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#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29#include <stdio.h>
30#include <fcntl.h>
31#include <ctype.h>
32#include <string.h>
33#include <signal.h>
34#include <errno.h>
35#include <stdlib.h>
36#include <stdarg.h>
37#include <unistd.h>
38#include <limits.h>
39#include <sys/types.h>
40#include <sys/stat.h>
41
42#include <libelf.h>
43#include <link.h>
44#include <elf.h>
45#include <gelf.h>
46#ifdef illumos
47#include <sys/machelf.h>
48
49#include <kstat.h>
50#else
51#include <sys/elf.h>
52#include <sys/param.h>
53#include <sys/module.h>
54#include <sys/linker.h>
55#endif
56#include <sys/cpuvar.h>
57
58typedef struct syment {
59	uintptr_t	addr;
60	char		*name;
61	size_t		size;
62} syment_t;
63
64static syment_t *symbol_table;
65static int nsyms, maxsyms;
66static char maxsymname[64];
67
68#ifdef illumos
69#ifdef _ELF64
70#define	elf_getshdr elf64_getshdr
71#else
72#define	elf_getshdr elf32_getshdr
73#endif
74#endif
75
76static void
77add_symbol(char *name, uintptr_t addr, size_t size)
78{
79	syment_t *sep;
80
81	if (nsyms >= maxsyms) {
82		maxsyms += 10000;
83		symbol_table = realloc(symbol_table, maxsyms * sizeof (*sep));
84		if (symbol_table == NULL) {
85			(void) fprintf(stderr, "can't allocate symbol table\n");
86			exit(3);
87		}
88	}
89	sep = &symbol_table[nsyms++];
90
91	sep->name = name;
92	sep->addr = addr;
93	sep->size = size;
94}
95
96static void
97remove_symbol(uintptr_t addr)
98{
99	int i;
100	syment_t *sep = symbol_table;
101
102	for (i = 0; i < nsyms; i++, sep++)
103		if (sep->addr == addr)
104			sep->addr = 0;
105}
106
107#ifdef illumos
108static void
109fake_up_certain_popular_kernel_symbols(void)
110{
111	kstat_ctl_t *kc;
112	kstat_t *ksp;
113	char *name;
114
115	if ((kc = kstat_open()) == NULL)
116		return;
117
118	for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
119		if (strcmp(ksp->ks_module, "cpu_info") == 0) {
120			if ((name = malloc(20)) == NULL)
121				break;
122			/*
123			 * For consistency, keep cpu[0] and toss cpu0
124			 * or any other such symbols.
125			 */
126			if (ksp->ks_instance == 0)
127				remove_symbol((uintptr_t)ksp->ks_private);
128			(void) sprintf(name, "cpu[%d]", ksp->ks_instance);
129			add_symbol(name, (uintptr_t)ksp->ks_private,
130			    sizeof (struct cpu));
131		}
132	}
133	(void) kstat_close(kc);
134}
135#else /* !illumos */
136static void
137fake_up_certain_popular_kernel_symbols(void)
138{
139	char *name;
140	uintptr_t addr;
141	int i;
142
143	/* Good for up to 256 CPUs */
144	for(i=0; i < 256;  i++) {
145		if ((name = malloc(20)) == NULL)
146			break;
147		(void) sprintf(name, "cpu[%d]", i);
148		addr = 0x01000000 + (i << 16);
149		add_symbol(name, addr, sizeof (uintptr_t));
150	}
151}
152#endif /* illumos */
153
154static int
155symcmp(const void *p1, const void *p2)
156{
157	uintptr_t a1 = ((syment_t *)p1)->addr;
158	uintptr_t a2 = ((syment_t *)p2)->addr;
159
160	if (a1 < a2)
161		return (-1);
162	if (a1 > a2)
163		return (1);
164	return (0);
165}
166
167int
168symtab_init(void)
169{
170	Elf		*elf;
171	Elf_Scn		*scn = NULL;
172	GElf_Sym	*symtab, *symp, *lastsym;
173	char		*strtab;
174	uint_t		cnt;
175	int		fd;
176	int		i;
177	int		strindex = -1;
178
179#ifndef illumos
180	if ((fd = open("/dev/ksyms", O_RDONLY)) == -1) {
181		if (errno == ENOENT && modfind("ksyms") == -1) {
182			kldload("ksyms");
183			fd = open("/dev/ksyms", O_RDONLY);
184		}
185		if (fd == -1)
186			return (-1);
187	}
188#else
189	if ((fd = open("/dev/ksyms", O_RDONLY)) == -1)
190		return (-1);
191#endif
192
193	(void) elf_version(EV_CURRENT);
194
195	elf = elf_begin(fd, ELF_C_READ, NULL);
196	for (cnt = 1; (scn = elf_nextscn(elf, scn)) != NULL; cnt++) {
197		GElf_Shdr shdr;
198		(void) gelf_getshdr(scn, &shdr);
199		if (shdr.sh_type == SHT_SYMTAB) {
200			symtab = (GElf_Sym *)elf_getdata(scn, NULL)->d_buf;
201			nsyms = shdr.sh_size / shdr.sh_entsize;
202			strindex = shdr.sh_link;
203		}
204	}
205
206	for (cnt = 1; (scn = elf_nextscn(elf, scn)) != NULL; cnt++) {
207		if (cnt == strindex)
208			strtab = (char *)elf_getdata(scn, NULL)->d_buf;
209	}
210
211	lastsym = symtab + nsyms;
212	nsyms = 0;
213	for (symp = symtab; symp < lastsym; symp++)
214		if ((uint_t)ELF32_ST_TYPE(symp->st_info) <= STT_FUNC &&
215		    symp->st_size != 0)
216			add_symbol(symp->st_name + strtab,
217			    (uintptr_t)symp->st_value, (size_t)symp->st_size);
218
219	fake_up_certain_popular_kernel_symbols();
220	(void) sprintf(maxsymname, "0x%lx", ULONG_MAX);
221	add_symbol(maxsymname, ULONG_MAX, 1);
222
223	qsort(symbol_table, nsyms, sizeof (syment_t), symcmp);
224
225	/*
226	 * Destroy all duplicate symbols, then sort it again.
227	 */
228	for (i = 0; i < nsyms - 1; i++)
229		if (symbol_table[i].addr == symbol_table[i + 1].addr)
230			symbol_table[i].addr = 0;
231
232	qsort(symbol_table, nsyms, sizeof (syment_t), symcmp);
233
234	while (symbol_table[1].addr == 0) {
235		symbol_table++;
236		nsyms--;
237	}
238	symbol_table[0].name = "(usermode)";
239	symbol_table[0].addr = 0;
240	symbol_table[0].size = 1;
241
242	close(fd);
243	return (0);
244}
245
246char *
247addr_to_sym(uintptr_t addr, uintptr_t *offset, size_t *sizep)
248{
249	int lo = 0;
250	int hi = nsyms - 1;
251	int mid;
252	syment_t *sep;
253
254	while (hi - lo > 1) {
255		mid = (lo + hi) / 2;
256		if (addr >= symbol_table[mid].addr) {
257			lo = mid;
258		} else {
259			hi = mid;
260		}
261	}
262	sep = &symbol_table[lo];
263	*offset = addr - sep->addr;
264	*sizep = sep->size;
265	return (sep->name);
266}
267
268uintptr_t
269sym_to_addr(char *name)
270{
271	int i;
272	syment_t *sep = symbol_table;
273
274	for (i = 0; i < nsyms; i++) {
275		if (strcmp(name, sep->name) == 0)
276			return (sep->addr);
277		sep++;
278	}
279	return (0);
280}
281
282size_t
283sym_size(char *name)
284{
285	int i;
286	syment_t *sep = symbol_table;
287
288	for (i = 0; i < nsyms; i++) {
289		if (strcmp(name, sep->name) == 0)
290			return (sep->size);
291		sep++;
292	}
293	return (0);
294}
295