2 * This code maintains a list of active profiling data structures.
4 * Copyright IBM Corp. 2009
5 * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
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>
16 #define pr_fmt(fmt) "gcov: " fmt
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
23 static int gcov_events_enabled;
24 static DEFINE_MUTEX(gcov_lock);
27 * __gcov_init is called by gcc-generated constructor code for each object
28 * file compiled with -fprofile-arcs.
30 void __gcov_init(struct gcov_info *info)
32 static unsigned int gcov_version;
34 mutex_lock(&gcov_lock);
35 if (gcov_version == 0) {
36 gcov_version = gcov_info_version(info);
38 * Printing gcc's version magic may prove useful for debugging
39 * incompatibility reports.
41 pr_info("version magic: 0x%x\n", gcov_version);
44 * Add new profiling data structure to list and inform event
48 if (gcov_events_enabled)
49 gcov_event(GCOV_ADD, info);
50 mutex_unlock(&gcov_lock);
52 EXPORT_SYMBOL(__gcov_init);
55 * These functions may be referenced by gcc-generated profiling code but serve
56 * no function for kernel profiling.
58 void __gcov_flush(void)
62 EXPORT_SYMBOL(__gcov_flush);
64 void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
68 EXPORT_SYMBOL(__gcov_merge_add);
70 void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
74 EXPORT_SYMBOL(__gcov_merge_single);
76 void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
80 EXPORT_SYMBOL(__gcov_merge_delta);
83 * gcov_enable_events - enable event reporting through gcov_event()
85 * Turn on reporting of profiling data load/unload-events through the
86 * gcov_event() callback. Also replay all previous events once. This function
87 * is needed because some events are potentially generated too early for the
88 * callback implementation to handle them initially.
90 void gcov_enable_events(void)
92 struct gcov_info *info = NULL;
94 mutex_lock(&gcov_lock);
95 gcov_events_enabled = 1;
97 /* Perform event callback for previously registered entries. */
98 while ((info = gcov_info_next(info)))
99 gcov_event(GCOV_ADD, info);
101 mutex_unlock(&gcov_lock);
104 #ifdef CONFIG_MODULES
105 static inline int within(void *addr, void *start, unsigned long size)
107 return ((addr >= start) && (addr < start + size));
110 /* Update list and generate events when modules are unloaded. */
111 static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
114 struct module *mod = data;
115 struct gcov_info *info = NULL;
116 struct gcov_info *prev = NULL;
118 if (event != MODULE_STATE_GOING)
120 mutex_lock(&gcov_lock);
122 /* Remove entries located in module from linked list. */
123 while ((info = gcov_info_next(info))) {
124 if (within(info, mod->module_core, mod->core_size)) {
125 gcov_info_unlink(prev, info);
126 if (gcov_events_enabled)
127 gcov_event(GCOV_REMOVE, info);
132 mutex_unlock(&gcov_lock);
137 static struct notifier_block gcov_nb = {
138 .notifier_call = gcov_module_notifier,
141 static int __init gcov_init(void)
143 return register_module_notifier(&gcov_nb);
145 device_initcall(gcov_init);
146 #endif /* CONFIG_MODULES */