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From: Jiri Olsa <jolsa@redhat.com>
To: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH 4/8] tracing: Add trampoline/graph selftest
Date: Tue, 31 Aug 2021 11:50:13 +0200	[thread overview]
Message-ID: <20210831095017.412311-5-jolsa@kernel.org> (raw)
In-Reply-To: <20210831095017.412311-1-jolsa@kernel.org>

Adding selftest for checking that direct trampoline can
co-exist together with graph tracer on same function.

This is supported for CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
config option, which is defined only for x86_64 for now.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 kernel/trace/trace_selftest.c | 49 ++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index adf7ef194005..f8e55b949cdd 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -750,6 +750,8 @@ static struct fgraph_ops fgraph_ops __initdata  = {
 	.retfunc		= &trace_graph_return,
 };
 
+noinline __noclone static void trace_direct_tramp(void) { }
+
 /*
  * Pretty much the same than for the function tracer from which the selftest
  * has been borrowed.
@@ -760,6 +762,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 {
 	int ret;
 	unsigned long count;
+	char *func_name __maybe_unused;
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 	if (ftrace_filter_param) {
@@ -808,8 +811,52 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 		goto out;
 	}
 
-	/* Don't test dynamic tracing, the function tracer already did */
+#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
+	tracing_reset_online_cpus(&tr->array_buffer);
+	set_graph_array(tr);
 
+	/*
+	 * Some archs *cough*PowerPC*cough* add characters to the
+	 * start of the function names. We simply put a '*' to
+	 * accommodate them.
+	 */
+	func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
+	ftrace_set_global_filter(func_name, strlen(func_name), 1);
+
+	/*
+	 * 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);
+	if (ret)
+		goto out;
+
+	ret = register_ftrace_graph(&fgraph_ops);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
+
+	DYN_FTRACE_TEST_NAME();
+
+	count = 0;
+
+	tracing_stop();
+	/* check the trace buffer */
+	ret = trace_test_buffer(&tr->array_buffer, &count);
+
+	unregister_ftrace_graph(&fgraph_ops);
+
+	tracing_start();
+
+	if (!ret && !count) {
+		ret = -1;
+		goto out;
+	}
+#endif
+
+	/* Don't test dynamic tracing, the function tracer already did */
 out:
 	/* Stop it if we failed */
 	if (ret)
-- 
2.31.1


  parent reply	other threads:[~2021-08-31  9:52 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31  9:50 [PATCH 0/8] x86/ftrace: Add direct batch interface Jiri Olsa
2021-08-31  9:50 ` [PATCH 1/8] x86/ftrace: Remove extra orig rax move Jiri Olsa
2021-08-31  9:50 ` [PATCH 2/8] x86/ftrace: Remove fault protection code in prepare_ftrace_return Jiri Olsa
2021-08-31  9:50 ` [PATCH 3/8] x86/ftrace: Make function graph use ftrace directly Jiri Olsa
2021-08-31  9:50 ` Jiri Olsa [this message]
2021-08-31  9:50 ` [PATCH 5/8] ftrace: Add ftrace_add_rec_direct function Jiri Olsa
2021-08-31  9:50 ` [PATCH 6/8] ftrace: Add multi direct register/unregister interface Jiri Olsa
2021-09-14 21:35   ` Steven Rostedt
2021-09-16 19:45     ` Jiri Olsa
2021-08-31  9:50 ` [PATCH 7/8] ftrace: Add multi direct modify interface Jiri Olsa
2021-09-14 21:41   ` Steven Rostedt
2021-09-15 21:47     ` Steven Rostedt
2021-09-16 19:49       ` Jiri Olsa
2021-09-16 20:41         ` Steven Rostedt
2021-08-31  9:50 ` [PATCH 8/8] ftrace/samples: Add multi direct interface test module Jiri Olsa
2021-09-01 15:23 ` [PATCH 0/8] x86/ftrace: Add direct batch interface Alexei Starovoitov
2021-09-01 19:06   ` Jiri Olsa
2021-09-02 14:54     ` Steven Rostedt
2021-10-08  9:13 [PATCHv2 " Jiri Olsa
2021-10-08  9:13 ` [PATCH 4/8] tracing: Add trampoline/graph selftest Jiri Olsa

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