From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- tools/testing/selftests/dt/.gitignore | 1 + tools/testing/selftests/dt/Makefile | 21 +++++ tools/testing/selftests/dt/compatible_ignore_list | 1 + .../testing/selftests/dt/test_unprobed_devices.sh | 93 ++++++++++++++++++++++ 4 files changed, 116 insertions(+) create mode 100644 tools/testing/selftests/dt/.gitignore create mode 100644 tools/testing/selftests/dt/Makefile create mode 100644 tools/testing/selftests/dt/compatible_ignore_list create mode 100755 tools/testing/selftests/dt/test_unprobed_devices.sh (limited to 'tools/testing/selftests/dt') diff --git a/tools/testing/selftests/dt/.gitignore b/tools/testing/selftests/dt/.gitignore new file mode 100644 index 000000000..f6476c9f2 --- /dev/null +++ b/tools/testing/selftests/dt/.gitignore @@ -0,0 +1 @@ +compatible_list diff --git a/tools/testing/selftests/dt/Makefile b/tools/testing/selftests/dt/Makefile new file mode 100644 index 000000000..2d33ee9e9 --- /dev/null +++ b/tools/testing/selftests/dt/Makefile @@ -0,0 +1,21 @@ +PY3 = $(shell which python3 2>/dev/null) + +ifneq ($(PY3),) + +TEST_PROGS := test_unprobed_devices.sh +TEST_GEN_FILES := compatible_list +TEST_FILES := compatible_ignore_list + +include ../lib.mk + +$(OUTPUT)/compatible_list: + $(top_srcdir)/scripts/dtc/dt-extract-compatibles -d $(top_srcdir) > $@ + +else + +all: no_py3_warning + +no_py3_warning: + @echo "Missing python3. This test will be skipped." + +endif diff --git a/tools/testing/selftests/dt/compatible_ignore_list b/tools/testing/selftests/dt/compatible_ignore_list new file mode 100644 index 000000000..1323903fe --- /dev/null +++ b/tools/testing/selftests/dt/compatible_ignore_list @@ -0,0 +1 @@ +simple-mfd diff --git a/tools/testing/selftests/dt/test_unprobed_devices.sh b/tools/testing/selftests/dt/test_unprobed_devices.sh new file mode 100755 index 000000000..5e3f42ef2 --- /dev/null +++ b/tools/testing/selftests/dt/test_unprobed_devices.sh @@ -0,0 +1,93 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2023 Collabora Ltd +# +# Based on Frank Rowand's dt_stat script. +# +# This script tests for devices that were declared on the Devicetree and are +# expected to bind to a driver, but didn't. +# +# To achieve this, two lists are used: +# * a list of the compatibles that can be matched by a Devicetree node +# * a list of compatibles that should be ignored +# + +DIR="$(dirname $(readlink -f "$0"))" + +source "${DIR}"/../kselftest/ktap_helpers.sh + +PDT=/proc/device-tree/ +COMPAT_LIST="${DIR}"/compatible_list +IGNORE_LIST="${DIR}"/compatible_ignore_list + +ktap_print_header + +if [[ ! -d "${PDT}" ]]; then + ktap_skip_all "${PDT} doesn't exist." + exit "${KSFT_SKIP}" +fi + +nodes_compatible=$( + for node in $(find ${PDT} -type d); do + [ ! -f "${node}"/compatible ] && continue + # Check if node is available + if [[ -e "${node}"/status ]]; then + status=$(tr -d '\000' < "${node}"/status) + if [[ "${status}" != "okay" && "${status}" != "ok" ]]; then + if [ -n "${disabled_nodes_regex}" ]; then + disabled_nodes_regex="${disabled_nodes_regex}|${node}" + else + disabled_nodes_regex="${node}" + fi + continue + fi + fi + + # Ignore this node if one of its ancestors was disabled + if [ -n "${disabled_nodes_regex}" ]; then + echo "${node}" | grep -q -E "${disabled_nodes_regex}" && continue + fi + + echo "${node}" | sed -e 's|\/proc\/device-tree||' + done | sort + ) + +nodes_dev_bound=$( + IFS=$'\n' + for dev_dir in $(find /sys/devices -type d); do + [ ! -f "${dev_dir}"/uevent ] && continue + [ ! -d "${dev_dir}"/driver ] && continue + + grep '^OF_FULLNAME=' "${dev_dir}"/uevent | sed -e 's|OF_FULLNAME=||' + done + ) + +num_tests=$(echo ${nodes_compatible} | wc -w) +ktap_set_plan "${num_tests}" + +retval="${KSFT_PASS}" +for node in ${nodes_compatible}; do + if ! echo "${nodes_dev_bound}" | grep -E -q "(^| )${node}( |\$)"; then + compatibles=$(tr '\000' '\n' < "${PDT}"/"${node}"/compatible) + + for compatible in ${compatibles}; do + if grep -x -q "${compatible}" "${IGNORE_LIST}"; then + continue + fi + + if grep -x -q "${compatible}" "${COMPAT_LIST}"; then + ktap_test_fail "${node}" + retval="${KSFT_FAIL}" + continue 2 + fi + done + ktap_test_skip "${node}" + else + ktap_test_pass "${node}" + fi + +done + +ktap_print_totals +exit "${retval}" -- cgit v1.3.1