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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 | ||
7a1d55b9 JB |
52 | /** |
53 | * store_gcov_u32 - store 32 bit number in gcov format to buffer | |
54 | * @buffer: target buffer or NULL | |
55 | * @off: offset into the buffer | |
56 | * @v: value to be stored | |
57 | * | |
58 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
59 | * unsigned binary form of the endianness of the machine generating the | |
60 | * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't | |
61 | * store anything. | |
62 | */ | |
63 | size_t store_gcov_u32(void *buffer, size_t off, u32 v) | |
64 | { | |
65 | u32 *data; | |
66 | ||
67 | if (buffer) { | |
68 | data = buffer + off; | |
69 | *data = v; | |
70 | } | |
71 | ||
72 | return sizeof(*data); | |
73 | } | |
74 | ||
75 | /** | |
76 | * store_gcov_u64 - store 64 bit number in gcov format to buffer | |
77 | * @buffer: target buffer or NULL | |
78 | * @off: offset into the buffer | |
79 | * @v: value to be stored | |
80 | * | |
81 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
82 | * unsigned binary form of the endianness of the machine generating the | |
83 | * file. 64 bit numbers are stored as two 32 bit numbers, the low part | |
84 | * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store | |
85 | * anything. | |
86 | */ | |
87 | size_t store_gcov_u64(void *buffer, size_t off, u64 v) | |
88 | { | |
89 | u32 *data; | |
90 | ||
91 | if (buffer) { | |
92 | data = buffer + off; | |
93 | ||
94 | data[0] = (v & 0xffffffffUL); | |
95 | data[1] = (v >> 32); | |
96 | } | |
97 | ||
98 | return sizeof(*data) * 2; | |
99 | } | |
100 | ||
2521f2c2 | 101 | #ifdef CONFIG_MODULES |
2521f2c2 PO |
102 | /* Update list and generate events when modules are unloaded. */ |
103 | static int gcov_module_notifier(struct notifier_block *nb, unsigned long event, | |
104 | void *data) | |
105 | { | |
106 | struct module *mod = data; | |
8cbce376 FH |
107 | struct gcov_info *info = NULL; |
108 | struct gcov_info *prev = NULL; | |
2521f2c2 PO |
109 | |
110 | if (event != MODULE_STATE_GOING) | |
111 | return NOTIFY_OK; | |
112 | mutex_lock(&gcov_lock); | |
8cbce376 | 113 | |
2521f2c2 | 114 | /* Remove entries located in module from linked list. */ |
8cbce376 | 115 | while ((info = gcov_info_next(info))) { |
e178a5be | 116 | if (gcov_info_within_module(info, mod)) { |
8cbce376 | 117 | gcov_info_unlink(prev, info); |
2521f2c2 PO |
118 | if (gcov_events_enabled) |
119 | gcov_event(GCOV_REMOVE, info); | |
120 | } else | |
121 | prev = info; | |
122 | } | |
8cbce376 | 123 | |
2521f2c2 PO |
124 | mutex_unlock(&gcov_lock); |
125 | ||
126 | return NOTIFY_OK; | |
127 | } | |
128 | ||
129 | static struct notifier_block gcov_nb = { | |
130 | .notifier_call = gcov_module_notifier, | |
131 | }; | |
132 | ||
133 | static int __init gcov_init(void) | |
134 | { | |
135 | return register_module_notifier(&gcov_nb); | |
136 | } | |
137 | device_initcall(gcov_init); | |
138 | #endif /* CONFIG_MODULES */ |