xref: /freebsd/sys/gnu/gcov/gcov_subr.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/types.h>
31 #include <sys/systm.h>
32 #include <sys/param.h>
33 #include <sys/sbuf.h>
34 
35 #include <sys/queue.h>
36 #include <sys/linker.h>
37 #include <sys/module.h>
38 #include <sys/eventhandler.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/syslog.h>
42 #include <sys/proc.h>
43 #include <sys/sched.h>
44 #include <sys/syslog.h>
45 #include <sys/sysctl.h>
46 #include <gnu/gcov/gcov.h>
47 #include <sys/queue.h>
48 #include "linker_if.h"
49 
50 
51 static void gcov_invoke_ctors(void);
52 static int gcov_ctors_done;
53 int gcov_events_enabled;
54 
55 static int
56 gcov_stats_reset_sysctl(SYSCTL_HANDLER_ARGS)
57 {
58 	int error, v;
59 
60 	v = 0;
61 	error = sysctl_handle_int(oidp, &v, 0, req);
62 	if (error)
63 		return (error);
64 	if (req->newptr == NULL)
65 		return (error);
66 	if (v == 0)
67 		return (0);
68 	gcov_stats_reset();
69 
70 	return (0);
71 }
72 
73 static int
74 gcov_stats_enable_sysctl(SYSCTL_HANDLER_ARGS)
75 {
76 	int error, v;
77 
78 	v = gcov_events_enabled;
79 	error = sysctl_handle_int(oidp, &v, v, req);
80 	if (error)
81 		return (error);
82 	if (req->newptr == NULL)
83 		return (error);
84 	if (v == gcov_events_enabled)
85 		return (0);
86 	//gcov_events_reset();
87 	gcov_events_enabled = !!v;
88 	if (!gcov_ctors_done)
89 		gcov_invoke_ctors();
90 	if (gcov_events_enabled)
91 		gcov_enable_events();
92 
93 	return (0);
94 }
95 
96 int
97 within_module(vm_offset_t addr, module_t mod)
98 {
99 	linker_file_t link_info;
100 	vm_offset_t mod_addr;
101 	size_t mod_size;
102 
103 	link_info = module_file(mod);
104 	mod_addr = (vm_offset_t)link_info->address;
105 	mod_size = link_info->size;
106 	if (addr >= mod_addr && addr < mod_addr + mod_size)
107 		return (1);
108 	return (0);
109 }
110 
111 
112 
113 #define GCOV_PREFIX "_GLOBAL__sub_I_65535_0_"
114 
115 static int
116 gcov_invoke_ctor(const char *name, void *arg)
117 {
118 	void (*ctor)(void);
119 	c_linker_sym_t sym;
120 	linker_symval_t symval;
121 	linker_file_t lf;
122 
123 	if (strstr(name, GCOV_PREFIX) == NULL)
124 		return (0);
125 	lf = arg;
126 	LINKER_LOOKUP_SYMBOL(lf, name, &sym);
127 	LINKER_SYMBOL_VALUES(lf, sym, &symval);
128 	ctor = (void *)symval.value;
129 	ctor();
130 	return (0);
131 }
132 
133 static int
134 gcov_invoke_lf_ctors(linker_file_t lf, void *arg __unused)
135 {
136 
137 	printf("%s processing file: %s\n", __func__, lf->filename);
138 	LINKER_EACH_FUNCTION_NAME(lf, gcov_invoke_ctor, lf);
139 	return (0);
140 }
141 
142 static void
143 gcov_invoke_ctors(void)
144 {
145 
146 	gcov_fs_init();
147 
148 	linker_file_foreach(gcov_invoke_lf_ctors, NULL);
149 	gcov_ctors_done = 1;
150 }
151 
152 static int
153 gcov_init(void *arg __unused)
154 {
155 	EVENTHANDLER_REGISTER(module_unload, gcov_module_unload, NULL, 0);
156 	gcov_enable_events();
157 	return (0);
158 }
159 
160 SYSINIT(gcov_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY, gcov_init, NULL);
161 
162 static SYSCTL_NODE(_debug, OID_AUTO, gcov, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
163     "gcov code coverage");
164 SYSCTL_PROC(_debug_gcov, OID_AUTO, reset,
165     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
166     gcov_stats_reset_sysctl, "I",
167     "Reset all profiling counts");
168 SYSCTL_PROC(_debug_gcov, OID_AUTO, enable,
169     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0,
170     gcov_stats_enable_sysctl, "I",
171     "Enable code coverage");
172