Commit 4ee5ca9a authored by Steven Rostedt's avatar Steven Rostedt Committed by Shuah Khan
Browse files

ftrace/selftest: Test combination of function_graph tracer and function profiler 

Masami reported a bug when running function graph tracing then the
function profiler. The following commands would cause a kernel crash:

  # cd /sys/kernel/tracing/
  # echo function_graph > current_tracer
  # echo 1 > function_profile_enabled

In that order. Create a test to test this two to make sure this does not
come back as a regression.

Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2

Link: https://lore.kernel.org/all/20241010165235.35122877@gandalf.local.home/


Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent a0cc6493

tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc

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#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: ftrace - function profiler with function graph tracing

# requires: function_profile_enabled set_ftrace_filter function_graph:tracer



# The function graph tracer can now be run along side of the function

# profiler. But there was a bug that caused the combination of the two

# to crash. It also required the function graph tracer to be started

# first.

#

# This test triggers that bug

#

# We need both function_graph and profiling to run this test



fail() { # mesg

    echo $1

    exit_fail

}



echo "Enabling function graph tracer:"

echo function_graph > current_tracer

echo "enable profiler"



# Older kernels do not allow function_profile to be enabled with

# function graph tracer. If the below fails, mark it as unsupported

echo 1 > function_profile_enabled || exit_unsupported



# Let it run for a bit to make sure nothing explodes

sleep 1



exit 0