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/clocksource/timer-of.h | 72 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 drivers/clocksource/timer-of.h (limited to 'drivers/clocksource/timer-of.h') diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h new file mode 100644 index 000000000..74a632b85 --- /dev/null +++ b/drivers/clocksource/timer-of.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __TIMER_OF_H__ +#define __TIMER_OF_H__ + +#include + +#define TIMER_OF_BASE 0x1 +#define TIMER_OF_CLOCK 0x2 +#define TIMER_OF_IRQ 0x4 + +struct of_timer_irq { + int irq; + int index; + const char *name; + unsigned long flags; + irq_handler_t handler; +}; + +struct of_timer_base { + void __iomem *base; + const char *name; + int index; +}; + +struct of_timer_clk { + struct clk *clk; + const char *name; + int index; + unsigned long rate; + unsigned long period; +}; + +struct timer_of { + unsigned int flags; + struct device_node *np; + struct clock_event_device clkevt; + struct of_timer_base of_base; + struct of_timer_irq of_irq; + struct of_timer_clk of_clk; + void *private_data; +}; + +static inline struct timer_of *to_timer_of(struct clock_event_device *clkevt) +{ + return container_of(clkevt, struct timer_of, clkevt); +} + +static inline void __iomem *timer_of_base(struct timer_of *to) +{ + return to->of_base.base; +} + +static inline int timer_of_irq(struct timer_of *to) +{ + return to->of_irq.irq; +} + +static inline unsigned long timer_of_rate(struct timer_of *to) +{ + return to->of_clk.rate; +} + +static inline unsigned long timer_of_period(struct timer_of *to) +{ + return to->of_clk.period; +} + +int timer_of_init(struct device_node *np, struct timer_of *to); + +void timer_of_cleanup(struct timer_of *to); + +#endif -- cgit v1.3.1