Re: [PATCH v6 4/4] selftests/ftrace: Add accept cases for fprobe list syntax

Masami Hiramatsu
2026-03-24T04:12:07Z

On Thu, 5 Feb 2026 08:58:42 -0500
"Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote:

> Add fprobe_list.tc to test the comma-separated symbol list syntax
> with :entry/:exit suffixes. Three scenarios are covered:
>
> 1. List with default (entry) behavior and ! exclusion
> 2. List with explicit :entry suffix
> 3. List with :exit suffix for return probes

Could you also add wildcard pattern test?

>
> Each test verifies that the correct functions appear in
> enabled_functions and that excluded (!) symbols are absent.
>
> Note: The existing tests add_remove_fprobe.tc, fprobe_syntax_errors.tc,
> and add_remove_fprobe_repeat.tc check their "requires" line against the
> tracefs README for the old "%return" syntax pattern. Since the README
> now documents ":entry|:exit" instead, these tests report UNSUPPORTED.
> Their "requires" lines need updating in a follow-up patch.

This means you'll break the selftest. please fix those test first.
(This fix must be done before "tracing/fprobe: Support comma-separated
symbols and :entry/:exit" so that we can safely bisect it.)

Thank you,

>
> Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
> ---
> .../ftrace/test.d/dynevent/fprobe_list.tc | 92 +++++++++++++++++++
> 1 file changed, 92 insertions(+)
> create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
>
> diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
> new file mode 100644
> index 000000000000..45e57c6f487d
> --- /dev/null
> +++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
> @@ -0,0 +1,92 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# description: Fprobe event list syntax and :entry/:exit suffixes
> +# requires: dynamic_events "f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]":README
> +
> +# Setup symbols to test. These are common kernel functions.
> +PLACE=vfs_read
> +PLACE2=vfs_write
> +PLACE3=vfs_open
> +
> +echo 0 > events/enable
> +echo > dynamic_events
> +
> +# Get baseline count of enabled functions (should be 0 if clean, but be safe)
> +if [ -f enabled_functions ]; then
> + ocnt=`cat enabled_functions | wc -l`
> +else
> + ocnt=0
> +fi
> +
> +# Test 1: List default (entry) with exclusion
> +# Target: Trace vfs_read and vfs_open, but EXCLUDE vfs_write
> +echo "f:test/list_entry $PLACE,!$PLACE2,$PLACE3" >> dynamic_events
> +grep -q "test/list_entry" dynamic_events
> +test -d events/test/list_entry
> +
> +echo 1 > events/test/list_entry/enable
> +
> +grep -q "$PLACE" enabled_functions
> +grep -q "$PLACE3" enabled_functions
> +! grep -q "$PLACE2" enabled_functions
> +
> +# Check count (Baseline + 2 new functions)
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne $((ocnt + 2)) ]; then
> + exit_fail
> +fi
> +
> +# Cleanup Test 1
> +echo 0 > events/test/list_entry/enable
> +echo "-:test/list_entry" >> dynamic_events
> +! grep -q "test/list_entry" dynamic_events
> +
> +# Count should return to baseline
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne $ocnt ]; then
> + exit_fail
> +fi
> +
> +# Test 2: List with explicit :entry suffix
> +# (Should behave exactly like Test 1)
> +echo "f:test/list_entry_exp $PLACE,!$PLACE2,$PLACE3:entry" >> dynamic_events
> +grep -q "test/list_entry_exp" dynamic_events
> +test -d events/test/list_entry_exp
> +
> +echo 1 > events/test/list_entry_exp/enable
> +
> +grep -q "$PLACE" enabled_functions
> +grep -q "$PLACE3" enabled_functions
> +! grep -q "$PLACE2" enabled_functions
> +
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne $((ocnt + 2)) ]; then
> + exit_fail
> +fi
> +
> +# Cleanup Test 2
> +echo 0 > events/test/list_entry_exp/enable
> +echo "-:test/list_entry_exp" >> dynamic_events
> +
> +# Test 3: List with :exit suffix
> +echo "f:test/list_exit $PLACE,!$PLACE2,$PLACE3:exit" >> dynamic_events
> +grep -q "test/list_exit" dynamic_events
> +test -d events/test/list_exit
> +
> +echo 1 > events/test/list_exit/enable
> +
> +# Even for return probes, enabled_functions lists the attached symbols
> +grep -q "$PLACE" enabled_functions
> +grep -q "$PLACE3" enabled_functions
> +! grep -q "$PLACE2" enabled_functions
> +
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne $((ocnt + 2)) ]; then
> + exit_fail
> +fi
> +
> +# Cleanup Test 3
> +echo 0 > events/test/list_exit/enable
> +echo "-:test/list_exit" >> dynamic_events
> +
> +clear_trace
> --
> 2.43.0