xref: /freebsd/contrib/elftoolchain/libdwarf/libdwarf_loclist.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 2009,2011 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include "_libdwarf.h"
28 
29 ELFTC_VCSID("$Id: libdwarf_loclist.c 3061 2014-06-02 00:42:41Z kaiwang27 $");
30 
31 static int
32 _dwarf_loclist_add_locdesc(Dwarf_Debug dbg, Dwarf_CU cu, Dwarf_Section *ds,
33     Dwarf_Unsigned *off, Dwarf_Locdesc **ld, Dwarf_Signed *ldlen,
34     Dwarf_Unsigned *total_len, Dwarf_Error *error)
35 {
36 	uint64_t start, end;
37 	int i, len, ret;
38 
39 	if (total_len != NULL)
40 		*total_len = 0;
41 
42 	for (i = 0; *off < ds->ds_size; i++) {
43 		start = dbg->read(ds->ds_data, off, cu->cu_pointer_size);
44 		end = dbg->read(ds->ds_data, off, cu->cu_pointer_size);
45 		if (ld != NULL) {
46 			ld[i]->ld_lopc = start;
47 			ld[i]->ld_hipc = end;
48 		}
49 
50 		if (total_len != NULL)
51 			*total_len += 2 * cu->cu_pointer_size;
52 
53 		/* Check if it is the end entry. */
54 		if (start == 0 && end ==0) {
55 			i++;
56 			break;
57 		}
58 
59 		/* Check if it is base-select entry. */
60 		if ((cu->cu_pointer_size == 4 && start == ~0U) ||
61 		    (cu->cu_pointer_size == 8 && start == ~0ULL))
62 			continue;
63 
64 		/* Otherwise it's normal entry. */
65 		len = dbg->read(ds->ds_data, off, 2);
66 		if (*off + len > ds->ds_size) {
67 			DWARF_SET_ERROR(dbg, error,
68 			    DW_DLE_DEBUG_LOC_SECTION_SHORT);
69 			return (DW_DLE_DEBUG_LOC_SECTION_SHORT);
70 		}
71 
72 		if (total_len != NULL)
73 			*total_len += len;
74 
75 		if (ld != NULL) {
76 			ret = _dwarf_loc_fill_locdesc(dbg, ld[i],
77 			    ds->ds_data + *off, len, cu->cu_pointer_size,
78 			    cu->cu_length_size == 4 ? 4 : 8, cu->cu_version,
79 			    error);
80 			if (ret != DW_DLE_NONE)
81 				return (ret);
82 		}
83 
84 		*off += len;
85 	}
86 
87 	if (ldlen != NULL)
88 		*ldlen = i;
89 
90 	return (DW_DLE_NONE);
91 }
92 
93 int
94 _dwarf_loclist_find(Dwarf_Debug dbg, Dwarf_CU cu, uint64_t lloff,
95     Dwarf_Locdesc ***ret_llbuf, Dwarf_Signed *listlen,
96     Dwarf_Unsigned *entry_len, Dwarf_Error *error)
97 {
98 	Dwarf_Locdesc **llbuf;
99 	Dwarf_Section *ds;
100 	Dwarf_Signed ldlen;
101 	Dwarf_Unsigned off;
102 	int i, ret;
103 
104 	if ((ds = _dwarf_find_section(dbg, ".debug_loc")) == NULL) {
105 		DWARF_SET_ERROR(dbg, error, DW_DLE_NO_ENTRY);
106 		return (DW_DLE_NO_ENTRY);
107 	}
108 
109 	if (lloff >= ds->ds_size) {
110 		DWARF_SET_ERROR(dbg, error, DW_DLE_NO_ENTRY);
111 		return (DW_DLE_NO_ENTRY);
112 	}
113 
114 	/* Get the number of locdesc the first round. */
115 	off = lloff;
116 	ret = _dwarf_loclist_add_locdesc(dbg, cu, ds, &off, NULL, &ldlen,
117 	    NULL, error);
118 	if (ret != DW_DLE_NONE)
119 		return (ret);
120 
121 	if (ldlen == 0)
122 		return (DW_DLE_NO_ENTRY);
123 
124 	/*
125 	 * Dwarf_Locdesc list memory is allocated in this way (one more level
126 	 * of indirect) to make the loclist API be compatible with SGI libdwarf.
127 	 */
128 	if ((llbuf = calloc(ldlen, sizeof(Dwarf_Locdesc *))) == NULL) {
129 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
130 		return (DW_DLE_MEMORY);
131 	}
132 	for (i = 0; i < ldlen; i++) {
133 		if ((llbuf[i] = calloc(1, sizeof(Dwarf_Locdesc))) == NULL) {
134 			DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
135 			ret = DW_DLE_MEMORY;
136 			goto fail_cleanup;
137 		}
138 	}
139 
140 	off = lloff;
141 
142 	/* Fill in locdesc. */
143 	ret = _dwarf_loclist_add_locdesc(dbg, cu, ds, &off, llbuf, NULL,
144 	    entry_len, error);
145 	if (ret != DW_DLE_NONE)
146 		goto fail_cleanup;
147 
148 	*ret_llbuf = llbuf;
149 	*listlen = ldlen;
150 
151 	return (DW_DLE_NONE);
152 
153 fail_cleanup:
154 
155 	if (llbuf != NULL) {
156 		for (i = 0; i < ldlen; i++) {
157 			if (llbuf[i]->ld_s)
158 				free(llbuf[i]->ld_s);
159 			free(llbuf[i]);
160 		}
161 		free(llbuf);
162 	}
163 
164 	return (ret);
165 }
166