1 /* Relocate a shared object and resolve its references to other loaded objects.
2 Copyright (C) 1995,96,97,98,99,2000 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 Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 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 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
25 #include <sys/types.h>
26 #include "dynamic-link.h"
30 _dl_relocate_object (struct link_map
*l
, struct r_scope_elem
*scope
[],
31 int lazy
, int consider_profiling
)
36 /* If DT_BIND_NOW is set relocate all references in this object. We
37 do not do this if we are profiling, of course. */
38 if (!consider_profiling
&& l
->l_info
[DT_BIND_NOW
])
41 if (__builtin_expect (_dl_debug_reloc
, 0))
42 _dl_debug_message (1, "\nrelocation processing: ",
43 l
->l_name
[0] ? l
->l_name
: _dl_argv
[0],
44 lazy
? " (lazy)\n" : "\n", NULL
);
46 if (__builtin_expect (l
->l_info
[DT_TEXTREL
] != NULL
, 0))
48 /* Bletch. We must make read-only segments writable
49 long enough to relocate them. */
51 for (ph
= l
->l_phdr
; ph
< &l
->l_phdr
[l
->l_phnum
]; ++ph
)
52 if (ph
->p_type
== PT_LOAD
&& (ph
->p_flags
& PF_W
) == 0)
54 caddr_t mapstart
= ((caddr_t
) l
->l_addr
+
55 (ph
->p_vaddr
& ~(_dl_pagesize
- 1)));
56 caddr_t mapend
= ((caddr_t
) l
->l_addr
+
57 ((ph
->p_vaddr
+ ph
->p_memsz
+ _dl_pagesize
- 1)
58 & ~(_dl_pagesize
- 1)));
59 if (__mprotect (mapstart
, mapend
- mapstart
,
60 PROT_READ
|PROT_WRITE
) < 0)
61 _dl_signal_error (errno
, l
->l_name
,
62 "cannot make segment writable for relocation");
67 /* Do the actual relocation of the object's GOT and other data. */
69 /* String table object symbols. */
70 const char *strtab
= (const void *) D_PTR (l
, l_info
[DT_STRTAB
]);
72 /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
73 #define RESOLVE_MAP(ref, version, flags) \
74 (ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
75 ? ((version) != NULL && (version)->hash != 0 \
76 ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, l, (ref), \
77 scope, (version), (flags)) \
78 : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), scope, \
81 #define RESOLVE(ref, version, flags) \
82 (ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
83 ? ((version) != NULL && (version)->hash != 0 \
84 ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, l, (ref), \
85 scope, (version), (flags)) \
86 : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), scope, \
90 #include "dynamic-link.h"
91 ELF_DYNAMIC_RELOCATE (l
, lazy
, consider_profiling
);
93 if (__builtin_expect (_dl_profile
!= NULL
, 0))
95 /* Allocate the array which will contain the already found
98 (ElfW(Addr
) *) calloc (sizeof (ElfW(Addr
)),
99 l
->l_info
[DT_PLTRELSZ
]->d_un
.d_val
);
100 if (l
->l_reloc_result
== NULL
)
101 _dl_sysdep_fatal (_dl_argv
[0] ?: "<program name unknown>",
102 "cannot allocate memory for profiling", NULL
);
106 /* Mark the object so we know this work has been done. */
109 /* DT_TEXTREL is now in level 2 and might phase out at some time.
110 But we rewrite the DT_FLAGS entry to make testing easier and
111 therefore it will be available at all time. */
112 if (__builtin_expect (l
->l_info
[DT_TEXTREL
] != NULL
, 0))
114 /* Undo the protection change we made before relocating. */
115 const ElfW(Phdr
) *ph
;
116 for (ph
= l
->l_phdr
; ph
< &l
->l_phdr
[l
->l_phnum
]; ++ph
)
117 if (ph
->p_type
== PT_LOAD
&& (ph
->p_flags
& PF_W
) == 0)
119 caddr_t mapstart
= ((caddr_t
) l
->l_addr
+
120 (ph
->p_vaddr
& ~(_dl_pagesize
- 1)));
121 caddr_t mapend
= ((caddr_t
) l
->l_addr
+
122 ((ph
->p_vaddr
+ ph
->p_memsz
+ _dl_pagesize
- 1)
123 & ~(_dl_pagesize
- 1)));
124 extern unsigned char _dl_pf_to_prot
[8];
127 if ((PF_R
| PF_W
| PF_X
) == 7
128 && (PROT_READ
| PROT_WRITE
| PROT_EXEC
) == 7)
129 prot
= _dl_pf_to_prot
[ph
->p_flags
& (PF_R
| PF_X
)];
133 if (ph
->p_flags
& PF_R
)
135 if (ph
->p_flags
& PF_X
)
139 if (__mprotect (mapstart
, mapend
- mapstart
, prot
) < 0)
140 _dl_signal_error (errno
, l
->l_name
,
141 "can't restore segment prot after reloc");
144 CLEAR_CACHE (mapstart
, mapend
);
150 #include "../stdio-common/_itoa.h"
151 #define DIGIT(b) _itoa_lower_digits[(b) & 0xf];
155 _dl_reloc_bad_type (struct link_map
*map
, uint_fast8_t type
, int plt
)
157 extern const char _itoa_lower_digits
[];
160 char msg
[] = "unexpected PLT reloc type 0x??";
161 msg
[sizeof msg
- 3] = DIGIT(type
>> 4);
162 msg
[sizeof msg
- 2] = DIGIT(type
);
163 _dl_signal_error (0, map
->l_name
, msg
);
167 char msg
[] = "unexpected reloc type 0x??";
168 msg
[sizeof msg
- 3] = DIGIT(type
>> 4);
169 msg
[sizeof msg
- 2] = DIGIT(type
);
170 _dl_signal_error (0, map
->l_name
, msg
);