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2521f2c2 PO |
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 | ||
2521f2c2 PO |
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 | */ | |
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) { | |
8cbce376 | 36 | gcov_version = gcov_info_version(info); |
2521f2c2 PO |
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 | */ | |
8cbce376 | 47 | gcov_info_link(info); |
2521f2c2 PO |
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 | */ | |
58 | void __gcov_flush(void) | |
59 | { | |
60 | /* Unused. */ | |
61 | } | |
62 | EXPORT_SYMBOL(__gcov_flush); | |
63 | ||
64 | void __gcov_merge_add(gcov_type *counters, unsigned int n_counters) | |
65 | { | |
66 | /* Unused. */ | |
67 | } | |
68 | EXPORT_SYMBOL(__gcov_merge_add); | |
69 | ||
70 | void __gcov_merge_single(gcov_type *counters, unsigned int n_counters) | |
71 | { | |
72 | /* Unused. */ | |
73 | } | |
74 | EXPORT_SYMBOL(__gcov_merge_single); | |
75 | ||
76 | void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters) | |
77 | { | |
78 | /* Unused. */ | |
79 | } | |
80 | EXPORT_SYMBOL(__gcov_merge_delta); | |
81 | ||
82 | /** | |
83 | * gcov_enable_events - enable event reporting through gcov_event() | |
84 | * | |
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. | |
89 | */ | |
90 | void gcov_enable_events(void) | |
91 | { | |
8cbce376 | 92 | struct gcov_info *info = NULL; |
2521f2c2 PO |
93 | |
94 | mutex_lock(&gcov_lock); | |
95 | gcov_events_enabled = 1; | |
8cbce376 | 96 | |
2521f2c2 | 97 | /* Perform event callback for previously registered entries. */ |
8cbce376 | 98 | while ((info = gcov_info_next(info))) |
2521f2c2 | 99 | gcov_event(GCOV_ADD, info); |
8cbce376 | 100 | |
2521f2c2 PO |
101 | mutex_unlock(&gcov_lock); |
102 | } | |
103 | ||
104 | #ifdef CONFIG_MODULES | |
105 | static inline int within(void *addr, void *start, unsigned long size) | |
106 | { | |
107 | return ((addr >= start) && (addr < start + size)); | |
108 | } | |
109 | ||
110 | /* Update list and generate events when modules are unloaded. */ | |
111 | static int gcov_module_notifier(struct notifier_block *nb, unsigned long event, | |
112 | void *data) | |
113 | { | |
114 | struct module *mod = data; | |
8cbce376 FH |
115 | struct gcov_info *info = NULL; |
116 | struct gcov_info *prev = NULL; | |
2521f2c2 PO |
117 | |
118 | if (event != MODULE_STATE_GOING) | |
119 | return NOTIFY_OK; | |
120 | mutex_lock(&gcov_lock); | |
8cbce376 | 121 | |
2521f2c2 | 122 | /* Remove entries located in module from linked list. */ |
8cbce376 | 123 | while ((info = gcov_info_next(info))) { |
2521f2c2 | 124 | if (within(info, mod->module_core, mod->core_size)) { |
8cbce376 | 125 | gcov_info_unlink(prev, info); |
2521f2c2 PO |
126 | if (gcov_events_enabled) |
127 | gcov_event(GCOV_REMOVE, info); | |
128 | } else | |
129 | prev = info; | |
130 | } | |
8cbce376 | 131 | |
2521f2c2 PO |
132 | mutex_unlock(&gcov_lock); |
133 | ||
134 | return NOTIFY_OK; | |
135 | } | |
136 | ||
137 | static struct notifier_block gcov_nb = { | |
138 | .notifier_call = gcov_module_notifier, | |
139 | }; | |
140 | ||
141 | static int __init gcov_init(void) | |
142 | { | |
143 | return register_module_notifier(&gcov_nb); | |
144 | } | |
145 | device_initcall(gcov_init); | |
146 | #endif /* CONFIG_MODULES */ |