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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 "trace.h"
14
15#define CREATE_TRACE_POINTS
16#include <trace/events/preemptirq.h>
17
18#ifdef CONFIG_TRACE_IRQFLAGS
19/* Per-cpu variable to prevent redundant calls when IRQs already off */
20static DEFINE_PER_CPU(int, tracing_irq_cpu);
21
22/*
23 * Like trace_hardirqs_on() but without the lockdep invocation. This is
24 * used in the low level entry code where the ordering vs. RCU is important
25 * and lockdep uses a staged approach which splits the lockdep hardirq
26 * tracking into a RCU on and a RCU off section.
27 */
28void trace_hardirqs_on_prepare(void)
29{
30 if (this_cpu_read(tracing_irq_cpu)) {
31 if (!in_nmi())
32 trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
33 tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
34 this_cpu_write(tracing_irq_cpu, 0);
35 }
36}
37EXPORT_SYMBOL(trace_hardirqs_on_prepare);
38NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
39
40void trace_hardirqs_on(void)
41{
42 if (this_cpu_read(tracing_irq_cpu)) {
43 if (!in_nmi())
44 trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
45 tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
46 this_cpu_write(tracing_irq_cpu, 0);
47 }
48
49 lockdep_hardirqs_on_prepare();
50 lockdep_hardirqs_on(CALLER_ADDR0);
51}
52EXPORT_SYMBOL(trace_hardirqs_on);
53NOKPROBE_SYMBOL(trace_hardirqs_on);
54
55/*
56 * Like trace_hardirqs_off() but without the lockdep invocation. This is
57 * used in the low level entry code where the ordering vs. RCU is important
58 * and lockdep uses a staged approach which splits the lockdep hardirq
59 * tracking into a RCU on and a RCU off section.
60 */
61void trace_hardirqs_off_finish(void)
62{
63 if (!this_cpu_read(tracing_irq_cpu)) {
64 this_cpu_write(tracing_irq_cpu, 1);
65 tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
66 if (!in_nmi())
67 trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
68 }
69
70}
71EXPORT_SYMBOL(trace_hardirqs_off_finish);
72NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
73
74void trace_hardirqs_off(void)
75{
76 lockdep_hardirqs_off(CALLER_ADDR0);
77
78 if (!this_cpu_read(tracing_irq_cpu)) {
79 this_cpu_write(tracing_irq_cpu, 1);
80 tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
81 if (!in_nmi())
82 trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
83 }
84}
85EXPORT_SYMBOL(trace_hardirqs_off);
86NOKPROBE_SYMBOL(trace_hardirqs_off);
87
88__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
89{
90 if (this_cpu_read(tracing_irq_cpu)) {
91 if (!in_nmi())
92 trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
93 tracer_hardirqs_on(CALLER_ADDR0, caller_addr);
94 this_cpu_write(tracing_irq_cpu, 0);
95 }
96
97 lockdep_hardirqs_on_prepare();
98 lockdep_hardirqs_on(caller_addr);
99}
100EXPORT_SYMBOL(trace_hardirqs_on_caller);
101NOKPROBE_SYMBOL(trace_hardirqs_on_caller);
102
103__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
104{
105 lockdep_hardirqs_off(caller_addr);
106
107 if (!this_cpu_read(tracing_irq_cpu)) {
108 this_cpu_write(tracing_irq_cpu, 1);
109 tracer_hardirqs_off(CALLER_ADDR0, caller_addr);
110 if (!in_nmi())
111 trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
112 }
113}
114EXPORT_SYMBOL(trace_hardirqs_off_caller);
115NOKPROBE_SYMBOL(trace_hardirqs_off_caller);
116#endif /* CONFIG_TRACE_IRQFLAGS */
117
118#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
119
120void trace_preempt_on(unsigned long a0, unsigned long a1)
121{
122 if (!in_nmi())
123 trace_preempt_enable_rcuidle(a0, a1);
124 tracer_preempt_on(a0, a1);
125}
126
127void trace_preempt_off(unsigned long a0, unsigned long a1)
128{
129 if (!in_nmi())
130 trace_preempt_disable_rcuidle(a0, a1);
131 tracer_preempt_off(a0, a1);
132}
133#endif
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 */
51static 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 */
59void 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}
67EXPORT_SYMBOL(trace_hardirqs_on_prepare);
68NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
69
70void 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}
81EXPORT_SYMBOL(trace_hardirqs_on);
82NOKPROBE_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 */
90void 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}
99EXPORT_SYMBOL(trace_hardirqs_off_finish);
100NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
101
102void 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}
112EXPORT_SYMBOL(trace_hardirqs_off);
113NOKPROBE_SYMBOL(trace_hardirqs_off);
114#endif /* CONFIG_TRACE_IRQFLAGS */
115
116#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
117
118void 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
124void 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