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d66e34cd | 1 | /* Relocate a shared object and resolve its references to other loaded objects. |
a42195db | 2 | Copyright (C) 1995,96,97,98,99,2000 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> |
ea7eb7e3 | 21 | #include <stdlib.h> |
d66e34cd | 22 | #include <unistd.h> |
a42195db | 23 | #include <ldsodefs.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 |
be935610 UD |
30 | _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[], |
31 | int lazy, int consider_profiling) | |
d66e34cd | 32 | { |
d66e34cd RM |
33 | if (l->l_relocated) |
34 | return; | |
35 | ||
88187dcc UD |
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]) | |
39 | lazy = 0; | |
40 | ||
466a0ec9 | 41 | if (__builtin_expect (_dl_debug_reloc, 0)) |
8193034b | 42 | _dl_debug_message (1, "\nrelocation processing: ", |
88187dcc UD |
43 | l->l_name[0] ? l->l_name : _dl_argv[0], |
44 | lazy ? " (lazy)\n" : "\n", NULL); | |
8193034b | 45 | |
dc051821 | 46 | if (__builtin_expect (l->l_info[DT_TEXTREL] != NULL, 0)) |
d66e34cd RM |
47 | { |
48 | /* Bletch. We must make read-only segments writable | |
49 | long enough to relocate them. */ | |
266180eb | 50 | const ElfW(Phdr) *ph; |
d66e34cd RM |
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) | |
53 | { | |
54 | caddr_t mapstart = ((caddr_t) l->l_addr + | |
266180eb | 55 | (ph->p_vaddr & ~(_dl_pagesize - 1))); |
d66e34cd | 56 | caddr_t mapend = ((caddr_t) l->l_addr + |
266180eb RM |
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) | |
421f82e5 | 61 | _dl_signal_error (errno, l->l_name, |
d66e34cd RM |
62 | "cannot make segment writable for relocation"); |
63 | } | |
64 | } | |
65 | ||
66 | { | |
ba79d61b | 67 | /* Do the actual relocation of the object's GOT and other data. */ |
d66e34cd | 68 | |
f420344c | 69 | /* String table object symbols. */ |
a42195db | 70 | const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]); |
d66e34cd | 71 | |
f51d1dfd | 72 | /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */ |
c0282c06 UD |
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, \ | |
79 | (flags))) \ | |
80 | : l) | |
c84142e8 | 81 | #define RESOLVE(ref, version, flags) \ |
6aa29abe | 82 | (ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \ |
06535ae9 UD |
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, \ | |
87 | (flags))) \ | |
88 | : l->l_addr) | |
f51d1dfd RM |
89 | |
90 | #include "dynamic-link.h" | |
c0fb8a56 | 91 | ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling); |
ea7eb7e3 | 92 | |
655ab929 | 93 | if (__builtin_expect (_dl_profile != NULL, 0)) |
ea7eb7e3 UD |
94 | { |
95 | /* Allocate the array which will contain the already found | |
96 | relocations. */ | |
97 | l->l_reloc_result = | |
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); | |
103 | } | |
d66e34cd RM |
104 | } |
105 | ||
714a562f | 106 | /* Mark the object so we know this work has been done. */ |
d66e34cd RM |
107 | l->l_relocated = 1; |
108 | ||
06535ae9 UD |
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. */ | |
dc051821 | 112 | if (__builtin_expect (l->l_info[DT_TEXTREL] != NULL, 0)) |
d66e34cd RM |
113 | { |
114 | /* Undo the protection change we made before relocating. */ | |
266180eb | 115 | const ElfW(Phdr) *ph; |
d66e34cd RM |
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) | |
118 | { | |
119 | caddr_t mapstart = ((caddr_t) l->l_addr + | |
266180eb | 120 | (ph->p_vaddr & ~(_dl_pagesize - 1))); |
d66e34cd | 121 | caddr_t mapend = ((caddr_t) l->l_addr + |
266180eb RM |
122 | ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1) |
123 | & ~(_dl_pagesize - 1))); | |
24d60840 UD |
124 | extern unsigned char _dl_pf_to_prot[8]; |
125 | int prot; | |
126 | ||
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)]; | |
130 | else | |
131 | { | |
132 | prot = 0; | |
133 | if (ph->p_flags & PF_R) | |
134 | prot |= PROT_READ; | |
135 | if (ph->p_flags & PF_X) | |
136 | prot |= PROT_EXEC; | |
137 | } | |
138 | ||
266180eb | 139 | if (__mprotect (mapstart, mapend - mapstart, prot) < 0) |
421f82e5 | 140 | _dl_signal_error (errno, l->l_name, |
d66e34cd | 141 | "can't restore segment prot after reloc"); |
63a34b0f UD |
142 | |
143 | #ifdef CLEAR_CACHE | |
144 | CLEAR_CACHE (mapstart, mapend); | |
736d0841 | 145 | #endif |
d66e34cd RM |
146 | } |
147 | } | |
d66e34cd | 148 | } |
421c80d2 RM |
149 | |
150 | #include "../stdio-common/_itoa.h" | |
151 | #define DIGIT(b) _itoa_lower_digits[(b) & 0xf]; | |
152 | ||
153 | void | |
154 | internal_function | |
155 | _dl_reloc_bad_type (struct link_map *map, uint_fast8_t type, int plt) | |
156 | { | |
157 | extern const char _itoa_lower_digits[]; | |
158 | if (plt) | |
159 | { | |
b227a3a6 | 160 | char msg[] = "unexpected PLT reloc type 0x??"; |
5d693ae3 | 161 | msg[sizeof msg - 3] = DIGIT(type >> 4); |
676d12fd | 162 | msg[sizeof msg - 2] = DIGIT(type); |
421c80d2 RM |
163 | _dl_signal_error (0, map->l_name, msg); |
164 | } | |
165 | else | |
166 | { | |
b227a3a6 | 167 | char msg[] = "unexpected reloc type 0x??"; |
5d693ae3 | 168 | msg[sizeof msg - 3] = DIGIT(type >> 4); |
676d12fd | 169 | msg[sizeof msg - 2] = DIGIT(type); |
421c80d2 RM |
170 | _dl_signal_error (0, map->l_name, msg); |
171 | } | |
172 | } |