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/perf/util/iostat.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 tools/perf/util/iostat.c (limited to 'tools/perf/util/iostat.c') diff --git a/tools/perf/util/iostat.c b/tools/perf/util/iostat.c new file mode 100644 index 000000000..c9d5028a4 --- /dev/null +++ b/tools/perf/util/iostat.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "util/iostat.h" +#include "util/debug.h" + +enum iostat_mode_t iostat_mode = IOSTAT_NONE; + +__weak int iostat_prepare(struct evlist **evlist __maybe_unused, + struct perf_stat_config *config __maybe_unused) +{ + return -1; +} + +__weak int iostat_parse(const struct option *opt __maybe_unused, + const char *str __maybe_unused, + int unset __maybe_unused) +{ + pr_err("iostat mode is not supported on current platform\n"); + return -1; +} + +__weak void iostat_list(struct evlist *evlist __maybe_unused, + struct perf_stat_config *config __maybe_unused) +{ +} + +__weak void iostat_release(struct evlist *evlist __maybe_unused) +{ +} + +__weak void iostat_print_header_prefix(struct perf_stat_config *config __maybe_unused) +{ +} + +__weak void iostat_print_metric(struct perf_stat_config *config __maybe_unused, + struct evsel *evsel __maybe_unused, + struct perf_stat_output_ctx *out __maybe_unused) +{ +} + +__weak void iostat_prefix(struct evlist *evlist __maybe_unused, + struct perf_stat_config *config __maybe_unused, + char *prefix __maybe_unused, + struct timespec *ts __maybe_unused) +{ +} + +__weak void iostat_print_counters(struct evlist *evlist __maybe_unused, + struct perf_stat_config *config __maybe_unused, + struct timespec *ts __maybe_unused, + char *prefix __maybe_unused, + iostat_print_counter_t print_cnt_cb __maybe_unused, + void *arg __maybe_unused) +{ +} -- cgit v1.3.1