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
23 static int gcov_events_enabled;
24 static 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 */
__gcov_init(struct gcov_info * info)30 void __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 }
52 EXPORT_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 */
__gcov_flush(void)58 void __gcov_flush(void)
59 {
60 /* Unused. */
61 }
62 EXPORT_SYMBOL(__gcov_flush);
63
__gcov_merge_add(gcov_type * counters,unsigned int n_counters)64 void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
65 {
66 /* Unused. */
67 }
68 EXPORT_SYMBOL(__gcov_merge_add);
69
__gcov_merge_single(gcov_type * counters,unsigned int n_counters)70 void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
71 {
72 /* Unused. */
73 }
74 EXPORT_SYMBOL(__gcov_merge_single);
75
__gcov_merge_delta(gcov_type * counters,unsigned int n_counters)76 void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
77 {
78 /* Unused. */
79 }
80 EXPORT_SYMBOL(__gcov_merge_delta);
81
__gcov_merge_ior(gcov_type * counters,unsigned int n_counters)82 void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
83 {
84 /* Unused. */
85 }
86 EXPORT_SYMBOL(__gcov_merge_ior);
87
__gcov_merge_time_profile(gcov_type * counters,unsigned int n_counters)88 void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
89 {
90 /* Unused. */
91 }
92 EXPORT_SYMBOL(__gcov_merge_time_profile);
93
__gcov_merge_icall_topn(gcov_type * counters,unsigned int n_counters)94 void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
95 {
96 /* Unused. */
97 }
98 EXPORT_SYMBOL(__gcov_merge_icall_topn);
99
__gcov_exit(void)100 void __gcov_exit(void)
101 {
102 /* Unused. */
103 }
104 EXPORT_SYMBOL(__gcov_exit);
105
106 /**
107 * gcov_enable_events - enable event reporting through gcov_event()
108 *
109 * Turn on reporting of profiling data load/unload-events through the
110 * gcov_event() callback. Also replay all previous events once. This function
111 * is needed because some events are potentially generated too early for the
112 * callback implementation to handle them initially.
113 */
gcov_enable_events(void)114 void gcov_enable_events(void)
115 {
116 struct gcov_info *info = NULL;
117
118 mutex_lock(&gcov_lock);
119 gcov_events_enabled = 1;
120
121 /* Perform event callback for previously registered entries. */
122 while ((info = gcov_info_next(info)))
123 gcov_event(GCOV_ADD, info);
124
125 mutex_unlock(&gcov_lock);
126 }
127
128 #ifdef CONFIG_MODULES
within(void * addr,void * start,unsigned long size)129 static inline int within(void *addr, void *start, unsigned long size)
130 {
131 return ((addr >= start) && (addr < start + size));
132 }
133
134 /* Update list and generate events when modules are unloaded. */
gcov_module_notifier(struct notifier_block * nb,unsigned long event,void * data)135 static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
136 void *data)
137 {
138 struct module *mod = data;
139 struct gcov_info *info = NULL;
140 struct gcov_info *prev = NULL;
141
142 if (event != MODULE_STATE_GOING)
143 return NOTIFY_OK;
144 mutex_lock(&gcov_lock);
145
146 /* Remove entries located in module from linked list. */
147 while ((info = gcov_info_next(info))) {
148 if (within(info, mod->module_core, mod->core_size)) {
149 gcov_info_unlink(prev, info);
150 if (gcov_events_enabled)
151 gcov_event(GCOV_REMOVE, info);
152 } else
153 prev = info;
154 }
155
156 mutex_unlock(&gcov_lock);
157
158 return NOTIFY_OK;
159 }
160
161 static struct notifier_block gcov_nb = {
162 .notifier_call = gcov_module_notifier,
163 };
164
gcov_init(void)165 static int __init gcov_init(void)
166 {
167 return register_module_notifier(&gcov_nb);
168 }
169 device_initcall(gcov_init);
170 #endif /* CONFIG_MODULES */
171