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/time-utils.h | 51 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 tools/perf/util/time-utils.h (limited to 'tools/perf/util/time-utils.h') diff --git a/tools/perf/util/time-utils.h b/tools/perf/util/time-utils.h new file mode 100644 index 000000000..1142b0bdd --- /dev/null +++ b/tools/perf/util/time-utils.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TIME_UTILS_H_ +#define _TIME_UTILS_H_ + +#include +#include +#include + +struct perf_time_interval { + u64 start, end; +}; + +int parse_nsec_time(const char *str, u64 *ptime); + +int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr); + +int perf_time__percent_parse_str(struct perf_time_interval *ptime_buf, int num, + const char *ostr, u64 start, u64 end); + +struct perf_time_interval *perf_time__range_alloc(const char *ostr, int *size); + +bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp); + +bool perf_time__ranges_skip_sample(struct perf_time_interval *ptime_buf, + int num, u64 timestamp); + +struct perf_session; + +int perf_time__parse_for_ranges_reltime(const char *str, struct perf_session *session, + struct perf_time_interval **ranges, + int *range_size, int *range_num, + bool reltime); + +int perf_time__parse_for_ranges(const char *str, struct perf_session *session, + struct perf_time_interval **ranges, + int *range_size, int *range_num); + +int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz); +int timestamp__scnprintf_nsec(u64 timestamp, char *buf, size_t sz); + +int fetch_current_timestamp(char *buf, size_t sz); + +static inline unsigned long long rdclock(void) +{ + struct timespec ts; + + clock_gettime(CLOCK_MONOTONIC, &ts); + return ts.tv_sec * 1000000000ULL + ts.tv_nsec; +} + +#endif -- cgit v1.3.1