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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2521f2c2 PO |
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> | |
9d796e66 | 22 | #include <linux/sched.h> |
2521f2c2 PO |
23 | #include "gcov.h" |
24 | ||
2521f2c2 PO |
25 | static int gcov_events_enabled; |
26 | static DEFINE_MUTEX(gcov_lock); | |
27 | ||
28 | /* | |
29 | * __gcov_init is called by gcc-generated constructor code for each object | |
30 | * file compiled with -fprofile-arcs. | |
31 | */ | |
32 | void __gcov_init(struct gcov_info *info) | |
33 | { | |
34 | static unsigned int gcov_version; | |
35 | ||
36 | mutex_lock(&gcov_lock); | |
37 | if (gcov_version == 0) { | |
8cbce376 | 38 | gcov_version = gcov_info_version(info); |
2521f2c2 PO |
39 | /* |
40 | * Printing gcc's version magic may prove useful for debugging | |
41 | * incompatibility reports. | |
42 | */ | |
43 | pr_info("version magic: 0x%x\n", gcov_version); | |
44 | } | |
45 | /* | |
46 | * Add new profiling data structure to list and inform event | |
47 | * listener. | |
48 | */ | |
8cbce376 | 49 | gcov_info_link(info); |
2521f2c2 PO |
50 | if (gcov_events_enabled) |
51 | gcov_event(GCOV_ADD, info); | |
52 | mutex_unlock(&gcov_lock); | |
53 | } | |
54 | EXPORT_SYMBOL(__gcov_init); | |
55 | ||
56 | /* | |
57 | * These functions may be referenced by gcc-generated profiling code but serve | |
58 | * no function for kernel profiling. | |
59 | */ | |
60 | void __gcov_flush(void) | |
61 | { | |
62 | /* Unused. */ | |
63 | } | |
64 | EXPORT_SYMBOL(__gcov_flush); | |
65 | ||
66 | void __gcov_merge_add(gcov_type *counters, unsigned int n_counters) | |
67 | { | |
68 | /* Unused. */ | |
69 | } | |
70 | EXPORT_SYMBOL(__gcov_merge_add); | |
71 | ||
72 | void __gcov_merge_single(gcov_type *counters, unsigned int n_counters) | |
73 | { | |
74 | /* Unused. */ | |
75 | } | |
76 | EXPORT_SYMBOL(__gcov_merge_single); | |
77 | ||
78 | void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters) | |
79 | { | |
80 | /* Unused. */ | |
81 | } | |
82 | EXPORT_SYMBOL(__gcov_merge_delta); | |
83 | ||
5f41ea03 FH |
84 | void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters) |
85 | { | |
86 | /* Unused. */ | |
87 | } | |
88 | EXPORT_SYMBOL(__gcov_merge_ior); | |
89 | ||
a992bf83 YP |
90 | void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters) |
91 | { | |
92 | /* Unused. */ | |
93 | } | |
94 | EXPORT_SYMBOL(__gcov_merge_time_profile); | |
95 | ||
3e44c471 LS |
96 | void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters) |
97 | { | |
98 | /* Unused. */ | |
99 | } | |
100 | EXPORT_SYMBOL(__gcov_merge_icall_topn); | |
101 | ||
05384213 ML |
102 | void __gcov_exit(void) |
103 | { | |
104 | /* Unused. */ | |
105 | } | |
106 | EXPORT_SYMBOL(__gcov_exit); | |
107 | ||
2521f2c2 PO |
108 | /** |
109 | * gcov_enable_events - enable event reporting through gcov_event() | |
110 | * | |
111 | * Turn on reporting of profiling data load/unload-events through the | |
112 | * gcov_event() callback. Also replay all previous events once. This function | |
113 | * is needed because some events are potentially generated too early for the | |
114 | * callback implementation to handle them initially. | |
115 | */ | |
116 | void gcov_enable_events(void) | |
117 | { | |
8cbce376 | 118 | struct gcov_info *info = NULL; |
2521f2c2 PO |
119 | |
120 | mutex_lock(&gcov_lock); | |
121 | gcov_events_enabled = 1; | |
8cbce376 | 122 | |
2521f2c2 | 123 | /* Perform event callback for previously registered entries. */ |
9d796e66 | 124 | while ((info = gcov_info_next(info))) { |
2521f2c2 | 125 | gcov_event(GCOV_ADD, info); |
9d796e66 AR |
126 | cond_resched(); |
127 | } | |
8cbce376 | 128 | |
2521f2c2 PO |
129 | mutex_unlock(&gcov_lock); |
130 | } | |
131 | ||
132 | #ifdef CONFIG_MODULES | |
2521f2c2 PO |
133 | /* Update list and generate events when modules are unloaded. */ |
134 | static int gcov_module_notifier(struct notifier_block *nb, unsigned long event, | |
135 | void *data) | |
136 | { | |
137 | struct module *mod = data; | |
8cbce376 FH |
138 | struct gcov_info *info = NULL; |
139 | struct gcov_info *prev = NULL; | |
2521f2c2 PO |
140 | |
141 | if (event != MODULE_STATE_GOING) | |
142 | return NOTIFY_OK; | |
143 | mutex_lock(&gcov_lock); | |
8cbce376 | 144 | |
2521f2c2 | 145 | /* Remove entries located in module from linked list. */ |
8cbce376 | 146 | while ((info = gcov_info_next(info))) { |
c65abf35 | 147 | if (within_module((unsigned long)info, mod)) { |
8cbce376 | 148 | gcov_info_unlink(prev, info); |
2521f2c2 PO |
149 | if (gcov_events_enabled) |
150 | gcov_event(GCOV_REMOVE, info); | |
151 | } else | |
152 | prev = info; | |
153 | } | |
8cbce376 | 154 | |
2521f2c2 PO |
155 | mutex_unlock(&gcov_lock); |
156 | ||
157 | return NOTIFY_OK; | |
158 | } | |
159 | ||
160 | static struct notifier_block gcov_nb = { | |
161 | .notifier_call = gcov_module_notifier, | |
162 | }; | |
163 | ||
164 | static int __init gcov_init(void) | |
165 | { | |
166 | return register_module_notifier(&gcov_nb); | |
167 | } | |
168 | device_initcall(gcov_init); | |
169 | #endif /* CONFIG_MODULES */ |