mdreloc.c revision 1.15 1 /* $NetBSD: mdreloc.c,v 1.15 2003/06/30 00:50:46 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 *where += (Elf_Addr)(defobj->relocbase + def->st_value +
83 rela->r_addend) - (Elf_Addr)where;
84 rdbg(("PC32 %s in %s --> %p in %s",
85 obj->strtab + obj->symtab[symnum].st_name,
86 obj->path, (void *)*where, defobj->path));
87 break;
88 #endif
89
90 case R_TYPE(DIR32):
91 def = _rtld_find_symdef(symnum, obj, &defobj, false);
92 if (def == NULL)
93 return -1;
94
95 *where += (Elf_Addr)(defobj->relocbase + def->st_value +
96 rela->r_addend);
97 rdbg(("32 %s in %s --> %p in %s",
98 obj->strtab + obj->symtab[symnum].st_name,
99 obj->path, (void *)*where, defobj->path));
100 break;
101
102 case R_TYPE(GLOB_DAT):
103 def = _rtld_find_symdef(symnum, obj, &defobj, false);
104 if (def == NULL)
105 return -1;
106
107 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
108 rela->r_addend;
109 if (*where != tmp)
110 *where = tmp;
111 rdbg(("GLOB_DAT %s in %s --> %p in %s",
112 obj->strtab + obj->symtab[symnum].st_name,
113 obj->path, (void *)*where, defobj->path));
114 break;
115
116 case R_TYPE(RELATIVE):
117 if (rela->r_addend)
118 *where = (Elf_Addr)obj->relocbase + rela->r_addend;
119 else
120 *where += (Elf_Addr)obj->relocbase;
121 rdbg(("RELATIVE in %s --> %p", obj->path,
122 (void *)*where));
123 break;
124
125 case R_TYPE(COPY):
126 /*
127 * These are deferred until all other relocations have
128 * been done. All we do here is make sure that the
129 * COPY relocation is not in a shared library. They
130 * are allowed only in executable files.
131 */
132 if (obj->isdynamic) {
133 _rtld_error(
134 "%s: Unexpected R_COPY relocation in shared library",
135 obj->path);
136 return -1;
137 }
138 rdbg(("COPY (avoid in main)"));
139 break;
140
141 default:
142 rdbg(("sym = %lu, type = %lu, offset = %p, "
143 "addend = %p, contents = %p, symbol = %s",
144 symnum, (u_long)ELF_R_TYPE(rela->r_info),
145 (void *)rela->r_offset, (void *)rela->r_addend,
146 (void *)*where,
147 obj->strtab + obj->symtab[symnum].st_name));
148 _rtld_error("%s: Unsupported relocation type %ld "
149 "in non-PLT relocations\n",
150 obj->path, (u_long) ELF_R_TYPE(rela->r_info));
151 return -1;
152 }
153 }
154 return 0;
155 }
156
157 int
158 _rtld_relocate_plt_lazy(obj)
159 const Obj_Entry *obj;
160 {
161 const Elf_Rela *rela;
162
163 if (!obj->relocbase)
164 return 0;
165
166 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
167 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
168
169 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
170
171 /* Just relocate the GOT slots pointing into the PLT */
172 *where += (Elf_Addr)obj->relocbase;
173 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
174 }
175
176 return 0;
177 }
178
179 caddr_t
180 _rtld_bind(obj, reloff)
181 const Obj_Entry *obj;
182 Elf_Word reloff;
183 {
184 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
185 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
186 Elf_Addr new_value;
187 const Elf_Sym *def;
188 const Obj_Entry *defobj;
189
190 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
191
192 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
193 if (def == NULL)
194 _rtld_die();
195
196 new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
197 rdbg(("bind now/fixup in %s --> old=%p new=%p",
198 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
199 if (*where != new_value)
200 *where = new_value;
201
202 return (caddr_t)new_value;
203 }
204
205 int
206 _rtld_relocate_plt_object(obj, rela, addrp)
207 const Obj_Entry *obj;
208 const Elf_Rela *rela;
209 caddr_t *addrp;
210 {
211 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
212 Elf_Addr new_value;
213 const Elf_Sym *def;
214 const Obj_Entry *defobj;
215
216 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
217
218 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
219 if (def == NULL)
220 return -1;
221
222 new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
223 rela->r_addend);
224 rdbg(("bind now/fixup in %s --> old=%p new=%p",
225 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
226 if (*where != new_value)
227 *where = new_value;
228
229 *addrp = (caddr_t)new_value;
230 return 0;
231 }
232