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
58 typedef struct syment {
59 uintptr_t addr;
60 char *name;
61 size_t size;
62 } syment_t;
63
64 static syment_t *symbol_table;
65 static int nsyms, maxsyms;
66 static 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
76 static void
add_symbol(char * name,uintptr_t addr,size_t size)77 add_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
96 static void
remove_symbol(uintptr_t addr)97 remove_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
108 static void
fake_up_certain_popular_kernel_symbols(void)109 fake_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 */
136 static void
fake_up_certain_popular_kernel_symbols(void)137 fake_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
154 static int
symcmp(const void * p1,const void * p2)155 symcmp(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
167 int
symtab_init(void)168 symtab_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
246 char *
addr_to_sym(uintptr_t addr,uintptr_t * offset,size_t * sizep)247 addr_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
268 uintptr_t
sym_to_addr(char * name)269 sym_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
282 size_t
sym_size(char * name)283 sym_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