mdreloc.c revision 1.16 1 /* $NetBSD: mdreloc.c,v 1.16 2003/07/02 15:29:34 marcus Exp $ */
2
3 #include <sys/types.h>
4 #include <sys/stat.h>
5
6 #include "debug.h"
7 #include "rtld.h"
8
9 void _rtld_bind_start(void);
10
11 void
12 _rtld_setup_pltgot(const Obj_Entry *obj)
13 {
14 obj->pltgot[1] = (Elf_Addr) obj;
15 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
16 }
17
18 void
19 _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
20 {
21 const Elf_Rela *rela = 0, *relalim;
22 Elf_Addr relasz = 0;
23 Elf_Addr *where;
24
25 for (; dynp->d_tag != DT_NULL; dynp++) {
26 switch (dynp->d_tag) {
27 case DT_RELA:
28 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
29 break;
30 case DT_RELASZ:
31 relasz = dynp->d_un.d_val;
32 break;
33 }
34 }
35 relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
36 for (; rela < relalim; rela++) {
37 where = (Elf_Addr *)(relocbase + rela->r_offset);
38 *where = (Elf_Addr)(relocbase + rela->r_addend);
39 }
40 }
41
42 int
43 _rtld_relocate_nonplt_objects(obj)
44 const Obj_Entry *obj;
45 {
46 const Elf_Rela *rela;
47
48 for (rela = obj->rela; rela < obj->relalim; rela++) {
49 Elf_Addr *where;
50 const Elf_Sym *def;
51 const Obj_Entry *defobj;
52 Elf_Addr tmp;
53 unsigned long symnum;
54
55 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
56 symnum = ELF_R_SYM(rela->r_info);
57
58 switch (ELF_R_TYPE(rela->r_info)) {
59 case R_TYPE(NONE):
60 break;
61
62 #if 1 /* XXX should not occur */
63 case R_TYPE(GOT32):
64 def = _rtld_find_symdef(symnum, obj, &defobj, false);
65 if (def == NULL)
66 return -1;
67
68 tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
69 rela->r_addend);
70 if (*where != tmp)
71 *where = tmp;
72 rdbg(("GOT32 %s in %s --> %p in %s",
73 obj->strtab + obj->symtab[symnum].st_name,
74 obj->path, (void *)*where, defobj->path));
75 break;
76
77 case R_TYPE(REL32):
78 def = _rtld_find_symdef(symnum, obj, &defobj, false);
79 if (def == NULL)
80 return -1;
81
82 tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
83 rela->r_addend) - (Elf_Addr)where;
84 if (*where != tmp)
85 *where = tmp;
86 rdbg(("PC32 %s in %s --> %p in %s",
87 obj->strtab + obj->symtab[symnum].st_name,
88 obj->path, (void *)*where, defobj->path));
89 break;
90 #endif
91
92 case R_TYPE(DIR32):
93 def = _rtld_find_symdef(symnum, obj, &defobj, false);
94 if (def == NULL)
95 return -1;
96
97 tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
98 rela->r_addend);
99 if (*where != tmp)
100 *where = tmp;
101 rdbg(("32 %s in %s --> %p in %s",
102 obj->strtab + obj->symtab[symnum].st_name,
103 obj->path, (void *)*where, defobj->path));
104 break;
105
106 case R_TYPE(GLOB_DAT):
107 def = _rtld_find_symdef(symnum, obj, &defobj, false);
108 if (def == NULL)
109 return -1;
110
111 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
112 rela->r_addend;
113 if (*where != tmp)
114 *where = tmp;
115 rdbg(("GLOB_DAT %s in %s --> %p in %s",
116 obj->strtab + obj->symtab[symnum].st_name,
117 obj->path, (void *)*where, defobj->path));
118 break;
119
120 case R_TYPE(RELATIVE):
121 if (rela->r_addend)
122 *where = (Elf_Addr)obj->relocbase + rela->r_addend;
123 else
124 *where += (Elf_Addr)obj->relocbase;
125 rdbg(("RELATIVE in %s --> %p", obj->path,
126 (void *)*where));
127 break;
128
129 case R_TYPE(COPY):
130 /*
131 * These are deferred until all other relocations have
132 * been done. All we do here is make sure that the
133 * COPY relocation is not in a shared library. They
134 * are allowed only in executable files.
135 */
136 if (obj->isdynamic) {
137 _rtld_error(
138 "%s: Unexpected R_COPY relocation in shared library",
139 obj->path);
140 return -1;
141 }
142 rdbg(("COPY (avoid in main)"));
143 break;
144
145 default:
146 rdbg(("sym = %lu, type = %lu, offset = %p, "
147 "addend = %p, contents = %p, symbol = %s",
148 symnum, (u_long)ELF_R_TYPE(rela->r_info),
149 (void *)rela->r_offset, (void *)rela->r_addend,
150 (void *)*where,
151 obj->strtab + obj->symtab[symnum].st_name));
152 _rtld_error("%s: Unsupported relocation type %ld "
153 "in non-PLT relocations\n",
154 obj->path, (u_long) ELF_R_TYPE(rela->r_info));
155 return -1;
156 }
157 }
158 return 0;
159 }
160
161 int
162 _rtld_relocate_plt_lazy(obj)
163 const Obj_Entry *obj;
164 {
165 const Elf_Rela *rela;
166
167 if (!obj->relocbase)
168 return 0;
169
170 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
171 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
172
173 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
174
175 /* Just relocate the GOT slots pointing into the PLT */
176 *where += (Elf_Addr)obj->relocbase;
177 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
178 }
179
180 return 0;
181 }
182
183 caddr_t
184 _rtld_bind(obj, reloff)
185 const Obj_Entry *obj;
186 Elf_Word reloff;
187 {
188 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
189 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
190 Elf_Addr new_value;
191 const Elf_Sym *def;
192 const Obj_Entry *defobj;
193
194 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
195
196 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
197 if (def == NULL)
198 _rtld_die();
199
200 new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
201 rdbg(("bind now/fixup in %s --> old=%p new=%p",
202 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
203 if (*where != new_value)
204 *where = new_value;
205
206 return (caddr_t)new_value;
207 }
208
209 int
210 _rtld_relocate_plt_object(obj, rela, addrp)
211 const Obj_Entry *obj;
212 const Elf_Rela *rela;
213 caddr_t *addrp;
214 {
215 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
216 Elf_Addr new_value;
217 const Elf_Sym *def;
218 const Obj_Entry *defobj;
219
220 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
221
222 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
223 if (def == NULL)
224 return -1;
225
226 new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
227 rela->r_addend);
228 rdbg(("bind now/fixup in %s --> old=%p new=%p",
229 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
230 if (*where != new_value)
231 *where = new_value;
232
233 *addrp = (caddr_t)new_value;
234 return 0;
235 }
236