[PATCH 1/8] ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multi

Florent Revest
2023-02-01T16:36:30Z

The _multi API requires that users keep their own ops and can enforce
that an op is only associated to one direct call.

Signed-off-by: Florent Revest <revest@chromium.org>
---
kernel/trace/trace_selftest.c | 9 ++++++---
samples/ftrace/ftrace-direct-modify.c | 11 +++++++----
samples/ftrace/ftrace-direct-too.c | 12 +++++++-----
samples/ftrace/ftrace-direct.c | 12 +++++++-----
4 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index ff0536cea968..9b7f10cbc51d 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -806,6 +806,9 @@ trace_selftest_startup_function_graph(struct tracer *trace,
int ret;
unsigned long count;
char *func_name __maybe_unused;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ struct ftrace_ops direct = {};
+#endif

#ifdef CONFIG_DYNAMIC_FTRACE
if (ftrace_filter_param) {
@@ -870,8 +873,8 @@ trace_selftest_startup_function_graph(struct tracer *trace,
* Register direct function together with graph tracer
* and make sure we get graph trace.
*/
- ret = register_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME,
- (unsigned long) trace_direct_tramp);
+ ftrace_set_filter_ip(&direct, (unsigned long)DYN_FTRACE_TEST_NAME, 0, 0);
+ ret = register_ftrace_direct_multi(&direct, (unsigned long)trace_direct_tramp);
if (ret)
goto out;

@@ -891,7 +894,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,

unregister_ftrace_graph(&fgraph_ops);

- ret = unregister_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME,
+ ret = unregister_ftrace_direct_multi(&direct,
(unsigned long) trace_direct_tramp);
if (ret)
goto out;
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index de5a0f67f320..e1e6c286970c 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -96,6 +96,8 @@ asm (

#endif /* CONFIG_S390 */

+static struct ftrace_ops direct;
+
static unsigned long my_tramp = (unsigned long)my_tramp1;
static unsigned long tramps[2] = {
(unsigned long)my_tramp1,
@@ -114,7 +116,7 @@ static int simple_thread(void *arg)
if (ret)
continue;
t ^= 1;
- ret = modify_ftrace_direct(my_ip, my_tramp, tramps[t]);
+ ret = modify_ftrace_direct_multi(&direct, tramps[t]);
if (!ret)
my_tramp = tramps[t];
WARN_ON_ONCE(ret);
@@ -129,7 +131,8 @@ static int __init ftrace_direct_init(void)
{
int ret;

- ret = register_ftrace_direct(my_ip, my_tramp);
+ ftrace_set_filter_ip(&direct, (unsigned long) my_ip, 0, 0);
+ ret = register_ftrace_direct_multi(&direct, my_tramp);
if (!ret)
simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn");
return ret;
@@ -138,12 +141,12 @@ static int __init ftrace_direct_init(void)
static void __exit ftrace_direct_exit(void)
{
kthread_stop(simple_tsk);
- unregister_ftrace_direct(my_ip, my_tramp);
+ unregister_ftrace_direct_multi(&direct, my_tramp);
}

module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);

MODULE_AUTHOR("Steven Rostedt");
-MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct()");
+MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct_multi()");
MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index e13fb59a2b47..0e907092e2c0 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -70,21 +70,23 @@ asm (

#endif /* CONFIG_S390 */

+static struct ftrace_ops direct;
+
static int __init ftrace_direct_init(void)
{
- return register_ftrace_direct((unsigned long)handle_mm_fault,
- (unsigned long)my_tramp);
+ ftrace_set_filter_ip(&direct, (unsigned long) handle_mm_fault, 0, 0);
+
+ return register_ftrace_direct_multi(&direct, (unsigned long) my_tramp);
}

static void __exit ftrace_direct_exit(void)
{
- unregister_ftrace_direct((unsigned long)handle_mm_fault,
- (unsigned long)my_tramp);
+ unregister_ftrace_direct_multi(&direct, (unsigned long)my_tramp);
}

module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);

MODULE_AUTHOR("Steven Rostedt");
-MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
+MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct_multi()");
MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 1f769d0db20f..e446c38f6b58 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -63,21 +63,23 @@ asm (

#endif /* CONFIG_S390 */

+static struct ftrace_ops direct;
+
static int __init ftrace_direct_init(void)
{
- return register_ftrace_direct((unsigned long)wake_up_process,
- (unsigned long)my_tramp);
+ ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0);
+
+ return register_ftrace_direct_multi(&direct, (unsigned long) my_tramp);
}

static void __exit ftrace_direct_exit(void)
{
- unregister_ftrace_direct((unsigned long)wake_up_process,
- (unsigned long)my_tramp);
+ unregister_ftrace_direct_multi(&direct, (unsigned long)my_tramp);
}

module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);

MODULE_AUTHOR("Steven Rostedt");
-MODULE_DESCRIPTION("Example use case of using register_ftrace_direct()");
+MODULE_DESCRIPTION("Example use case of using register_ftrace_direct_multi()");
MODULE_LICENSE("GPL");
--
2.39.1.519.gcb327c4b5f-goog