xref: /freebsd/sys/gnu/gcov/gcov_subr.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019, Matthew Macy <mmacy@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/systm.h>
34 #include <sys/param.h>
35 #include <sys/sbuf.h>
36 
37 #include <sys/queue.h>
38 #include <sys/linker.h>
39 #include <sys/module.h>
40 #include <sys/eventhandler.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/syslog.h>
44 #include <sys/proc.h>
45 #include <sys/sched.h>
46 #include <sys/syslog.h>
47 #include <sys/sysctl.h>
48 #include <gnu/gcov/gcov.h>
49 #include <sys/queue.h>
50 #include "linker_if.h"
51 
52 
53 static void gcov_invoke_ctors(void);
54 static int gcov_ctors_done;
55 int gcov_events_enabled;
56 
57 static int
58 gcov_stats_reset_sysctl(SYSCTL_HANDLER_ARGS)
59 {
60 	int error, v;
61 
62 	v = 0;
63 	error = sysctl_handle_int(oidp, &v, 0, req);
64 	if (error)
65 		return (error);
66 	if (req->newptr == NULL)
67 		return (error);
68 	if (v == 0)
69 		return (0);
70 	gcov_stats_reset();
71 
72 	return (0);
73 }
74 
75 static int
76 gcov_stats_enable_sysctl(SYSCTL_HANDLER_ARGS)
77 {
78 	int error, v;
79 
80 	v = gcov_events_enabled;
81 	error = sysctl_handle_int(oidp, &v, v, req);
82 	if (error)
83 		return (error);
84 	if (req->newptr == NULL)
85 		return (error);
86 	if (v == gcov_events_enabled)
87 		return (0);
88 	//gcov_events_reset();
89 	gcov_events_enabled = !!v;
90 	if (!gcov_ctors_done)
91 		gcov_invoke_ctors();
92 	if (gcov_events_enabled)
93 		gcov_enable_events();
94 
95 	return (0);
96 }
97 
98 int
99 within_module(vm_offset_t addr, module_t mod)
100 {
101 	linker_file_t link_info;
102 	vm_offset_t mod_addr;
103 	size_t mod_size;
104 
105 	link_info = module_file(mod);
106 	mod_addr = (vm_offset_t)link_info->address;
107 	mod_size = link_info->size;
108 	if (addr >= mod_addr && addr < mod_addr + mod_size)
109 		return (1);
110 	return (0);
111 }
112 
113 
114 
115 #define GCOV_PREFIX "_GLOBAL__sub_I_65535_0_"
116 
117 static int
118 gcov_invoke_ctor(const char *name, void *arg)
119 {
120 	void (*ctor)(void);
121 	c_linker_sym_t sym;
122 	linker_symval_t symval;
123 	linker_file_t lf;
124 
125 	if (strstr(name, GCOV_PREFIX) == NULL)
126 		return (0);
127 	lf = arg;
128 	LINKER_LOOKUP_SYMBOL(lf, name, &sym);
129 	LINKER_SYMBOL_VALUES(lf, sym, &symval);
130 	ctor = (void *)symval.value;
131 	ctor();
132 	return (0);
133 }
134 
135 static int
136 gcov_invoke_lf_ctors(linker_file_t lf, void *arg __unused)
137 {
138 
139 	printf("%s processing file: %s\n", __func__, lf->filename);
140 	LINKER_EACH_FUNCTION_NAME(lf, gcov_invoke_ctor, lf);
141 	return (0);
142 }
143 
144 static void
145 gcov_invoke_ctors(void)
146 {
147 
148 	gcov_fs_init();
149 
150 	linker_file_foreach(gcov_invoke_lf_ctors, NULL);
151 	gcov_ctors_done = 1;
152 }
153 
154 static int
155 gcov_init(void *arg __unused)
156 {
157 	EVENTHANDLER_REGISTER(module_unload, gcov_module_unload, NULL, 0);
158 	gcov_enable_events();
159 	return (0);
160 }
161 
162 SYSINIT(gcov_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY, gcov_init, NULL);
163 
164 static SYSCTL_NODE(_debug, OID_AUTO, gcov, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
165     "gcov code coverage");
166 SYSCTL_PROC(_debug_gcov, OID_AUTO, reset,
167     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
168     gcov_stats_reset_sysctl, "I",
169     "Reset all profiling counts");
170 SYSCTL_PROC(_debug_gcov, OID_AUTO, enable,
171     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
172     gcov_stats_enable_sysctl, "I",
173     "Enable code coverage");
174