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 */
49tnfctl_errcode_t
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*/
140tnfctl_errcode_t
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*/
274tnfctl_errcode_t
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