On Wed, 21 Aug 2024 15:09:03 -0400 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > From: Steven Rostedt <rostedt@xxxxxxxxxxx> > > 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 This looks good to me, but note that this depends on the above fix, unless that, this may crash the kernel. I think the above fix should be merged in v6.11-rcX so this may be safe for released kernel. Thanks, > > Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> > --- > .../ftrace/test.d/ftrace/fgraph-profiler.tc | 30 +++++++++++++++++++ > 1 file changed, 30 insertions(+) > create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc > > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc > new file mode 100644 > index 000000000000..62d44a1395da > --- /dev/null > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-profiler.tc > @@ -0,0 +1,30 @@ > +#!/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 function_graph and profiling to 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 > + > +sleep 1 > + > +exit 0 > -- > 2.43.0 > -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
