mdreloc.c revision 1.17 1 1.17 tsutsui /* $NetBSD: mdreloc.c,v 1.17 2003/07/05 18:18:51 tsutsui Exp $ */
2 1.10 junyoung
3 1.1 mycroft #include <sys/types.h>
4 1.1 mycroft #include <sys/stat.h>
5 1.1 mycroft
6 1.1 mycroft #include "debug.h"
7 1.1 mycroft #include "rtld.h"
8 1.11 mycroft
9 1.11 mycroft void _rtld_bind_start(void);
10 1.17 tsutsui void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
11 1.17 tsutsui caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
12 1.17 tsutsui int _rtld_relocate_plt_object(const Obj_Entry *, const Elf_Rela *, caddr_t *);
13 1.1 mycroft
14 1.1 mycroft void
15 1.1 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
16 1.1 mycroft {
17 1.1 mycroft obj->pltgot[1] = (Elf_Addr) obj;
18 1.1 mycroft obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
19 1.1 mycroft }
20 1.2 mycroft
21 1.15 marcus void
22 1.15 marcus _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
23 1.15 marcus {
24 1.15 marcus const Elf_Rela *rela = 0, *relalim;
25 1.15 marcus Elf_Addr relasz = 0;
26 1.15 marcus Elf_Addr *where;
27 1.15 marcus
28 1.15 marcus for (; dynp->d_tag != DT_NULL; dynp++) {
29 1.15 marcus switch (dynp->d_tag) {
30 1.15 marcus case DT_RELA:
31 1.15 marcus rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
32 1.15 marcus break;
33 1.15 marcus case DT_RELASZ:
34 1.15 marcus relasz = dynp->d_un.d_val;
35 1.15 marcus break;
36 1.15 marcus }
37 1.15 marcus }
38 1.15 marcus relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
39 1.15 marcus for (; rela < relalim; rela++) {
40 1.15 marcus where = (Elf_Addr *)(relocbase + rela->r_offset);
41 1.15 marcus *where = (Elf_Addr)(relocbase + rela->r_addend);
42 1.15 marcus }
43 1.15 marcus }
44 1.15 marcus
45 1.2 mycroft int
46 1.13 mycroft _rtld_relocate_nonplt_objects(obj)
47 1.7 mycroft const Obj_Entry *obj;
48 1.2 mycroft {
49 1.3 mycroft const Elf_Rela *rela;
50 1.2 mycroft
51 1.3 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
52 1.3 mycroft Elf_Addr *where;
53 1.3 mycroft const Elf_Sym *def;
54 1.3 mycroft const Obj_Entry *defobj;
55 1.3 mycroft Elf_Addr tmp;
56 1.4 mycroft unsigned long symnum;
57 1.3 mycroft
58 1.3 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
59 1.4 mycroft symnum = ELF_R_SYM(rela->r_info);
60 1.3 mycroft
61 1.3 mycroft switch (ELF_R_TYPE(rela->r_info)) {
62 1.3 mycroft case R_TYPE(NONE):
63 1.3 mycroft break;
64 1.2 mycroft
65 1.2 mycroft #if 1 /* XXX should not occur */
66 1.3 mycroft case R_TYPE(GOT32):
67 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
68 1.3 mycroft if (def == NULL)
69 1.3 mycroft return -1;
70 1.3 mycroft
71 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
72 1.3 mycroft rela->r_addend);
73 1.3 mycroft if (*where != tmp)
74 1.3 mycroft *where = tmp;
75 1.12 mycroft rdbg(("GOT32 %s in %s --> %p in %s",
76 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
77 1.5 mycroft obj->path, (void *)*where, defobj->path));
78 1.3 mycroft break;
79 1.3 mycroft
80 1.3 mycroft case R_TYPE(REL32):
81 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
82 1.3 mycroft if (def == NULL)
83 1.3 mycroft return -1;
84 1.3 mycroft
85 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
86 1.3 mycroft rela->r_addend) - (Elf_Addr)where;
87 1.16 marcus if (*where != tmp)
88 1.16 marcus *where = tmp;
89 1.12 mycroft rdbg(("PC32 %s in %s --> %p in %s",
90 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
91 1.5 mycroft obj->path, (void *)*where, defobj->path));
92 1.3 mycroft break;
93 1.2 mycroft #endif
94 1.2 mycroft
95 1.3 mycroft case R_TYPE(DIR32):
96 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
97 1.3 mycroft if (def == NULL)
98 1.3 mycroft return -1;
99 1.3 mycroft
100 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
101 1.3 mycroft rela->r_addend);
102 1.16 marcus if (*where != tmp)
103 1.16 marcus *where = tmp;
104 1.12 mycroft rdbg(("32 %s in %s --> %p in %s",
105 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
106 1.5 mycroft obj->path, (void *)*where, defobj->path));
107 1.3 mycroft break;
108 1.3 mycroft
109 1.3 mycroft case R_TYPE(GLOB_DAT):
110 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
111 1.3 mycroft if (def == NULL)
112 1.3 mycroft return -1;
113 1.3 mycroft
114 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
115 1.3 mycroft rela->r_addend;
116 1.3 mycroft if (*where != tmp)
117 1.3 mycroft *where = tmp;
118 1.12 mycroft rdbg(("GLOB_DAT %s in %s --> %p in %s",
119 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
120 1.5 mycroft obj->path, (void *)*where, defobj->path));
121 1.3 mycroft break;
122 1.3 mycroft
123 1.3 mycroft case R_TYPE(RELATIVE):
124 1.3 mycroft if (rela->r_addend)
125 1.3 mycroft *where = (Elf_Addr)obj->relocbase + rela->r_addend;
126 1.3 mycroft else
127 1.3 mycroft *where += (Elf_Addr)obj->relocbase;
128 1.12 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
129 1.3 mycroft (void *)*where));
130 1.3 mycroft break;
131 1.3 mycroft
132 1.3 mycroft case R_TYPE(COPY):
133 1.3 mycroft /*
134 1.3 mycroft * These are deferred until all other relocations have
135 1.3 mycroft * been done. All we do here is make sure that the
136 1.3 mycroft * COPY relocation is not in a shared library. They
137 1.3 mycroft * are allowed only in executable files.
138 1.3 mycroft */
139 1.8 mycroft if (obj->isdynamic) {
140 1.3 mycroft _rtld_error(
141 1.2 mycroft "%s: Unexpected R_COPY relocation in shared library",
142 1.3 mycroft obj->path);
143 1.3 mycroft return -1;
144 1.3 mycroft }
145 1.12 mycroft rdbg(("COPY (avoid in main)"));
146 1.3 mycroft break;
147 1.3 mycroft
148 1.3 mycroft default:
149 1.12 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
150 1.3 mycroft "addend = %p, contents = %p, symbol = %s",
151 1.4 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
152 1.3 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
153 1.3 mycroft (void *)*where,
154 1.4 mycroft obj->strtab + obj->symtab[symnum].st_name));
155 1.3 mycroft _rtld_error("%s: Unsupported relocation type %ld "
156 1.3 mycroft "in non-PLT relocations\n",
157 1.3 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
158 1.2 mycroft return -1;
159 1.2 mycroft }
160 1.2 mycroft }
161 1.2 mycroft return 0;
162 1.2 mycroft }
163 1.6 mycroft
164 1.6 mycroft int
165 1.12 mycroft _rtld_relocate_plt_lazy(obj)
166 1.7 mycroft const Obj_Entry *obj;
167 1.6 mycroft {
168 1.6 mycroft const Elf_Rela *rela;
169 1.6 mycroft
170 1.14 mycroft if (!obj->relocbase)
171 1.6 mycroft return 0;
172 1.6 mycroft
173 1.6 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
174 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
175 1.6 mycroft
176 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
177 1.6 mycroft
178 1.6 mycroft /* Just relocate the GOT slots pointing into the PLT */
179 1.6 mycroft *where += (Elf_Addr)obj->relocbase;
180 1.12 mycroft rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
181 1.6 mycroft }
182 1.6 mycroft
183 1.6 mycroft return 0;
184 1.15 marcus }
185 1.15 marcus
186 1.15 marcus caddr_t
187 1.15 marcus _rtld_bind(obj, reloff)
188 1.15 marcus const Obj_Entry *obj;
189 1.15 marcus Elf_Word reloff;
190 1.15 marcus {
191 1.15 marcus const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
192 1.15 marcus Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
193 1.15 marcus Elf_Addr new_value;
194 1.15 marcus const Elf_Sym *def;
195 1.15 marcus const Obj_Entry *defobj;
196 1.15 marcus
197 1.15 marcus assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
198 1.15 marcus
199 1.15 marcus def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
200 1.15 marcus if (def == NULL)
201 1.15 marcus _rtld_die();
202 1.15 marcus
203 1.15 marcus new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
204 1.15 marcus rdbg(("bind now/fixup in %s --> old=%p new=%p",
205 1.15 marcus defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
206 1.15 marcus if (*where != new_value)
207 1.15 marcus *where = new_value;
208 1.15 marcus
209 1.15 marcus return (caddr_t)new_value;
210 1.6 mycroft }
211 1.6 mycroft
212 1.6 mycroft int
213 1.12 mycroft _rtld_relocate_plt_object(obj, rela, addrp)
214 1.7 mycroft const Obj_Entry *obj;
215 1.6 mycroft const Elf_Rela *rela;
216 1.6 mycroft caddr_t *addrp;
217 1.6 mycroft {
218 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
219 1.6 mycroft Elf_Addr new_value;
220 1.6 mycroft const Elf_Sym *def;
221 1.6 mycroft const Obj_Entry *defobj;
222 1.6 mycroft
223 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
224 1.6 mycroft
225 1.6 mycroft def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
226 1.6 mycroft if (def == NULL)
227 1.6 mycroft return -1;
228 1.6 mycroft
229 1.6 mycroft new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
230 1.6 mycroft rela->r_addend);
231 1.12 mycroft rdbg(("bind now/fixup in %s --> old=%p new=%p",
232 1.6 mycroft defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
233 1.6 mycroft if (*where != new_value)
234 1.6 mycroft *where = new_value;
235 1.6 mycroft
236 1.6 mycroft *addrp = (caddr_t)new_value;
237 1.6 mycroft return 0;
238 1.6 mycroft }
239