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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 | ||
826eba0d GH |
25 | int gcov_events_enabled; |
26 | DEFINE_MUTEX(gcov_lock); | |
05384213 | 27 | |
2521f2c2 PO |
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 | */ | |
36 | void gcov_enable_events(void) | |
37 | { | |
8cbce376 | 38 | struct gcov_info *info = NULL; |
2521f2c2 PO |
39 | |
40 | mutex_lock(&gcov_lock); | |
41 | gcov_events_enabled = 1; | |
8cbce376 | 42 | |
2521f2c2 | 43 | /* Perform event callback for previously registered entries. */ |
9d796e66 | 44 | while ((info = gcov_info_next(info))) { |
2521f2c2 | 45 | gcov_event(GCOV_ADD, info); |
9d796e66 AR |
46 | cond_resched(); |
47 | } | |
8cbce376 | 48 | |
2521f2c2 PO |
49 | mutex_unlock(&gcov_lock); |
50 | } | |
51 | ||
52 | #ifdef CONFIG_MODULES | |
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53 | /* Update list and generate events when modules are unloaded. */ |
54 | static int gcov_module_notifier(struct notifier_block *nb, unsigned long event, | |
55 | void *data) | |
56 | { | |
57 | struct module *mod = data; | |
8cbce376 FH |
58 | struct gcov_info *info = NULL; |
59 | struct gcov_info *prev = NULL; | |
2521f2c2 PO |
60 | |
61 | if (event != MODULE_STATE_GOING) | |
62 | return NOTIFY_OK; | |
63 | mutex_lock(&gcov_lock); | |
8cbce376 | 64 | |
2521f2c2 | 65 | /* Remove entries located in module from linked list. */ |
8cbce376 | 66 | while ((info = gcov_info_next(info))) { |
e178a5be | 67 | if (gcov_info_within_module(info, mod)) { |
8cbce376 | 68 | gcov_info_unlink(prev, info); |
2521f2c2 PO |
69 | if (gcov_events_enabled) |
70 | gcov_event(GCOV_REMOVE, info); | |
71 | } else | |
72 | prev = info; | |
73 | } | |
8cbce376 | 74 | |
2521f2c2 PO |
75 | mutex_unlock(&gcov_lock); |
76 | ||
77 | return NOTIFY_OK; | |
78 | } | |
79 | ||
80 | static struct notifier_block gcov_nb = { | |
81 | .notifier_call = gcov_module_notifier, | |
82 | }; | |
83 | ||
84 | static int __init gcov_init(void) | |
85 | { | |
86 | return register_module_notifier(&gcov_nb); | |
87 | } | |
88 | device_initcall(gcov_init); | |
89 | #endif /* CONFIG_MODULES */ |