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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// 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 */