Received-SPF: pass (google.com: domain of linux-kernel+bounces-184329-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Date: Mon, 20 May 2024 20:57:37 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: LKML <linux-kernel@vger.kernel.org>, Linux Trace Kernel
 <linux-trace-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@efficios.com>, Shuah Khan <shuah@kernel.org>,
 linux-kselftest@vger.kernel.org
Subject: [PATCH] tracing/selftests: Fix kprobe event name test for .isra.
 functions
Message-ID: <20240520205737.5085e53a@gandalf.local.home>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

The kprobe_eventname.tc test checks if a function with .isra. can have a
kprobe attached to it. It loops through the kallsyms file for all the
functions that have the .isra. name, and checks if it exists in the
available_filter_functions file, and if it does, it uses it to attach a
kprobe to it.

The issue is that kprobes can not attach to functions that are listed more
than once in available_filter_functions. With the latest kernel, the
function that is found is: rapl_event_update.isra.0

  # grep rapl_event_update.isra.0 /sys/kernel/tracing/available_filter_functions
  rapl_event_update.isra.0
  rapl_event_update.isra.0

It is listed twice. This causes the attached kprobe to it to fail which in
turn fails the test. Instead of just picking the function function that is
found in available_filter_functions, pick the first one that is listed
only once in available_filter_functions.

Cc: stable@vger.kernel.org
Fixes: 604e3548236de ("selftests/ftrace: Select an existing function in kprobe_eventname test")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 .../testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
index 1f6981ef7afa..ba19b81cef39 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
@@ -30,7 +30,8 @@ find_dot_func() {
 	fi
 
 	grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
-		if grep -s $f available_filter_functions; then
+		cnt=`grep -s $f available_filter_functions | wc -l`;
+		if [ $cnt -eq 1 ]; then
 			echo $f
 			break
 		fi
-- 
2.43.0