From:   Florent Revest <revest@chromium.org>
To:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org
Cc:     catalin.marinas@arm.com, will@kernel.org, rostedt@goodmis.org,
        mhiramat@kernel.org, mark.rutland@arm.com, ast@kernel.org,
        daniel@iogearbox.net, andrii@kernel.org, kpsingh@kernel.org,
        jolsa@kernel.org, xukuohai@huaweicloud.com,
        Florent Revest <revest@chromium.org>
Subject: [PATCH 1/8] ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multi
Date:   Wed,  1 Feb 2023 17:34:13 +0100
Message-Id: <20230201163420.1579014-2-revest@chromium.org>
In-Reply-To: <20230201163420.1579014-1-revest@chromium.org>
References: <20230201163420.1579014-1-revest@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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