libdwarf_info.c revision 1.2.8.2
1/*	$NetBSD: libdwarf_info.c,v 1.2.8.2 2014/08/19 23:46:44 tls Exp $	*/
2
3/*-
4 * Copyright (c) 2007 John Birrell (jb@freebsd.org)
5 * Copyright (c) 2010,2011 Kai Wang
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include "_libdwarf.h"
31
32__RCSID("$NetBSD: libdwarf_info.c,v 1.2.8.2 2014/08/19 23:46:44 tls Exp $");
33ELFTC_VCSID("Id: libdwarf_info.c 2942 2013-05-04 23:03:54Z kaiwang27 ");
34
35int
36_dwarf_info_first_cu(Dwarf_Debug dbg, Dwarf_Error *error)
37{
38	Dwarf_CU cu;
39	int ret;
40
41	assert(dbg->dbg_cu_current == NULL);
42	cu = STAILQ_FIRST(&dbg->dbg_cu);
43	if (cu != NULL) {
44		dbg->dbg_cu_current = cu;
45		return (DW_DLE_NONE);
46	}
47
48	if (dbg->dbg_info_loaded)
49		return (DW_DLE_NO_ENTRY);
50
51	dbg->dbg_info_off = 0;
52	ret = _dwarf_info_load(dbg, 0, error);
53	if (ret != DW_DLE_NONE)
54		return (ret);
55
56	dbg->dbg_cu_current = STAILQ_FIRST(&dbg->dbg_cu);
57
58	return (DW_DLE_NONE);
59}
60
61int
62_dwarf_info_next_cu(Dwarf_Debug dbg, Dwarf_Error *error)
63{
64	Dwarf_CU cu;
65	int ret;
66
67	assert(dbg->dbg_cu_current != NULL);
68	cu = STAILQ_NEXT(dbg->dbg_cu_current, cu_next);
69	if (cu != NULL) {
70		dbg->dbg_cu_current = cu;
71		return (DW_DLE_NONE);
72	}
73
74	if (dbg->dbg_info_loaded) {
75		dbg->dbg_cu_current = NULL;
76		return (DW_DLE_NO_ENTRY);
77	}
78
79	ret = _dwarf_info_load(dbg, 0, error);
80	if (ret != DW_DLE_NONE)
81		return (ret);
82
83	dbg->dbg_cu_current = STAILQ_NEXT(dbg->dbg_cu_current, cu_next);
84
85	return (DW_DLE_NONE);
86}
87
88int
89_dwarf_info_load(Dwarf_Debug dbg, int load_all, Dwarf_Error *error)
90{
91	Dwarf_CU cu;
92	Dwarf_Section *ds;
93	int dwarf_size, ret;
94	uint64_t length;
95	uint64_t next_offset;
96	uint64_t offset;
97
98	ret = DW_DLE_NONE;
99	if (dbg->dbg_info_loaded)
100		return (DW_DLE_NONE);
101
102	offset = dbg->dbg_info_off;
103	ds = dbg->dbg_info_sec;
104	assert(ds != NULL);
105	while (offset < ds->ds_size) {
106		if ((cu = calloc(1, sizeof(struct _Dwarf_CU))) == NULL) {
107			DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
108			return (DW_DLE_MEMORY);
109		}
110
111		cu->cu_dbg = dbg;
112		cu->cu_offset = offset;
113
114		length = dbg->read(ds->ds_data, &offset, 4);
115		if (length == 0xffffffff) {
116			length = dbg->read(ds->ds_data, &offset, 8);
117			dwarf_size = 8;
118		} else
119			dwarf_size = 4;
120		cu->cu_dwarf_size = dwarf_size;
121
122		/*
123		 * Check if there is enough ELF data for this CU. This assumes
124		 * that libelf gives us the entire section in one Elf_Data
125		 * object.
126		 */
127		if (length > ds->ds_size - offset) {
128			free(cu);
129			DWARF_SET_ERROR(dbg, error, DW_DLE_CU_LENGTH_ERROR);
130			return (DW_DLE_CU_LENGTH_ERROR);
131		}
132
133		/* Compute the offset to the next compilation unit: */
134		next_offset = offset + length;
135		dbg->dbg_info_off = next_offset;
136
137		/* Initialise the compilation unit. */
138		cu->cu_length		 = length;
139		cu->cu_length_size	 = (dwarf_size == 4 ? 4 : 12);
140		cu->cu_version		 = dbg->read(ds->ds_data, &offset, 2);
141		cu->cu_abbrev_offset	 = dbg->read(ds->ds_data, &offset,
142		    dwarf_size);
143		cu->cu_abbrev_offset_cur = cu->cu_abbrev_offset;
144		cu->cu_pointer_size	 = dbg->read(ds->ds_data, &offset, 1);
145		cu->cu_next_offset	 = next_offset;
146
147		/* Add the compilation unit to the list. */
148		STAILQ_INSERT_TAIL(&dbg->dbg_cu, cu, cu_next);
149
150		if (cu->cu_version < 2 || cu->cu_version > 4) {
151			DWARF_SET_ERROR(dbg, error, DW_DLE_VERSION_STAMP_ERROR);
152			ret = DW_DLE_VERSION_STAMP_ERROR;
153			break;
154		}
155
156		cu->cu_1st_offset = offset;
157
158		offset = next_offset;
159
160		if (!load_all)
161			break;
162	}
163
164	if ((Dwarf_Unsigned) dbg->dbg_info_off >= ds->ds_size)
165		dbg->dbg_info_loaded = 1;
166
167	return (ret);
168}
169
170void
171_dwarf_info_cleanup(Dwarf_Debug dbg)
172{
173	Dwarf_CU cu, tcu;
174
175	assert(dbg != NULL && dbg->dbg_mode == DW_DLC_READ);
176
177	STAILQ_FOREACH_SAFE(cu, &dbg->dbg_cu, cu_next, tcu) {
178		STAILQ_REMOVE(&dbg->dbg_cu, cu, _Dwarf_CU, cu_next);
179		_dwarf_abbrev_cleanup(cu);
180		if (cu->cu_lineinfo != NULL) {
181			_dwarf_lineno_cleanup(cu->cu_lineinfo);
182			cu->cu_lineinfo = NULL;
183		}
184		free(cu);
185	}
186}
187
188int
189_dwarf_info_gen(Dwarf_P_Debug dbg, Dwarf_Error *error)
190{
191	Dwarf_P_Section ds;
192	Dwarf_Rel_Section drs;
193	Dwarf_Unsigned offset;
194	Dwarf_CU cu;
195	int ret;
196
197	assert(dbg != NULL && dbg->write_alloc != NULL);
198
199	if (dbg->dbgp_root_die == NULL)
200		return (DW_DLE_NONE);
201
202	/* Create the single CU for this debugging object. */
203	if ((cu = calloc(1, sizeof(struct _Dwarf_CU))) == NULL) {
204		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
205		return (DW_DLE_MEMORY);
206	}
207	cu->cu_dbg = dbg;
208	cu->cu_version = 2;	/* DWARF2 */
209	cu->cu_pointer_size = dbg->dbg_pointer_size;
210	STAILQ_INSERT_TAIL(&dbg->dbg_cu, cu, cu_next);
211
212	/* Create .debug_info section. */
213	if ((ret = _dwarf_section_init(dbg, &dbg->dbgp_info, ".debug_info", 0,
214	    error)) != DW_DLE_NONE)
215		goto gen_fail1;
216	ds = dbg->dbgp_info;
217
218	/* Create relocation section for .debug_init */
219	if ((ret = _dwarf_reloc_section_init(dbg, &drs, ds, error)) !=
220	    DW_DLE_NONE)
221		goto gen_fail0;
222
223	/* Length placeholder. (We only use 32-bit DWARF format) */
224	RCHECK(WRITE_VALUE(cu->cu_length, 4));
225
226	/* Write CU version */
227	RCHECK(WRITE_VALUE(cu->cu_version, 2));
228
229	/*
230	 * Write abbrev offset. (always 0, we only support single CU)
231	 * Also generate a relocation entry for this offset.
232	 */
233	RCHECK(_dwarf_reloc_entry_add(dbg, drs, ds, dwarf_drt_data_reloc, 4,
234	    ds->ds_size, 0, cu->cu_abbrev_offset, ".debug_abbrev", error));
235
236	/* Pointer size. */
237	RCHECK(WRITE_VALUE(cu->cu_pointer_size, 1));
238
239	/* Transform the DIE(s) of this CU. */
240	RCHECK(_dwarf_die_gen(dbg, cu, drs, error));
241
242	/* Now we can fill in the length of this CU. */
243	cu->cu_length = ds->ds_size - 4;
244	offset = 0;
245	dbg->write(ds->ds_data, &offset, cu->cu_length, 4);
246
247	/* Inform application the creation of .debug_info ELF section. */
248	RCHECK(_dwarf_section_callback(dbg, ds, SHT_PROGBITS, 0, 0, 0, error));
249
250	/*
251	 * Inform application the creation of relocation section for
252	 * .debug_info.
253	 */
254	RCHECK(_dwarf_reloc_section_finalize(dbg, drs, error));
255
256	return (DW_DLE_NONE);
257
258gen_fail:
259	_dwarf_reloc_section_free(dbg, &drs);
260
261gen_fail0:
262	_dwarf_section_free(dbg, &dbg->dbgp_info);
263
264gen_fail1:
265	STAILQ_REMOVE(&dbg->dbg_cu, cu, _Dwarf_CU, cu_next);
266	free(cu);
267
268	return (ret);
269}
270
271void
272_dwarf_info_pro_cleanup(Dwarf_P_Debug dbg)
273{
274	Dwarf_CU cu;
275
276	assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
277
278	cu = STAILQ_FIRST(&dbg->dbg_cu);
279	if (cu != NULL) {
280		STAILQ_REMOVE(&dbg->dbg_cu, cu, _Dwarf_CU, cu_next);
281		_dwarf_abbrev_cleanup(cu);
282		free(cu);
283	}
284}
285