Line data Source code
1 : /* Enumerate the PC ranges covered by a DIE.
2 : Copyright (C) 2005, 2007, 2009 Red Hat, Inc.
3 : This file is part of elfutils.
4 :
5 : This file is free software; you can redistribute it and/or modify
6 : it under the terms of either
7 :
8 : * the GNU Lesser General Public License as published by the Free
9 : Software Foundation; either version 3 of the License, or (at
10 : your option) any later version
11 :
12 : or
13 :
14 : * the GNU General Public License as published by the Free
15 : Software Foundation; either version 2 of the License, or (at
16 : your option) any later version
17 :
18 : or both in parallel, as here.
19 :
20 : elfutils is distributed in the hope that it will be useful, but
21 : WITHOUT ANY WARRANTY; without even the implied warranty of
22 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 : General Public License for more details.
24 :
25 : You should have received copies of the GNU General Public License and
26 : the GNU Lesser General Public License along with this program. If
27 : not, see <http://www.gnu.org/licenses/>. */
28 :
29 : #ifdef HAVE_CONFIG_H
30 : # include <config.h>
31 : #endif
32 :
33 : #include "libdwP.h"
34 : #include <dwarf.h>
35 : #include <assert.h>
36 :
37 : /* Read up begin/end pair and increment read pointer.
38 : - If it's normal range record, set up `*beginp' and `*endp' and return 0.
39 : - If it's base address selection record, set up `*basep' and return 1.
40 : - If it's end of rangelist, don't set anything and return 2
41 : - If an error occurs, don't set anything and return -1. */
42 : internal_function int
43 123 : __libdw_read_begin_end_pair_inc (Dwarf *dbg, int sec_index,
44 : unsigned char **addrp, int width,
45 : Dwarf_Addr *beginp, Dwarf_Addr *endp,
46 : Dwarf_Addr *basep)
47 : {
48 123 : Dwarf_Addr escape = (width == 8 ? (Elf64_Addr) -1
49 123 : : (Elf64_Addr) (Elf32_Addr) -1);
50 : Dwarf_Addr begin;
51 : Dwarf_Addr end;
52 :
53 123 : unsigned char *addr = *addrp;
54 123 : bool begin_relocated = READ_AND_RELOCATE (__libdw_relocate_address, begin);
55 123 : bool end_relocated = READ_AND_RELOCATE (__libdw_relocate_address, end);
56 123 : *addrp = addr;
57 :
58 : /* Unrelocated escape for begin means base address selection. */
59 123 : if (begin == escape && !begin_relocated)
60 : {
61 1 : if (unlikely (end == escape))
62 : {
63 0 : __libdw_seterrno (DWARF_E_INVALID_DWARF);
64 0 : return -1;
65 : }
66 :
67 1 : if (basep != NULL)
68 1 : *basep = end;
69 : return 1;
70 : }
71 :
72 : /* Unrelocated pair of zeroes means end of range list. */
73 122 : if (begin == 0 && end == 0 && !begin_relocated && !end_relocated)
74 : return 2;
75 :
76 : /* Don't check for begin_relocated == end_relocated. Serve the data
77 : to the client even though it may be buggy. */
78 114 : *beginp = begin;
79 114 : *endp = end;
80 :
81 114 : return 0;
82 : }
83 :
84 : ptrdiff_t
85 1877 : dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
86 : Dwarf_Addr *startp, Dwarf_Addr *endp)
87 : {
88 1877 : if (die == NULL)
89 : return -1;
90 :
91 1877 : if (offset == 0
92 : /* Usually there is a single contiguous range. */
93 1431 : && INTUSE(dwarf_highpc) (die, endp) == 0
94 786 : && INTUSE(dwarf_lowpc) (die, startp) == 0)
95 : /* A offset into .debug_ranges will never be 1, it must be at least a
96 : multiple of 4. So we can return 1 as a special case value to mark
97 : there are no ranges to look for on the next call. */
98 : return 1;
99 :
100 1091 : if (offset == 1)
101 : return 0;
102 :
103 : /* We have to look for a noncontiguous range. */
104 :
105 653 : const Elf_Data *d = die->cu->dbg->sectiondata[IDX_debug_ranges];
106 653 : if (d == NULL && offset != 0)
107 : {
108 0 : __libdw_seterrno (DWARF_E_NO_DEBUG_RANGES);
109 0 : return -1;
110 : }
111 :
112 : unsigned char *readp;
113 : unsigned char *readendp;
114 653 : if (offset == 0)
115 : {
116 : Dwarf_Attribute attr_mem;
117 645 : Dwarf_Attribute *attr = INTUSE(dwarf_attr) (die, DW_AT_ranges,
118 : &attr_mem);
119 645 : if (attr == NULL)
120 : /* No PC attributes in this DIE at all, so an empty range list. */
121 638 : return 0;
122 :
123 : Dwarf_Word start_offset;
124 7 : if ((readp = __libdw_formptr (attr, IDX_debug_ranges,
125 : DWARF_E_NO_DEBUG_RANGES,
126 : &readendp, &start_offset)) == NULL)
127 : return -1;
128 :
129 7 : offset = start_offset;
130 : assert ((Dwarf_Word) offset == start_offset);
131 :
132 : /* Fetch the CU's base address. */
133 14 : Dwarf_Die cudie = CUDIE (attr->cu);
134 :
135 : /* Find the base address of the compilation unit. It will
136 : normally be specified by DW_AT_low_pc. In DWARF-3 draft 4,
137 : the base address could be overridden by DW_AT_entry_pc. It's
138 : been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc
139 : for compilation units with discontinuous ranges. */
140 7 : if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0)
141 1 : && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie,
142 : DW_AT_entry_pc,
143 : &attr_mem),
144 : basep) != 0)
145 1 : *basep = (Dwarf_Addr) -1;
146 : }
147 : else
148 : {
149 8 : if (__libdw_offset_in_section (die->cu->dbg,
150 : IDX_debug_ranges, offset, 1))
151 : return -1l;
152 :
153 8 : readp = d->d_buf + offset;
154 8 : readendp = d->d_buf + d->d_size;
155 : }
156 :
157 : next:
158 16 : if (readendp - readp < die->cu->address_size * 2)
159 : goto invalid;
160 :
161 : Dwarf_Addr begin;
162 : Dwarf_Addr end;
163 :
164 16 : switch (__libdw_read_begin_end_pair_inc (die->cu->dbg, IDX_debug_ranges,
165 : &readp, die->cu->address_size,
166 : &begin, &end, basep))
167 : {
168 : case 0:
169 : break;
170 : case 1:
171 : goto next;
172 : case 2:
173 : return 0;
174 : default:
175 0 : return -1l;
176 : }
177 :
178 : /* We have an address range entry. Check that we have a base. */
179 14 : if (*basep == (Dwarf_Addr) -1)
180 : {
181 0 : if (INTUSE(dwarf_errno) () == 0)
182 : {
183 : invalid:
184 0 : __libdw_seterrno (DWARF_E_INVALID_DWARF);
185 : }
186 : return -1;
187 : }
188 :
189 14 : *startp = *basep + begin;
190 14 : *endp = *basep + end;
191 14 : return readp - (unsigned char *) d->d_buf;
192 : }
193 : INTDEF (dwarf_ranges)
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