1/* Read the dynamic section at DYN and fill in INFO with indices DT_*.
2 Copyright (C) 2012-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <assert.h>
20#include <libc-internal.h>
21
22#ifndef RESOLVE_MAP
23static
24#else
25auto
26#endif
27inline void __attribute__ ((unused, always_inline))
28elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp)
29{
30 ElfW(Dyn) *dyn = l->l_ld;
31 ElfW(Dyn) **info;
32#if __ELF_NATIVE_CLASS == 32
33 typedef Elf32_Word d_tag_utype;
34#elif __ELF_NATIVE_CLASS == 64
35 typedef Elf64_Xword d_tag_utype;
36#endif
37
38#ifndef RTLD_BOOTSTRAP
39 if (dyn == NULL)
40 return;
41#endif
42
43 info = l->l_info;
44
45 while (dyn->d_tag != DT_NULL)
46 {
47 if ((d_tag_utype) dyn->d_tag < DT_NUM)
48 info[dyn->d_tag] = dyn;
49 else if (dyn->d_tag >= DT_LOPROC &&
50 dyn->d_tag < DT_LOPROC + DT_THISPROCNUM)
51 {
52 /* This does not violate the array bounds of l->l_info, but
53 gcc 4.6 on sparc somehow does not see this. */
54 DIAG_PUSH_NEEDS_COMMENT;
55 DIAG_IGNORE_NEEDS_COMMENT (4.6,
56 "-Warray-bounds");
57 info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
58 DIAG_POP_NEEDS_COMMENT;
59 }
60 else if ((d_tag_utype) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
61 info[VERSYMIDX (dyn->d_tag)] = dyn;
62 else if ((d_tag_utype) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
63 info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
64 + DT_VERSIONTAGNUM] = dyn;
65 else if ((d_tag_utype) DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM)
66 info[DT_VALTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
67 + DT_VERSIONTAGNUM + DT_EXTRANUM] = dyn;
68 else if ((d_tag_utype) DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM)
69 info[DT_ADDRTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
70 + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] = dyn;
71 ++dyn;
72 }
73
74#define DL_RO_DYN_TEMP_CNT 8
75
76#ifndef DL_RO_DYN_SECTION
77 /* Don't adjust .dynamic unnecessarily. */
78 if (l->l_addr != 0)
79 {
80 ElfW(Addr) l_addr = l->l_addr;
81 int cnt = 0;
82
83# define ADJUST_DYN_INFO(tag) \
84 do \
85 if (info[tag] != NULL) \
86 { \
87 if (temp) \
88 { \
89 temp[cnt].d_tag = info[tag]->d_tag; \
90 temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr; \
91 info[tag] = temp + cnt++; \
92 } \
93 else \
94 info[tag]->d_un.d_ptr += l_addr; \
95 } \
96 while (0)
97
98 ADJUST_DYN_INFO (DT_HASH);
99 ADJUST_DYN_INFO (DT_PLTGOT);
100 ADJUST_DYN_INFO (DT_STRTAB);
101 ADJUST_DYN_INFO (DT_SYMTAB);
102# if ! ELF_MACHINE_NO_RELA
103 ADJUST_DYN_INFO (DT_RELA);
104# endif
105# if ! ELF_MACHINE_NO_REL
106 ADJUST_DYN_INFO (DT_REL);
107# endif
108 ADJUST_DYN_INFO (DT_JMPREL);
109 ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
110 ADJUST_DYN_INFO (DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM
111 + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM);
112# undef ADJUST_DYN_INFO
113 assert (cnt <= DL_RO_DYN_TEMP_CNT);
114 }
115#endif
116 if (info[DT_PLTREL] != NULL)
117 {
118#if ELF_MACHINE_NO_RELA
119 assert (info[DT_PLTREL]->d_un.d_val == DT_REL);
120#elif ELF_MACHINE_NO_REL
121 assert (info[DT_PLTREL]->d_un.d_val == DT_RELA);
122#else
123 assert (info[DT_PLTREL]->d_un.d_val == DT_REL
124 || info[DT_PLTREL]->d_un.d_val == DT_RELA);
125#endif
126 }
127#if ! ELF_MACHINE_NO_RELA
128 if (info[DT_RELA] != NULL)
129 assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
130# endif
131# if ! ELF_MACHINE_NO_REL
132 if (info[DT_REL] != NULL)
133 assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
134#endif
135#ifdef RTLD_BOOTSTRAP
136 /* Only the bind now flags are allowed. */
137 assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
138 || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);
139 assert (info[DT_FLAGS] == NULL
140 || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);
141 /* Flags must not be set for ld.so. */
142 assert (info[DT_RUNPATH] == NULL);
143 assert (info[DT_RPATH] == NULL);
144#else
145 if (info[DT_FLAGS] != NULL)
146 {
147 /* Flags are used. Translate to the old form where available.
148 Since these l_info entries are only tested for NULL pointers it
149 is ok if they point to the DT_FLAGS entry. */
150 l->l_flags = info[DT_FLAGS]->d_un.d_val;
151
152 if (l->l_flags & DF_SYMBOLIC)
153 info[DT_SYMBOLIC] = info[DT_FLAGS];
154 if (l->l_flags & DF_TEXTREL)
155 info[DT_TEXTREL] = info[DT_FLAGS];
156 if (l->l_flags & DF_BIND_NOW)
157 info[DT_BIND_NOW] = info[DT_FLAGS];
158 }
159 if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
160 {
161 l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
162
163 /* Only DT_1_SUPPORTED_MASK bits are supported, and we would like
164 to assert this, but we can't. Users have been setting
165 unsupported DF_1_* flags for a long time and glibc has ignored
166 them. Therefore to avoid breaking existing applications the
167 best we can do is add a warning during debugging with the
168 intent of notifying the user of the problem. */
169 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
170 && l->l_flags_1 & ~DT_1_SUPPORTED_MASK)
171 _dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x in DT_FLAGS_1.\n",
172 l->l_flags_1 & ~DT_1_SUPPORTED_MASK);
173
174 if (l->l_flags_1 & DF_1_NOW)
175 info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)];
176 }
177 if (info[DT_RUNPATH] != NULL)
178 /* If both RUNPATH and RPATH are given, the latter is ignored. */
179 info[DT_RPATH] = NULL;
180#endif
181}
182