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sourceware.org Git - glibc.git/blob - elf/dl-reloc.c
1 /* Relocate a shared object and resolve its references to other loaded objects.
2 Copyright (C) 1995, 1996, 1997, 1998 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 link_map
*scope
[], int lazy
)
36 _dl_debug_message (1, "\nrelocation processing: ",
37 l
->l_name
[0] ? l
->l_name
: _dl_argv
[0], "\n", NULL
);
39 if (l
->l_info
[DT_TEXTREL
])
41 /* Bletch. We must make read-only segments writable
42 long enough to relocate them. */
44 for (ph
= l
->l_phdr
; ph
< &l
->l_phdr
[l
->l_phnum
]; ++ph
)
45 if (ph
->p_type
== PT_LOAD
&& (ph
->p_flags
& PF_W
) == 0)
47 caddr_t mapstart
= ((caddr_t
) l
->l_addr
+
48 (ph
->p_vaddr
& ~(_dl_pagesize
- 1)));
49 caddr_t mapend
= ((caddr_t
) l
->l_addr
+
50 ((ph
->p_vaddr
+ ph
->p_memsz
+ _dl_pagesize
- 1)
51 & ~(_dl_pagesize
- 1)));
52 if (__mprotect (mapstart
, mapend
- mapstart
,
53 PROT_READ
|PROT_WRITE
) < 0)
54 _dl_signal_error (errno
, l
->l_name
,
55 "cannot make segment writable for relocation");
60 /* Do the actual relocation of the object's GOT and other data. */
62 const char *strtab
/* String table object symbols. */
63 = ((void *) l
->l_addr
+ l
->l_info
[DT_STRTAB
]->d_un
.d_ptr
);
65 /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
66 #define RESOLVE(ref, version, flags) \
67 ((version) != NULL && (version)->hash != 0 \
68 ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, (ref), scope, \
69 l->l_name, (version), (flags)) \
70 : _dl_lookup_symbol (strtab + (*ref)->st_name, (ref), scope, \
73 #include "dynamic-link.h"
74 ELF_DYNAMIC_RELOCATE (l
, lazy
, 1);
76 if (_dl_profile_map
== l
)
78 /* Allocate the array which will contain the already found
81 (ElfW(Addr
) *) calloc (sizeof (ElfW(Addr
)),
82 l
->l_info
[DT_PLTRELSZ
]->d_un
.d_val
);
83 if (l
->l_reloc_result
== NULL
)
84 _dl_sysdep_fatal (_dl_argv
[0] ?: "<program name unknown>",
85 "cannot allocate memory for profiling", NULL
);
89 /* Mark the object so we know this work has been done. */
92 if (l
->l_info
[DT_TEXTREL
])
94 /* Undo the protection change we made before relocating. */
96 for (ph
= l
->l_phdr
; ph
< &l
->l_phdr
[l
->l_phnum
]; ++ph
)
97 if (ph
->p_type
== PT_LOAD
&& (ph
->p_flags
& PF_W
) == 0)
99 caddr_t mapstart
= ((caddr_t
) l
->l_addr
+
100 (ph
->p_vaddr
& ~(_dl_pagesize
- 1)));
101 caddr_t mapend
= ((caddr_t
) l
->l_addr
+
102 ((ph
->p_vaddr
+ ph
->p_memsz
+ _dl_pagesize
- 1)
103 & ~(_dl_pagesize
- 1)));
105 if (ph
->p_flags
& PF_R
)
107 if (ph
->p_flags
& PF_X
)
109 if (__mprotect (mapstart
, mapend
- mapstart
, prot
) < 0)
110 _dl_signal_error (errno
, l
->l_name
,
111 "can't restore segment prot after reloc");
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