1 /* Common code for ebl reloc functions.
2 Copyright (C) 2005, 2006 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 #include "libebl_CPU.h"
30 #include <assert.h>
31
32 #define R_TYPE(name) PASTE (RELOC_PREFIX, name)
33 #define PASTE(a, b) PASTE_1 (a, b)
34 #define PASTE_1(a, b) a##b
35 #define R_NAME(name) R_NAME_1 (RELOC_PREFIX, name)
36 #define R_NAME_1(prefix, type) R_NAME_2 (prefix, type)
37 #define R_NAME_2(prefix, type) #prefix #type
38
39 #define RELOC_TYPES STRINGIFIED_PASTE (BACKEND, reloc.def)
40 #define STRINGIFIED_PASTE(a, b) STRINGIFY (PASTE (a, b))
41 #define STRINGIFY(x) STRINGIFY_1 (x)
42 #define STRINGIFY_1(x) #x
43
44 /* Provide a table of reloc type names, in a PIC-friendly fashion. */
45
EBLHOOK(reloc_nametable)46 static const struct EBLHOOK(reloc_nametable)
47 {
48 char zero;
49 #define RELOC_TYPE(type, uses) \
50 char name_##type[sizeof R_NAME (type)];
51 #include RELOC_TYPES
52 #undef RELOC_TYPE
53 } EBLHOOK(reloc_nametable) =
54 {
55 '\0',
56 #define RELOC_TYPE(type, uses) R_NAME (type),
57 #include RELOC_TYPES
58 #undef RELOC_TYPE
59 };
60 #define reloc_namestr (&EBLHOOK(reloc_nametable).zero)
61
62 static const uint_fast16_t EBLHOOK(reloc_nameidx)[] =
63 {
64 #define RELOC_TYPE(type, uses) \
65 [R_TYPE (type)] = offsetof (struct EBLHOOK(reloc_nametable), name_##type),
66 #include RELOC_TYPES
67 #undef RELOC_TYPE
68 };
69 #define nreloc \
70 ((int) (sizeof EBLHOOK(reloc_nameidx) / sizeof EBLHOOK(reloc_nameidx)[0]))
71
72 #define REL (1 << (ET_REL - 1))
73 #define EXEC (1 << (ET_EXEC - 1))
74 #define DYN (1 << (ET_DYN - 1))
75 static const uint8_t EBLHOOK(reloc_valid)[] =
76 {
77 #define RELOC_TYPE(type, uses) [R_TYPE (type)] = uses,
78 #include RELOC_TYPES
79 #undef RELOC_TYPE
80 };
81 #undef REL
82 #undef EXEC
83 #undef DYN
84
85 const char *
EBLHOOK(reloc_type_name)86 EBLHOOK(reloc_type_name) (int reloc,
87 char *buf __attribute__ ((unused)),
88 size_t len __attribute__ ((unused)))
89 {
90 #ifdef RELOC_TYPE_ID
91 reloc = RELOC_TYPE_ID (reloc);
92 #endif
93
94 if (reloc >= 0 && reloc < nreloc && EBLHOOK(reloc_nameidx)[reloc] != 0)
95 return &reloc_namestr[EBLHOOK(reloc_nameidx)[reloc]];
96 return NULL;
97 }
98
99 bool
EBLHOOK(reloc_type_check)100 EBLHOOK(reloc_type_check) (int reloc)
101 {
102 #ifdef RELOC_TYPE_ID
103 reloc = RELOC_TYPE_ID (reloc);
104 #endif
105
106 return reloc >= 0 && reloc < nreloc && EBLHOOK(reloc_nameidx)[reloc] != 0;
107 }
108
109 bool
EBLHOOK(reloc_valid_use)110 EBLHOOK(reloc_valid_use) (Elf *elf, int reloc)
111 {
112 uint8_t uses;
113
114 GElf_Ehdr ehdr_mem;
115 GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
116 assert (ehdr != NULL);
117 uint8_t type = ehdr->e_type;
118
119 #ifdef RELOC_TYPE_ID
120 reloc = RELOC_TYPE_ID (reloc);
121 #endif
122
123 uses = EBLHOOK(reloc_valid)[reloc];
124 return type > ET_NONE && type < ET_CORE && (uses & (1 << (type - 1)));
125 }
126
127
128 bool
EBLHOOK(copy_reloc_p)129 EBLHOOK(copy_reloc_p) (int reloc)
130 {
131 return reloc == R_TYPE (COPY);
132 }
133
134 bool
EBLHOOK(none_reloc_p)135 EBLHOOK(none_reloc_p) (int reloc)
136 {
137 return reloc == R_TYPE (NONE);
138 }
139
140 #ifndef NO_RELATIVE_RELOC
141 bool
EBLHOOK(relative_reloc_p)142 EBLHOOK(relative_reloc_p) (int reloc)
143 {
144 return reloc == R_TYPE (RELATIVE);
145 }
146 #endif
147
148 static void
EBLHOOK(init_reloc)149 EBLHOOK(init_reloc) (Ebl *ebl)
150 {
151 ebl->reloc_type_name = EBLHOOK(reloc_type_name);
152 ebl->reloc_type_check = EBLHOOK(reloc_type_check);
153 ebl->reloc_valid_use = EBLHOOK(reloc_valid_use);
154 ebl->copy_reloc_p = EBLHOOK(copy_reloc_p);
155 ebl->none_reloc_p = EBLHOOK(none_reloc_p);
156 #ifndef NO_RELATIVE_RELOC
157 ebl->relative_reloc_p = EBLHOOK(relative_reloc_p);
158 #endif
159 }
160