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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This code maintains a list of active profiling data structures.
4 *
5 * Copyright IBM Corp. 2009
6 * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
7 *
8 * Uses gcc-internal data definitions.
9 * Based on the gcov-kernel patch by:
10 * Hubertus Franke <frankeh@us.ibm.com>
11 * Nigel Hinds <nhinds@us.ibm.com>
12 * Rajan Ravindran <rajancr@us.ibm.com>
13 * Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
14 * Paul Larson
15 */
16
17#define pr_fmt(fmt) "gcov: " fmt
18
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/mutex.h>
22#include <linux/sched.h>
23#include "gcov.h"
24
25int gcov_events_enabled;
26DEFINE_MUTEX(gcov_lock);
27
28/**
29 * gcov_enable_events - enable event reporting through gcov_event()
30 *
31 * Turn on reporting of profiling data load/unload-events through the
32 * gcov_event() callback. Also replay all previous events once. This function
33 * is needed because some events are potentially generated too early for the
34 * callback implementation to handle them initially.
35 */
36void gcov_enable_events(void)
37{
38 struct gcov_info *info = NULL;
39
40 mutex_lock(&gcov_lock);
41 gcov_events_enabled = 1;
42
43 /* Perform event callback for previously registered entries. */
44 while ((info = gcov_info_next(info))) {
45 gcov_event(GCOV_ADD, info);
46 cond_resched();
47 }
48
49 mutex_unlock(&gcov_lock);
50}
51
52#ifdef CONFIG_MODULES
53/* Update list and generate events when modules are unloaded. */
54static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
55 void *data)
56{
57 struct module *mod = data;
58 struct gcov_info *info = NULL;
59 struct gcov_info *prev = NULL;
60
61 if (event != MODULE_STATE_GOING)
62 return NOTIFY_OK;
63 mutex_lock(&gcov_lock);
64
65 /* Remove entries located in module from linked list. */
66 while ((info = gcov_info_next(info))) {
67 if (gcov_info_within_module(info, mod)) {
68 gcov_info_unlink(prev, info);
69 if (gcov_events_enabled)
70 gcov_event(GCOV_REMOVE, info);
71 } else
72 prev = info;
73 }
74
75 mutex_unlock(&gcov_lock);
76
77 return NOTIFY_OK;
78}
79
80static struct notifier_block gcov_nb = {
81 .notifier_call = gcov_module_notifier,
82};
83
84static int __init gcov_init(void)
85{
86 return register_module_notifier(&gcov_nb);
87}
88device_initcall(gcov_init);
89#endif /* CONFIG_MODULES */
1/*
2 * This code maintains a list of active profiling data structures.
3 *
4 * Copyright IBM Corp. 2009
5 * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
6 *
7 * Uses gcc-internal data definitions.
8 * Based on the gcov-kernel patch by:
9 * Hubertus Franke <frankeh@us.ibm.com>
10 * Nigel Hinds <nhinds@us.ibm.com>
11 * Rajan Ravindran <rajancr@us.ibm.com>
12 * Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
13 * Paul Larson
14 */
15
16#define pr_fmt(fmt) "gcov: " fmt
17
18#include <linux/init.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include "gcov.h"
22
23static int gcov_events_enabled;
24static DEFINE_MUTEX(gcov_lock);
25
26/*
27 * __gcov_init is called by gcc-generated constructor code for each object
28 * file compiled with -fprofile-arcs.
29 */
30void __gcov_init(struct gcov_info *info)
31{
32 static unsigned int gcov_version;
33
34 mutex_lock(&gcov_lock);
35 if (gcov_version == 0) {
36 gcov_version = gcov_info_version(info);
37 /*
38 * Printing gcc's version magic may prove useful for debugging
39 * incompatibility reports.
40 */
41 pr_info("version magic: 0x%x\n", gcov_version);
42 }
43 /*
44 * Add new profiling data structure to list and inform event
45 * listener.
46 */
47 gcov_info_link(info);
48 if (gcov_events_enabled)
49 gcov_event(GCOV_ADD, info);
50 mutex_unlock(&gcov_lock);
51}
52EXPORT_SYMBOL(__gcov_init);
53
54/*
55 * These functions may be referenced by gcc-generated profiling code but serve
56 * no function for kernel profiling.
57 */
58void __gcov_flush(void)
59{
60 /* Unused. */
61}
62EXPORT_SYMBOL(__gcov_flush);
63
64void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
65{
66 /* Unused. */
67}
68EXPORT_SYMBOL(__gcov_merge_add);
69
70void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
71{
72 /* Unused. */
73}
74EXPORT_SYMBOL(__gcov_merge_single);
75
76void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
77{
78 /* Unused. */
79}
80EXPORT_SYMBOL(__gcov_merge_delta);
81
82void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
83{
84 /* Unused. */
85}
86EXPORT_SYMBOL(__gcov_merge_ior);
87
88/**
89 * gcov_enable_events - enable event reporting through gcov_event()
90 *
91 * Turn on reporting of profiling data load/unload-events through the
92 * gcov_event() callback. Also replay all previous events once. This function
93 * is needed because some events are potentially generated too early for the
94 * callback implementation to handle them initially.
95 */
96void gcov_enable_events(void)
97{
98 struct gcov_info *info = NULL;
99
100 mutex_lock(&gcov_lock);
101 gcov_events_enabled = 1;
102
103 /* Perform event callback for previously registered entries. */
104 while ((info = gcov_info_next(info)))
105 gcov_event(GCOV_ADD, info);
106
107 mutex_unlock(&gcov_lock);
108}
109
110#ifdef CONFIG_MODULES
111static inline int within(void *addr, void *start, unsigned long size)
112{
113 return ((addr >= start) && (addr < start + size));
114}
115
116/* Update list and generate events when modules are unloaded. */
117static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
118 void *data)
119{
120 struct module *mod = data;
121 struct gcov_info *info = NULL;
122 struct gcov_info *prev = NULL;
123
124 if (event != MODULE_STATE_GOING)
125 return NOTIFY_OK;
126 mutex_lock(&gcov_lock);
127
128 /* Remove entries located in module from linked list. */
129 while ((info = gcov_info_next(info))) {
130 if (within(info, mod->module_core, mod->core_size)) {
131 gcov_info_unlink(prev, info);
132 if (gcov_events_enabled)
133 gcov_event(GCOV_REMOVE, info);
134 } else
135 prev = info;
136 }
137
138 mutex_unlock(&gcov_lock);
139
140 return NOTIFY_OK;
141}
142
143static struct notifier_block gcov_nb = {
144 .notifier_call = gcov_module_notifier,
145};
146
147static int __init gcov_init(void)
148{
149 return register_module_notifier(&gcov_nb);
150}
151device_initcall(gcov_init);
152#endif /* CONFIG_MODULES */