[linux-2.6-block.git] / kernel / trace / trace_preemptirq.c

// SPDX-License-Identifier: GPL-2.0
/*
 * preemptoff and irqoff tracepoints
 *
 * Copyright (C) Joel Fernandes (Google) <joel@joelfernandes.org>
 */

#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/kprobes.h>
#include <linux/hardirq.h>
#include "trace.h"

#define CREATE_TRACE_POINTS
#include <trace/events/preemptirq.h>

/*
 * Use regular trace points on architectures that implement noinstr
 * tooling: these calls will only happen with RCU enabled, which can
 * use a regular tracepoint.
 *
 * On older architectures, RCU may not be watching in idle. In that
 * case, wake up RCU to watch while calling the tracepoint. These
 * aren't NMI-safe - so exclude NMI contexts:
 */
#ifdef CONFIG_ARCH_WANTS_NO_INSTR
#define trace(point, args)	trace_##point(args)
#else
#define trace(point, args)					\
	do {							\
		if (trace_##point##_enabled()) {		\
			bool exit_rcu = false;			\
			if (in_nmi())				\
				break;				\
			if (!IS_ENABLED(CONFIG_TINY_RCU) &&	\
			    is_idle_task(current)) {		\
				ct_irq_enter();			\
				exit_rcu = true;		\
			}					\
			trace_##point(args);			\
			if (exit_rcu)				\
				ct_irq_exit();			\
		}						\
	} while (0)
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
/* Per-cpu variable to prevent redundant calls when IRQs already off */
static DEFINE_PER_CPU(int, tracing_irq_cpu);

/*
 * Like trace_hardirqs_on() but without the lockdep invocation. This is
 * used in the low level entry code where the ordering vs. RCU is important
 * and lockdep uses a staged approach which splits the lockdep hardirq
 * tracking into a RCU on and a RCU off section.
 */
void trace_hardirqs_on_prepare(void)
{
	if (this_cpu_read(tracing_irq_cpu)) {
		trace(irq_enable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
		this_cpu_write(tracing_irq_cpu, 0);
	}
}
EXPORT_SYMBOL(trace_hardirqs_on_prepare);
NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);

void trace_hardirqs_on(void)
{
	if (this_cpu_read(tracing_irq_cpu)) {
		trace(irq_enable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
		this_cpu_write(tracing_irq_cpu, 0);
	}

	lockdep_hardirqs_on_prepare();
	lockdep_hardirqs_on(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_on);
NOKPROBE_SYMBOL(trace_hardirqs_on);

/*
 * Like trace_hardirqs_off() but without the lockdep invocation. This is
 * used in the low level entry code where the ordering vs. RCU is important
 * and lockdep uses a staged approach which splits the lockdep hardirq
 * tracking into a RCU on and a RCU off section.
 */
void trace_hardirqs_off_finish(void)
{
	if (!this_cpu_read(tracing_irq_cpu)) {
		this_cpu_write(tracing_irq_cpu, 1);
		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
		trace(irq_disable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	}

}
EXPORT_SYMBOL(trace_hardirqs_off_finish);
NOKPROBE_SYMBOL(trace_hardirqs_off_finish);

void trace_hardirqs_off(void)
{
	lockdep_hardirqs_off(CALLER_ADDR0);

	if (!this_cpu_read(tracing_irq_cpu)) {
		this_cpu_write(tracing_irq_cpu, 1);
		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
		trace(irq_disable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	}
}
EXPORT_SYMBOL(trace_hardirqs_off);
NOKPROBE_SYMBOL(trace_hardirqs_off);
#endif /* CONFIG_TRACE_IRQFLAGS */

#ifdef CONFIG_TRACE_PREEMPT_TOGGLE

void trace_preempt_on(unsigned long a0, unsigned long a1)
{
	trace(preempt_enable, TP_ARGS(a0, a1));
	tracer_preempt_on(a0, a1);
}

void trace_preempt_off(unsigned long a0, unsigned long a1)
{
	trace(preempt_disable, TP_ARGS(a0, a1));
	tracer_preempt_off(a0, a1);
}
#endif
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* preemptoff and irqoff tracepoints
	4	*
	5	* Copyright (C) Joel Fernandes (Google) <joel@joelfernandes.org>
	6	*/
	7
	8	#include <linux/kallsyms.h>
	9	#include <linux/uaccess.h>
	10	#include <linux/module.h>
	11	#include <linux/ftrace.h>
	12	#include <linux/kprobes.h>
	13	#include <linux/hardirq.h>
	14	#include "trace.h"
	15
	16	#define CREATE_TRACE_POINTS
	17	#include <trace/events/preemptirq.h>
	18
	19	/*
	20	* Use regular trace points on architectures that implement noinstr
	21	* tooling: these calls will only happen with RCU enabled, which can
	22	* use a regular tracepoint.
	23	*
	24	* On older architectures, RCU may not be watching in idle. In that
	25	* case, wake up RCU to watch while calling the tracepoint. These
	26	* aren't NMI-safe - so exclude NMI contexts:
	27	*/
	28	#ifdef CONFIG_ARCH_WANTS_NO_INSTR
	29	#define trace(point, args) trace_##point(args)
	30	#else
	31	#define trace(point, args) \
	32	do { \
	33	if (trace_##point##_enabled()) { \
	34	bool exit_rcu = false; \
	35	if (in_nmi()) \
	36	break; \
	37	if (!IS_ENABLED(CONFIG_TINY_RCU) && \
	38	is_idle_task(current)) { \
	39	ct_irq_enter(); \
	40	exit_rcu = true; \
	41	} \
	42	trace_##point(args); \
	43	if (exit_rcu) \
	44	ct_irq_exit(); \
	45	} \
	46	} while (0)
	47	#endif
	48
	49	#ifdef CONFIG_TRACE_IRQFLAGS
	50	/* Per-cpu variable to prevent redundant calls when IRQs already off */
	51	static DEFINE_PER_CPU(int, tracing_irq_cpu);
	52
	53	/*
	54	* Like trace_hardirqs_on() but without the lockdep invocation. This is
	55	* used in the low level entry code where the ordering vs. RCU is important
	56	* and lockdep uses a staged approach which splits the lockdep hardirq
	57	* tracking into a RCU on and a RCU off section.
	58	*/
	59	void trace_hardirqs_on_prepare(void)
	60	{
	61	if (this_cpu_read(tracing_irq_cpu)) {
	62	trace(irq_enable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	63	tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
	64	this_cpu_write(tracing_irq_cpu, 0);
	65	}
	66	}
	67	EXPORT_SYMBOL(trace_hardirqs_on_prepare);
	68	NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
	69
	70	void trace_hardirqs_on(void)
	71	{
	72	if (this_cpu_read(tracing_irq_cpu)) {
	73	trace(irq_enable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	74	tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
	75	this_cpu_write(tracing_irq_cpu, 0);
	76	}
	77
	78	lockdep_hardirqs_on_prepare();
	79	lockdep_hardirqs_on(CALLER_ADDR0);
	80	}
	81	EXPORT_SYMBOL(trace_hardirqs_on);
	82	NOKPROBE_SYMBOL(trace_hardirqs_on);
	83
	84	/*
	85	* Like trace_hardirqs_off() but without the lockdep invocation. This is
	86	* used in the low level entry code where the ordering vs. RCU is important
	87	* and lockdep uses a staged approach which splits the lockdep hardirq
	88	* tracking into a RCU on and a RCU off section.
	89	*/
	90	void trace_hardirqs_off_finish(void)
	91	{
	92	if (!this_cpu_read(tracing_irq_cpu)) {
	93	this_cpu_write(tracing_irq_cpu, 1);
	94	tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
	95	trace(irq_disable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	96	}
	97
	98	}
	99	EXPORT_SYMBOL(trace_hardirqs_off_finish);
	100	NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
	101
	102	void trace_hardirqs_off(void)
	103	{
	104	lockdep_hardirqs_off(CALLER_ADDR0);
	105
	106	if (!this_cpu_read(tracing_irq_cpu)) {
	107	this_cpu_write(tracing_irq_cpu, 1);
	108	tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
	109	trace(irq_disable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));
	110	}
	111	}
	112	EXPORT_SYMBOL(trace_hardirqs_off);
	113	NOKPROBE_SYMBOL(trace_hardirqs_off);
	114	#endif /* CONFIG_TRACE_IRQFLAGS */
	115
	116	#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
	117
	118	void trace_preempt_on(unsigned long a0, unsigned long a1)
	119	{
	120	trace(preempt_enable, TP_ARGS(a0, a1));
	121	tracer_preempt_on(a0, a1);
	122	}
	123
	124	void trace_preempt_off(unsigned long a0, unsigned long a1)
	125	{
	126	trace(preempt_disable, TP_ARGS(a0, a1));
	127	tracer_preempt_off(a0, a1);
	128	}
	129	#endif