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) 1994, by Sun Microsytems, Inc.
24 */
25
26 #pragma ident "%Z%%M% %I% %E% SMI"
27
28 /*
29 * Generic functions that know how to traverse elf sections in an object.
30 * Also functions that know how to traverse records in a section.
31 *
32 */
33
34 #include <string.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 #include <errno.h>
38 #include <sys/procfs.h>
39 #include <sys/stat.h>
40
41 #include "tnfctl_int.h"
42 #include "dbg.h"
43
44
45 /*
46 * _tnfctl_traverse_object() - traverses all of the elf sections in an object,
47 * calling the supplied function on each.
48 */
49 tnfctl_errcode_t
_tnfctl_traverse_object(int objfd,uintptr_t addr,tnfctl_elf_search_t * search_info_p)50 _tnfctl_traverse_object(int objfd, uintptr_t addr,
51 tnfctl_elf_search_t *search_info_p)
52 {
53 Elf *elf;
54 GElf_Ehdr *ehdr, ehdr_obj;
55 char *strs;
56 GElf_Shdr *shdr, shdr_obj;
57 Elf_Data *data;
58 u_int idx;
59 tnfctl_errcode_t prexstat = TNFCTL_ERR_NONE;
60
61 DBG_TNF_PROBE_1(_tnfctl_traverse_object_1, "libtnfctl",
62 "sunw%verbosity 3",
63 tnf_opaque, obj_addr, addr);
64
65 if (elf_version(EV_CURRENT) == EV_NONE)
66 return (TNFCTL_ERR_INTERNAL);
67
68 /* open elf descriptor on the fd */
69 elf = elf_begin(objfd, ELF_C_READ, NULL);
70 if (elf == NULL || elf_kind(elf) != ELF_K_ELF) {
71 DBG_TNF_PROBE_0(_tnfctl_traverse_object_2, "libtnfctl",
72 "sunw%verbosity 3; sunw%debug 'not elf object'");
73 return (TNFCTL_ERR_INTERNAL);
74 }
75 /* get the elf header */
76 if ((ehdr = gelf_getehdr(elf, &ehdr_obj)) == NULL) {
77 DBG((void) fprintf(stderr,
78 "_tnfctl_traverse_object: gelf_getehdr failed\n"));
79 (void) elf_end(elf);
80 return (TNFCTL_ERR_INTERNAL);
81 }
82 if ((ehdr->e_type != ET_EXEC) && (ehdr->e_type != ET_DYN)) {
83 DBG((void) fprintf(stderr,
84 "_tnfctl_traverse_object: not an "
85 "executable or a shared object\n"));
86 (void) elf_end(elf);
87 return (TNFCTL_ERR_INTERNAL);
88 }
89 /* if an executable file, the base address is 0 */
90 if (ehdr->e_type == ET_EXEC)
91 addr = 0;
92 /* get a pointer to the elf header string table */
93 strs = elf_strptr(elf, ehdr->e_shstrndx, NULL);
94
95 DBG_TNF_PROBE_1(_tnfctl_traverse_object_3, "libtnfctl",
96 "sunw%verbosity 3",
97 tnf_long, num_sections_found, ehdr->e_shnum);
98
99 for (idx = 1; idx < ehdr->e_shnum; idx++) {
100 Elf_Scn *scn;
101
102 if ((scn = elf_getscn(elf, idx)) == NULL) {
103 DBG((void) fprintf(stderr,
104 "_tnfctl_traverse_object: elf_getscn failed\n"));
105 prexstat = TNFCTL_ERR_INTERNAL;
106 break;
107 }
108 if ((shdr = gelf_getshdr(scn, &shdr_obj)) == NULL) {
109 DBG((void) fprintf(stderr,
110 "_tnfctl_traverse_obj:gelf_getshdr failed\n"));
111 prexstat = TNFCTL_ERR_INTERNAL;
112 break;
113 }
114
115 if ((data = elf_getdata(scn, NULL)) == NULL) {
116 DBG((void) fprintf(stderr,
117 "_tnfctl_traverse_obj:gelf_getdata failed\n"));
118 prexstat = TNFCTL_ERR_INTERNAL;
119 break;
120 }
121 /* call the supplied function */
122 prexstat = search_info_p->section_func(elf,
123 strs, scn, shdr, data, addr, search_info_p);
124 if (prexstat)
125 break;
126 }
127
128 (void) elf_end(elf);
129
130 return (prexstat);
131
132 } /* end _tnfctl_traverse_object */
133
134
135 /*
136 * _tnfctl_traverse_rela() - this function traverses a .rela section calling the
137 * supplied function on each relocation record.
138 */
139 /*ARGSUSED*/
140 tnfctl_errcode_t
_tnfctl_traverse_rela(Elf * elf,char * strs,Elf_Scn * rel_scn,GElf_Shdr * rel_shdr,Elf_Data * rel_data,uintptr_t baseaddr,tnfctl_elf_search_t * search_info_p)141 _tnfctl_traverse_rela(Elf * elf, char *strs, Elf_Scn * rel_scn,
142 GElf_Shdr * rel_shdr, Elf_Data * rel_data, uintptr_t baseaddr,
143 tnfctl_elf_search_t * search_info_p)
144 {
145 Elf_Scn *sym_scn;
146 GElf_Shdr *sym_shdr, sym_shdr_obj;
147 Elf_Data *sym_data;
148 Elf3264_Sym *sym_table;
149 Elf_Scn *str_scn;
150 GElf_Shdr *str_shdr, str_shdr_obj;
151 Elf_Data *str_data;
152 char *str_table;
153 ulong_t nrels;
154 uint_t i;
155 boolean_t isrela;
156 size_t rela_sz;
157 char *ptr;
158
159 DBG_TNF_PROBE_0(_tnfctl_traverse_rela_1, "libtnfctl",
160 "sunw%verbosity 4");
161
162 /* bail if this isn't a rela (or rel) section */
163 if (rel_shdr->sh_type == SHT_RELA) {
164 isrela = B_TRUE;
165 } else if (rel_shdr->sh_type == SHT_REL) {
166 isrela = B_FALSE;
167 } else
168 return (TNFCTL_ERR_NONE);
169
170 /* find the symbol table section associated with this rela section */
171 sym_scn = elf_getscn(elf, rel_shdr->sh_link);
172 if (sym_scn == NULL) {
173 DBG((void) fprintf(stderr,
174 "_tnfctl_traverse_rela:elf_getscn (sym) failed\n"));
175 return (TNFCTL_ERR_INTERNAL);
176 }
177 sym_shdr = gelf_getshdr(sym_scn, &sym_shdr_obj);
178 if (sym_shdr == NULL) {
179 DBG((void) fprintf(stderr,
180 "_tnfctl_traverse_rela:gelf_getshdr (sym) failed\n"));
181 return (TNFCTL_ERR_INTERNAL);
182 }
183 sym_data = elf_getdata(sym_scn, NULL);
184 if (sym_data == NULL) {
185 DBG((void) fprintf(stderr,
186 "_tnfctl_traverse_rela:elf_getdata (sym) failed\n"));
187 return (TNFCTL_ERR_INTERNAL);
188 }
189 sym_table = (Elf3264_Sym *) sym_data->d_buf;
190
191 /* find the string table associated with the symbol table */
192 str_scn = elf_getscn(elf, sym_shdr->sh_link);
193 if (str_scn == NULL) {
194 DBG((void) fprintf(stderr,
195 "_tnfctl_traverse_rela:elf_getscn (str) failed\n"));
196 return (TNFCTL_ERR_INTERNAL);
197 }
198 str_shdr = gelf_getshdr(str_scn, &str_shdr_obj);
199 if (str_shdr == NULL) {
200 DBG((void) fprintf(stderr,
201 "_tnfctl_traverse_rela:gelf_getshdr (str) failed\n"));
202 return (TNFCTL_ERR_INTERNAL);
203 }
204 str_data = elf_getdata(str_scn, NULL);
205 if (str_data == NULL) {
206 DBG((void) fprintf(stderr,
207 "_tnfctl_traverse_rela: elf_getdata (str) failed\n"));
208 return (TNFCTL_ERR_INTERNAL);
209 }
210 str_table = (char *) str_data->d_buf;
211
212 /* loop over each relocation record */
213 nrels = rel_shdr->sh_size / rel_shdr->sh_entsize;
214
215 DBG_TNF_PROBE_1(_tnfctl_traverse_rela_2, "libtnfctl",
216 "sunw%verbosity 3",
217 tnf_long, relocations_found, nrels);
218
219 ptr = rel_data->d_buf;
220 rela_sz = (isrela) ? sizeof (Elf3264_Rela) : sizeof (Elf3264_Rel);
221 for (i = 0; i < nrels; i++, ptr += rela_sz) {
222 Elf3264_Word syminfo;
223 Elf3264_Sym *sym;
224 Elf3264_Addr offset;
225 char *name;
226 uintptr_t addr;
227 tnfctl_errcode_t prexstat;
228
229 /* decode the r_info field of the relocation record */
230 if (isrela) {
231 Elf3264_Rela *rela_p;
232
233 /*LINTED pointer cast may result in improper alignment*/
234 rela_p = (Elf3264_Rela *) ptr;
235 syminfo = ELF3264_R_SYM(rela_p->r_info);
236 offset = rela_p->r_offset;
237 } else {
238 Elf3264_Rel *rel_p;
239
240 /*LINTED pointer cast may result in improper alignment*/
241 rel_p = (Elf3264_Rel *) ptr;
242 syminfo = ELF3264_R_SYM(rel_p->r_info);
243 offset = rel_p->r_offset;
244 }
245
246 /* find the associated symbol table entry */
247 if (!syminfo)
248 continue;
249 sym = sym_table + syminfo;
250
251 /* find the associated string table entry */
252 if (!sym->st_name)
253 continue;
254 name = str_table + sym->st_name;
255 addr = offset + baseaddr;
256
257 prexstat = search_info_p->record_func(name, addr, ptr,
258 search_info_p);
259 if (prexstat)
260 break;
261 }
262
263 return (TNFCTL_ERR_NONE);
264
265 } /* end _tnfctl_traverse_rela */
266
267
268 /*
269 * _tnfctl_traverse_dynsym() - this function traverses a dynsym section calling
270 * the supplied function on each symbol.
271 */
272
273 /*ARGSUSED*/
274 tnfctl_errcode_t
_tnfctl_traverse_dynsym(Elf * elf,char * elfstrs,Elf_Scn * scn,GElf_Shdr * shdr,Elf_Data * data,uintptr_t baseaddr,tnfctl_elf_search_t * search_info_p)275 _tnfctl_traverse_dynsym(Elf * elf,
276 char *elfstrs,
277 Elf_Scn * scn,
278 GElf_Shdr * shdr,
279 Elf_Data * data,
280 uintptr_t baseaddr,
281 tnfctl_elf_search_t * search_info_p)
282 {
283 ulong_t nsyms;
284 int i;
285 char *strs;
286 tnfctl_errcode_t prexstat;
287
288 Elf3264_Sym *syms;
289
290 /* bail if this isn't a dynsym section */
291 if (shdr->sh_type != SHT_DYNSYM)
292 return (TNFCTL_ERR_NONE);
293 #if 0
294 printf("### entering _tnfctl_traverse_dynsym...\n");
295 #endif
296 syms = data->d_buf;
297 nsyms = shdr->sh_size / shdr->sh_entsize;
298 strs = elf_strptr(elf, shdr->sh_link, 0);
299
300 DBG_TNF_PROBE_1(_tnfctl_traverse_dynsym_1, "libtnfctl",
301 "sunw%verbosity 3",
302 tnf_long, symbols_found, nsyms);
303
304 for (i = 0; i < nsyms; i++) {
305 Elf3264_Sym *sym = &syms[i];
306 char *name;
307 uintptr_t addr;
308
309 name = strs + sym->st_name;
310 addr = baseaddr + sym->st_value;
311
312 #if 0
313 if (name != 0)
314 printf("_tnfctl_traverse_dynsym: name = %s\n", name);
315 else
316 printf("_tnfctl_traverse_dynsym: name is 0\n");
317 #endif
318 prexstat = search_info_p->record_func(name,
319 addr, sym, search_info_p);
320 if (prexstat)
321 break;
322 }
323 #if 0
324 printf("### leaving _tnfctl_traverse_dynsym...\n");
325 #endif
326 return (prexstat);
327
328 } /* end _tnfctl_traverse_dynsym */
329