1 /* Read the dynamic section at DYN and fill in INFO with indices DT_*.
2 Copyright (C) 2012-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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 <https://www.gnu.org/licenses/>. */
19 /* Populate dynamic tags in l_info. */
21 #ifndef _GET_DYNAMIC_INFO_H
22 #define _GET_DYNAMIC_INFO_H
25 #include <dl-machine-rel.h>
26 #include <libc-diag.h>
28 static inline void __attribute__ ((unused
, always_inline
))
29 elf_get_dynamic_info (struct link_map
*l
, bool bootstrap
,
30 bool static_pie_bootstrap
)
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
;
38 #ifndef STATIC_PIE_BOOTSTRAP
39 if (!bootstrap
&& l
->l_ld
== NULL
)
43 ElfW(Dyn
) **info
= l
->l_info
;
45 for (ElfW(Dyn
) *dyn
= l
->l_ld
; dyn
->d_tag
!= DT_NULL
; dyn
++)
49 if ((d_tag_utype
) dyn
->d_tag
< DT_NUM
)
51 else if (dyn
->d_tag
>= DT_LOPROC
52 && dyn
->d_tag
< DT_LOPROC
+ DT_THISPROCNUM
)
53 i
= dyn
->d_tag
- DT_LOPROC
+ DT_NUM
;
54 else if ((d_tag_utype
) DT_VERSIONTAGIDX (dyn
->d_tag
) < DT_VERSIONTAGNUM
)
55 i
= VERSYMIDX (dyn
->d_tag
);
56 else if ((d_tag_utype
) DT_EXTRATAGIDX (dyn
->d_tag
) < DT_EXTRANUM
)
57 i
= DT_EXTRATAGIDX (dyn
->d_tag
) + DT_NUM
+ DT_THISPROCNUM
59 else if ((d_tag_utype
) DT_VALTAGIDX (dyn
->d_tag
) < DT_VALNUM
)
60 i
= DT_VALTAGIDX (dyn
->d_tag
) + DT_NUM
+ DT_THISPROCNUM
61 + DT_VERSIONTAGNUM
+ DT_EXTRANUM
;
62 else if ((d_tag_utype
) DT_ADDRTAGIDX (dyn
->d_tag
) < DT_ADDRNUM
)
63 i
= DT_ADDRTAGIDX (dyn
->d_tag
) + DT_NUM
+ DT_THISPROCNUM
64 + DT_VERSIONTAGNUM
+ DT_EXTRANUM
+ DT_VALNUM
;
71 /* Don't adjust .dynamic unnecessarily. */
72 if (l
->l_addr
!= 0 && dl_relocate_ld (l
))
74 ElfW(Addr
) l_addr
= l
->l_addr
;
76 # define ADJUST_DYN_INFO(tag) \
78 if (info[tag] != NULL) \
79 info[tag]->d_un.d_ptr += l_addr; \
82 ADJUST_DYN_INFO (DT_HASH
);
83 ADJUST_DYN_INFO (DT_PLTGOT
);
84 ADJUST_DYN_INFO (DT_STRTAB
);
85 ADJUST_DYN_INFO (DT_SYMTAB
);
86 # if ! ELF_MACHINE_NO_RELA
87 ADJUST_DYN_INFO (DT_RELA
);
89 # if ! ELF_MACHINE_NO_REL
90 ADJUST_DYN_INFO (DT_REL
);
92 ADJUST_DYN_INFO (DT_JMPREL
);
93 ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM
));
94 ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH
));
95 # undef ADJUST_DYN_INFO
97 if (info
[DT_PLTREL
] != NULL
)
99 #if ELF_MACHINE_NO_RELA
100 assert (info
[DT_PLTREL
]->d_un
.d_val
== DT_REL
);
101 #elif ELF_MACHINE_NO_REL
102 assert (info
[DT_PLTREL
]->d_un
.d_val
== DT_RELA
);
104 assert (info
[DT_PLTREL
]->d_un
.d_val
== DT_REL
105 || info
[DT_PLTREL
]->d_un
.d_val
== DT_RELA
);
108 #if ! ELF_MACHINE_NO_RELA
109 if (info
[DT_RELA
] != NULL
)
110 assert (info
[DT_RELAENT
]->d_un
.d_val
== sizeof (ElfW(Rela
)));
112 # if ! ELF_MACHINE_NO_REL
113 if (info
[DT_REL
] != NULL
)
114 assert (info
[DT_RELENT
]->d_un
.d_val
== sizeof (ElfW(Rel
)));
116 if (bootstrap
|| static_pie_bootstrap
)
118 assert (info
[DT_RUNPATH
] == NULL
);
119 assert (info
[DT_RPATH
] == NULL
);
123 /* Only the bind now flags are allowed. */
124 assert (info
[VERSYMIDX (DT_FLAGS_1
)] == NULL
125 || (info
[VERSYMIDX (DT_FLAGS_1
)]->d_un
.d_val
& ~DF_1_NOW
) == 0);
126 /* Flags must not be set for ld.so. */
127 assert (info
[DT_FLAGS
] == NULL
128 || (info
[DT_FLAGS
]->d_un
.d_val
& ~DF_BIND_NOW
) == 0);
132 if (info
[DT_FLAGS
] != NULL
)
134 /* Flags are used. Translate to the old form where available.
135 Since these l_info entries are only tested for NULL pointers it
136 is ok if they point to the DT_FLAGS entry. */
137 l
->l_flags
= info
[DT_FLAGS
]->d_un
.d_val
;
139 if (l
->l_flags
& DF_SYMBOLIC
)
140 info
[DT_SYMBOLIC
] = info
[DT_FLAGS
];
141 if (l
->l_flags
& DF_TEXTREL
)
142 info
[DT_TEXTREL
] = info
[DT_FLAGS
];
143 if (l
->l_flags
& DF_BIND_NOW
)
144 info
[DT_BIND_NOW
] = info
[DT_FLAGS
];
147 if (info
[VERSYMIDX (DT_FLAGS_1
)] != NULL
)
149 l
->l_flags_1
= info
[VERSYMIDX (DT_FLAGS_1
)]->d_un
.d_val
;
150 if (l
->l_flags_1
& DF_1_NODELETE
)
151 l
->l_nodelete_pending
= true;
153 /* Only DT_1_SUPPORTED_MASK bits are supported, and we would like
154 to assert this, but we can't. Users have been setting
155 unsupported DF_1_* flags for a long time and glibc has ignored
156 them. Therefore to avoid breaking existing applications the
157 best we can do is add a warning during debugging with the
158 intent of notifying the user of the problem. */
159 if (__builtin_expect (GLRO(dl_debug_mask
) & DL_DEBUG_FILES
, 0)
160 && l
->l_flags_1
& ~DT_1_SUPPORTED_MASK
)
161 _dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x "
163 l
->l_flags_1
& ~DT_1_SUPPORTED_MASK
);
165 if (l
->l_flags_1
& DF_1_NOW
)
166 info
[DT_BIND_NOW
] = info
[VERSYMIDX (DT_FLAGS_1
)];
169 if (info
[DT_RUNPATH
] != NULL
)
170 /* If both RUNPATH and RPATH are given, the latter is ignored. */
171 info
[DT_RPATH
] = NULL
;