1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright (c) 1997-1999 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27#include <stdio.h>
28#include <fcntl.h>
29#include <ctype.h>
30#include <string.h>
31#include <signal.h>
32#include <errno.h>
33#include <stdlib.h>
34#include <stdarg.h>
35#include <unistd.h>
36#include <limits.h>
37#include <sys/types.h>
38#include <sys/stat.h>
39
40#include <libelf.h>
41#include <link.h>
42#include <elf.h>
43#include <sys/machelf.h>
44
45#include <kstat.h>
46#include <sys/cpuvar.h>
47
48typedef struct syment {
49	uintptr_t	addr;
50	char		*name;
51	size_t		size;
52} syment_t;
53
54static syment_t *symbol_table;
55static int nsyms, maxsyms;
56static char maxsymname[64];
57
58#ifdef _ELF64
59#define	elf_getshdr elf64_getshdr
60#else
61#define	elf_getshdr elf32_getshdr
62#endif
63
64static void
65add_symbol(char *name, uintptr_t addr, size_t size)
66{
67	syment_t *sep;
68
69	if (nsyms >= maxsyms) {
70		maxsyms += 10000;
71		symbol_table = realloc(symbol_table, maxsyms * sizeof (*sep));
72		if (symbol_table == NULL) {
73			(void) fprintf(stderr, "can't allocate symbol table\n");
74			exit(3);
75		}
76	}
77	sep = &symbol_table[nsyms++];
78
79	sep->name = name;
80	sep->addr = addr;
81	sep->size = size;
82}
83
84static void
85remove_symbol(uintptr_t addr)
86{
87	int i;
88	syment_t *sep = symbol_table;
89
90	for (i = 0; i < nsyms; i++, sep++)
91		if (sep->addr == addr)
92			sep->addr = 0;
93}
94
95static void
96fake_up_certain_popular_kernel_symbols(void)
97{
98	kstat_ctl_t *kc;
99	kstat_t *ksp;
100	char *name;
101
102	if ((kc = kstat_open()) == NULL)
103		return;
104
105	for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
106		if (strcmp(ksp->ks_module, "cpu_info") == 0) {
107			if ((name = malloc(20)) == NULL)
108				break;
109			/*
110			 * For consistency, keep cpu[0] and toss cpu0
111			 * or any other such symbols.
112			 */
113			if (ksp->ks_instance == 0)
114				remove_symbol((uintptr_t)ksp->ks_private);
115			(void) sprintf(name, "cpu[%d]", ksp->ks_instance);
116			add_symbol(name, (uintptr_t)ksp->ks_private,
117			    sizeof (struct cpu));
118		}
119	}
120	(void) kstat_close(kc);
121}
122
123static int
124symcmp(const void *p1, const void *p2)
125{
126	uintptr_t a1 = ((syment_t *)p1)->addr;
127	uintptr_t a2 = ((syment_t *)p2)->addr;
128
129	if (a1 < a2)
130		return (-1);
131	if (a1 > a2)
132		return (1);
133	return (0);
134}
135
136int
137symtab_init(void)
138{
139	Elf		*elf;
140	Elf_Scn		*scn = NULL;
141	Sym		*symtab, *symp, *lastsym;
142	char		*strtab;
143	uint_t		cnt;
144	int		fd;
145	int		i;
146	int		strindex = -1;
147
148	if ((fd = open("/dev/ksyms", O_RDONLY)) == -1)
149		return (-1);
150
151	(void) elf_version(EV_CURRENT);
152
153	elf = elf_begin(fd, ELF_C_READ, NULL);
154
155	for (cnt = 1; (scn = elf_nextscn(elf, scn)) != NULL; cnt++) {
156		Shdr *shdr = elf_getshdr(scn);
157		if (shdr->sh_type == SHT_SYMTAB) {
158			symtab = (Sym *)elf_getdata(scn, NULL)->d_buf;
159			nsyms = shdr->sh_size / shdr->sh_entsize;
160			strindex = shdr->sh_link;
161		}
162	}
163
164	for (cnt = 1; (scn = elf_nextscn(elf, scn)) != NULL; cnt++) {
165		if (cnt == strindex)
166			strtab = (char *)elf_getdata(scn, NULL)->d_buf;
167	}
168
169	lastsym = symtab + nsyms;
170	nsyms = 0;
171	for (symp = symtab; symp < lastsym; symp++)
172		if ((uint_t)ELF32_ST_TYPE(symp->st_info) <= STT_FUNC &&
173		    symp->st_size != 0)
174			add_symbol(symp->st_name + strtab,
175			    (uintptr_t)symp->st_value, (size_t)symp->st_size);
176
177	fake_up_certain_popular_kernel_symbols();
178	(void) sprintf(maxsymname, "0x%lx", ULONG_MAX);
179	add_symbol(maxsymname, ULONG_MAX, 1);
180
181	qsort(symbol_table, nsyms, sizeof (syment_t), symcmp);
182
183	/*
184	 * Destroy all duplicate symbols, then sort it again.
185	 */
186	for (i = 0; i < nsyms - 1; i++)
187		if (symbol_table[i].addr == symbol_table[i + 1].addr)
188			symbol_table[i].addr = 0;
189
190	qsort(symbol_table, nsyms, sizeof (syment_t), symcmp);
191
192	while (symbol_table[1].addr == 0) {
193		symbol_table++;
194		nsyms--;
195	}
196	symbol_table[0].name = "(usermode)";
197	symbol_table[0].addr = 0;
198	symbol_table[0].size = 1;
199
200	return (0);
201}
202
203char *
204addr_to_sym(uintptr_t addr, uintptr_t *offset, size_t *sizep)
205{
206	int lo = 0;
207	int hi = nsyms - 1;
208	int mid;
209	syment_t *sep;
210
211	while (hi - lo > 1) {
212		mid = (lo + hi) / 2;
213		if (addr >= symbol_table[mid].addr) {
214			lo = mid;
215		} else {
216			hi = mid;
217		}
218	}
219	sep = &symbol_table[lo];
220	*offset = addr - sep->addr;
221	*sizep = sep->size;
222	return (sep->name);
223}
224
225uintptr_t
226sym_to_addr(char *name)
227{
228	int i;
229	syment_t *sep = symbol_table;
230
231	for (i = 0; i < nsyms; i++) {
232		if (strcmp(name, sep->name) == 0)
233			return (sep->addr);
234		sep++;
235	}
236	return ((uintptr_t)NULL);
237}
238
239size_t
240sym_size(char *name)
241{
242	int i;
243	syment_t *sep = symbol_table;
244
245	for (i = 0; i < nsyms; i++) {
246		if (strcmp(name, sep->name) == 0)
247			return (sep->size);
248		sep++;
249	}
250	return (0);
251}
252