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d66e34cd | 1 | /* Relocate a shared object and resolve its references to other loaded objects. |
ea7eb7e3 | 2 | Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. |
afd4eb37 | 3 | This file is part of the GNU C Library. |
d66e34cd | 4 | |
afd4eb37 UD |
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. | |
d66e34cd | 9 | |
afd4eb37 UD |
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. | |
d66e34cd | 14 | |
afd4eb37 UD |
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. */ | |
d66e34cd | 19 | |
ea7eb7e3 | 20 | #include <errno.h> |
d66e34cd | 21 | #include <link.h> |
ea7eb7e3 | 22 | #include <stdlib.h> |
d66e34cd | 23 | #include <unistd.h> |
ea7eb7e3 UD |
24 | #include <sys/mman.h> |
25 | #include <sys/types.h> | |
d66e34cd RM |
26 | #include "dynamic-link.h" |
27 | ||
3996f34b | 28 | |
d66e34cd | 29 | void |
ba79d61b | 30 | _dl_relocate_object (struct link_map *l, struct link_map *scope[], int lazy) |
d66e34cd | 31 | { |
d66e34cd RM |
32 | if (l->l_relocated) |
33 | return; | |
34 | ||
8193034b UD |
35 | if (_dl_debug_reloc) |
36 | _dl_debug_message (1, "\nrelocation processing: ", | |
37 | l->l_name[0] ? l->l_name : _dl_argv[0], "\n", NULL); | |
38 | ||
d66e34cd RM |
39 | if (l->l_info[DT_TEXTREL]) |
40 | { | |
41 | /* Bletch. We must make read-only segments writable | |
42 | long enough to relocate them. */ | |
266180eb | 43 | const ElfW(Phdr) *ph; |
d66e34cd RM |
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) | |
46 | { | |
47 | caddr_t mapstart = ((caddr_t) l->l_addr + | |
266180eb | 48 | (ph->p_vaddr & ~(_dl_pagesize - 1))); |
d66e34cd | 49 | caddr_t mapend = ((caddr_t) l->l_addr + |
266180eb RM |
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) | |
421f82e5 | 54 | _dl_signal_error (errno, l->l_name, |
d66e34cd RM |
55 | "cannot make segment writable for relocation"); |
56 | } | |
57 | } | |
58 | ||
59 | { | |
ba79d61b | 60 | /* Do the actual relocation of the object's GOT and other data. */ |
d66e34cd | 61 | |
ba79d61b | 62 | const char *strtab /* String table object symbols. */ |
d66e34cd | 63 | = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); |
d66e34cd | 64 | |
f51d1dfd | 65 | /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */ |
c84142e8 | 66 | #define RESOLVE(ref, version, flags) \ |
bc9f6000 | 67 | ((version) != NULL && (version)->hash != 0 \ |
c84142e8 UD |
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, \ | |
71 | l->l_name, (flags))) | |
f51d1dfd RM |
72 | |
73 | #include "dynamic-link.h" | |
3996f34b | 74 | ELF_DYNAMIC_RELOCATE (l, lazy, 1); |
ea7eb7e3 UD |
75 | |
76 | if (_dl_profile_map == l) | |
77 | { | |
78 | /* Allocate the array which will contain the already found | |
79 | relocations. */ | |
80 | l->l_reloc_result = | |
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); | |
86 | } | |
d66e34cd RM |
87 | } |
88 | ||
714a562f | 89 | /* Mark the object so we know this work has been done. */ |
d66e34cd RM |
90 | l->l_relocated = 1; |
91 | ||
92 | if (l->l_info[DT_TEXTREL]) | |
93 | { | |
94 | /* Undo the protection change we made before relocating. */ | |
266180eb | 95 | const ElfW(Phdr) *ph; |
d66e34cd RM |
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) | |
98 | { | |
99 | caddr_t mapstart = ((caddr_t) l->l_addr + | |
266180eb | 100 | (ph->p_vaddr & ~(_dl_pagesize - 1))); |
d66e34cd | 101 | caddr_t mapend = ((caddr_t) l->l_addr + |
266180eb RM |
102 | ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1) |
103 | & ~(_dl_pagesize - 1))); | |
d66e34cd RM |
104 | int prot = 0; |
105 | if (ph->p_flags & PF_R) | |
106 | prot |= PROT_READ; | |
107 | if (ph->p_flags & PF_X) | |
108 | prot |= PROT_EXEC; | |
266180eb | 109 | if (__mprotect (mapstart, mapend - mapstart, prot) < 0) |
421f82e5 | 110 | _dl_signal_error (errno, l->l_name, |
d66e34cd RM |
111 | "can't restore segment prot after reloc"); |
112 | } | |
113 | } | |
d66e34cd | 114 | } |