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 --- drivers/ptp/ptp_fc3.h | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/ptp/ptp_fc3.h (limited to 'drivers/ptp/ptp_fc3.h') diff --git a/drivers/ptp/ptp_fc3.h b/drivers/ptp/ptp_fc3.h new file mode 100644 index 000000000..897101579 --- /dev/null +++ b/drivers/ptp/ptp_fc3.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * PTP hardware clock driver for the FemtoClock3 family of timing and + * synchronization devices. + * + * Copyright (C) 2023 Integrated Device Technology, Inc., a Renesas Company. + */ +#ifndef PTP_IDTFC3_H +#define PTP_IDTFC3_H + +#include +#include +#include + +#define FW_FILENAME "idtfc3.bin" + +#define MAX_FFO_PPB (244000) +#define TDC_GET_PERIOD (10) + +struct idtfc3 { + struct ptp_clock_info caps; + struct ptp_clock *ptp_clock; + struct device *dev; + /* Mutex to protect operations from being interrupted */ + struct mutex *lock; + struct device *mfd; + struct regmap *regmap; + struct idtfc3_hw_param hw_param; + u32 sub_sync_count; + u32 ns_per_sync; + int tdc_offset_sign; + u64 tdc_apll_freq; + u32 time_ref_freq; + u16 fod_n; + u8 lpf_mode; + /* Time counter */ + u32 last_counter; + s64 ns; + u32 ns_per_counter; + u32 tc_update_period; + u32 tc_write_timeout; + s64 tod_write_overhead; +}; + +#endif /* PTP_IDTFC3_H */ -- cgit v1.3.1