mdreloc.c revision 1.22 1 1.22 mrg /* $NetBSD: mdreloc.c,v 1.22 2006/05/21 04:17:35 mrg Exp $ */
2 1.21 skrll
3 1.21 skrll #include <sys/cdefs.h>
4 1.21 skrll #ifndef lint
5 1.22 mrg __RCSID("$NetBSD: mdreloc.c,v 1.22 2006/05/21 04:17:35 mrg Exp $");
6 1.21 skrll #endif /* not lint */
7 1.10 junyoung
8 1.1 mycroft #include <sys/types.h>
9 1.1 mycroft #include <sys/stat.h>
10 1.1 mycroft
11 1.1 mycroft #include "debug.h"
12 1.1 mycroft #include "rtld.h"
13 1.11 mycroft
14 1.11 mycroft void _rtld_bind_start(void);
15 1.17 tsutsui void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
16 1.17 tsutsui caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
17 1.20 skrll static inline int _rtld_relocate_plt_object(const Obj_Entry *,
18 1.20 skrll const Elf_Rela *, Elf_Addr *);
19 1.1 mycroft
20 1.1 mycroft void
21 1.1 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
22 1.1 mycroft {
23 1.1 mycroft obj->pltgot[1] = (Elf_Addr) obj;
24 1.1 mycroft obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
25 1.1 mycroft }
26 1.2 mycroft
27 1.15 marcus void
28 1.15 marcus _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
29 1.15 marcus {
30 1.15 marcus const Elf_Rela *rela = 0, *relalim;
31 1.15 marcus Elf_Addr relasz = 0;
32 1.15 marcus Elf_Addr *where;
33 1.15 marcus
34 1.15 marcus for (; dynp->d_tag != DT_NULL; dynp++) {
35 1.15 marcus switch (dynp->d_tag) {
36 1.15 marcus case DT_RELA:
37 1.15 marcus rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
38 1.15 marcus break;
39 1.15 marcus case DT_RELASZ:
40 1.15 marcus relasz = dynp->d_un.d_val;
41 1.15 marcus break;
42 1.15 marcus }
43 1.15 marcus }
44 1.15 marcus relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
45 1.15 marcus for (; rela < relalim; rela++) {
46 1.15 marcus where = (Elf_Addr *)(relocbase + rela->r_offset);
47 1.15 marcus *where = (Elf_Addr)(relocbase + rela->r_addend);
48 1.15 marcus }
49 1.15 marcus }
50 1.15 marcus
51 1.2 mycroft int
52 1.19 skrll _rtld_relocate_nonplt_objects(const Obj_Entry *obj)
53 1.2 mycroft {
54 1.3 mycroft const Elf_Rela *rela;
55 1.2 mycroft
56 1.3 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
57 1.3 mycroft Elf_Addr *where;
58 1.3 mycroft const Elf_Sym *def;
59 1.3 mycroft const Obj_Entry *defobj;
60 1.3 mycroft Elf_Addr tmp;
61 1.4 mycroft unsigned long symnum;
62 1.3 mycroft
63 1.3 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
64 1.4 mycroft symnum = ELF_R_SYM(rela->r_info);
65 1.3 mycroft
66 1.3 mycroft switch (ELF_R_TYPE(rela->r_info)) {
67 1.3 mycroft case R_TYPE(NONE):
68 1.3 mycroft break;
69 1.2 mycroft
70 1.2 mycroft #if 1 /* XXX should not occur */
71 1.3 mycroft case R_TYPE(GOT32):
72 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
73 1.3 mycroft if (def == NULL)
74 1.3 mycroft return -1;
75 1.3 mycroft
76 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
77 1.3 mycroft rela->r_addend);
78 1.3 mycroft if (*where != tmp)
79 1.3 mycroft *where = tmp;
80 1.12 mycroft rdbg(("GOT32 %s in %s --> %p in %s",
81 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
82 1.5 mycroft obj->path, (void *)*where, defobj->path));
83 1.3 mycroft break;
84 1.3 mycroft
85 1.3 mycroft case R_TYPE(REL32):
86 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
87 1.3 mycroft if (def == NULL)
88 1.3 mycroft return -1;
89 1.3 mycroft
90 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
91 1.3 mycroft rela->r_addend) - (Elf_Addr)where;
92 1.16 marcus if (*where != tmp)
93 1.16 marcus *where = tmp;
94 1.12 mycroft rdbg(("PC32 %s in %s --> %p in %s",
95 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
96 1.5 mycroft obj->path, (void *)*where, defobj->path));
97 1.3 mycroft break;
98 1.2 mycroft #endif
99 1.2 mycroft
100 1.3 mycroft case R_TYPE(DIR32):
101 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
102 1.3 mycroft if (def == NULL)
103 1.3 mycroft return -1;
104 1.3 mycroft
105 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
106 1.3 mycroft rela->r_addend);
107 1.16 marcus if (*where != tmp)
108 1.16 marcus *where = tmp;
109 1.12 mycroft rdbg(("32 %s in %s --> %p in %s",
110 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
111 1.5 mycroft obj->path, (void *)*where, defobj->path));
112 1.3 mycroft break;
113 1.3 mycroft
114 1.3 mycroft case R_TYPE(GLOB_DAT):
115 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
116 1.3 mycroft if (def == NULL)
117 1.3 mycroft return -1;
118 1.3 mycroft
119 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
120 1.3 mycroft rela->r_addend;
121 1.3 mycroft if (*where != tmp)
122 1.3 mycroft *where = tmp;
123 1.12 mycroft rdbg(("GLOB_DAT %s in %s --> %p in %s",
124 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
125 1.5 mycroft obj->path, (void *)*where, defobj->path));
126 1.3 mycroft break;
127 1.3 mycroft
128 1.3 mycroft case R_TYPE(RELATIVE):
129 1.3 mycroft if (rela->r_addend)
130 1.3 mycroft *where = (Elf_Addr)obj->relocbase + rela->r_addend;
131 1.3 mycroft else
132 1.3 mycroft *where += (Elf_Addr)obj->relocbase;
133 1.12 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
134 1.3 mycroft (void *)*where));
135 1.3 mycroft break;
136 1.3 mycroft
137 1.3 mycroft case R_TYPE(COPY):
138 1.3 mycroft /*
139 1.3 mycroft * These are deferred until all other relocations have
140 1.3 mycroft * been done. All we do here is make sure that the
141 1.3 mycroft * COPY relocation is not in a shared library. They
142 1.3 mycroft * are allowed only in executable files.
143 1.3 mycroft */
144 1.8 mycroft if (obj->isdynamic) {
145 1.3 mycroft _rtld_error(
146 1.2 mycroft "%s: Unexpected R_COPY relocation in shared library",
147 1.3 mycroft obj->path);
148 1.3 mycroft return -1;
149 1.3 mycroft }
150 1.12 mycroft rdbg(("COPY (avoid in main)"));
151 1.3 mycroft break;
152 1.3 mycroft
153 1.3 mycroft default:
154 1.12 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
155 1.3 mycroft "addend = %p, contents = %p, symbol = %s",
156 1.4 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
157 1.3 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
158 1.3 mycroft (void *)*where,
159 1.4 mycroft obj->strtab + obj->symtab[symnum].st_name));
160 1.3 mycroft _rtld_error("%s: Unsupported relocation type %ld "
161 1.3 mycroft "in non-PLT relocations\n",
162 1.3 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
163 1.2 mycroft return -1;
164 1.2 mycroft }
165 1.2 mycroft }
166 1.2 mycroft return 0;
167 1.2 mycroft }
168 1.6 mycroft
169 1.6 mycroft int
170 1.19 skrll _rtld_relocate_plt_lazy(const Obj_Entry *obj)
171 1.6 mycroft {
172 1.6 mycroft const Elf_Rela *rela;
173 1.6 mycroft
174 1.14 mycroft if (!obj->relocbase)
175 1.6 mycroft return 0;
176 1.6 mycroft
177 1.6 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
178 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
179 1.6 mycroft
180 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
181 1.6 mycroft
182 1.6 mycroft /* Just relocate the GOT slots pointing into the PLT */
183 1.6 mycroft *where += (Elf_Addr)obj->relocbase;
184 1.12 mycroft rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
185 1.6 mycroft }
186 1.6 mycroft
187 1.6 mycroft return 0;
188 1.15 marcus }
189 1.15 marcus
190 1.15 marcus caddr_t
191 1.19 skrll _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
192 1.15 marcus {
193 1.15 marcus const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
194 1.20 skrll Elf_Addr new_value;
195 1.20 skrll int err;
196 1.20 skrll
197 1.22 mrg new_value = 0; /* XXX gcc */
198 1.22 mrg
199 1.20 skrll err = _rtld_relocate_plt_object(obj, rela, &new_value);
200 1.20 skrll if (err)
201 1.20 skrll _rtld_die();
202 1.20 skrll
203 1.20 skrll return (caddr_t)new_value;
204 1.20 skrll }
205 1.20 skrll
206 1.20 skrll int
207 1.20 skrll _rtld_relocate_plt_objects(const Obj_Entry *obj)
208 1.20 skrll {
209 1.20 skrll const Elf_Rela *rela = obj->pltrela;
210 1.20 skrll
211 1.20 skrll for (; rela < obj->pltrelalim; rela++)
212 1.20 skrll if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
213 1.20 skrll return -1;
214 1.20 skrll
215 1.20 skrll return 0;
216 1.20 skrll }
217 1.20 skrll
218 1.20 skrll static inline int
219 1.20 skrll _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *tp)
220 1.20 skrll {
221 1.15 marcus Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
222 1.15 marcus Elf_Addr new_value;
223 1.15 marcus const Elf_Sym *def;
224 1.15 marcus const Obj_Entry *defobj;
225 1.15 marcus
226 1.15 marcus assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
227 1.15 marcus
228 1.15 marcus def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
229 1.15 marcus if (def == NULL)
230 1.20 skrll return -1;
231 1.15 marcus
232 1.15 marcus new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
233 1.15 marcus rdbg(("bind now/fixup in %s --> old=%p new=%p",
234 1.15 marcus defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
235 1.15 marcus if (*where != new_value)
236 1.15 marcus *where = new_value;
237 1.15 marcus
238 1.20 skrll if (tp)
239 1.20 skrll *tp = new_value;
240 1.20 skrll
241 1.20 skrll return 0;
242 1.6 mycroft }
243