/kfence/kmsan

[Sergey Senozhatsky]

On (23/04/13 15:38), Pavankumar Kondeti wrote:
> 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.
> 
> Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> # printk

Re: [PATCH] printk: Export console trace point for kcsan/kasan/kfence/kmsan

[Alexander Potapenko]

On Sat, Apr 15, 2023 at 8:58 AM Sergey Senozhatsky
<senozhatsky@chromium.org> wrote:
>
> On (23/04/13 15:38), Pavankumar Kondeti wrote:
> > 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.
> >
> > Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> # printk
Reviewed-by: Alexander Potapenko <glider@google.com>