mdreloc.c revision 1.16 1 1.16 marcus /* $NetBSD: mdreloc.c,v 1.16 2003/07/02 15:29:34 marcus 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 1.1 mycroft
11 1.1 mycroft void
12 1.1 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
13 1.1 mycroft {
14 1.1 mycroft obj->pltgot[1] = (Elf_Addr) obj;
15 1.1 mycroft obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
16 1.1 mycroft }
17 1.2 mycroft
18 1.15 marcus void
19 1.15 marcus _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
20 1.15 marcus {
21 1.15 marcus const Elf_Rela *rela = 0, *relalim;
22 1.15 marcus Elf_Addr relasz = 0;
23 1.15 marcus Elf_Addr *where;
24 1.15 marcus
25 1.15 marcus for (; dynp->d_tag != DT_NULL; dynp++) {
26 1.15 marcus switch (dynp->d_tag) {
27 1.15 marcus case DT_RELA:
28 1.15 marcus rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
29 1.15 marcus break;
30 1.15 marcus case DT_RELASZ:
31 1.15 marcus relasz = dynp->d_un.d_val;
32 1.15 marcus break;
33 1.15 marcus }
34 1.15 marcus }
35 1.15 marcus relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
36 1.15 marcus for (; rela < relalim; rela++) {
37 1.15 marcus where = (Elf_Addr *)(relocbase + rela->r_offset);
38 1.15 marcus *where = (Elf_Addr)(relocbase + rela->r_addend);
39 1.15 marcus }
40 1.15 marcus }
41 1.15 marcus
42 1.2 mycroft int
43 1.13 mycroft _rtld_relocate_nonplt_objects(obj)
44 1.7 mycroft const Obj_Entry *obj;
45 1.2 mycroft {
46 1.3 mycroft const Elf_Rela *rela;
47 1.2 mycroft
48 1.3 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
49 1.3 mycroft Elf_Addr *where;
50 1.3 mycroft const Elf_Sym *def;
51 1.3 mycroft const Obj_Entry *defobj;
52 1.3 mycroft Elf_Addr tmp;
53 1.4 mycroft unsigned long symnum;
54 1.3 mycroft
55 1.3 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
56 1.4 mycroft symnum = ELF_R_SYM(rela->r_info);
57 1.3 mycroft
58 1.3 mycroft switch (ELF_R_TYPE(rela->r_info)) {
59 1.3 mycroft case R_TYPE(NONE):
60 1.3 mycroft break;
61 1.2 mycroft
62 1.2 mycroft #if 1 /* XXX should not occur */
63 1.3 mycroft case R_TYPE(GOT32):
64 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
65 1.3 mycroft if (def == NULL)
66 1.3 mycroft return -1;
67 1.3 mycroft
68 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
69 1.3 mycroft rela->r_addend);
70 1.3 mycroft if (*where != tmp)
71 1.3 mycroft *where = tmp;
72 1.12 mycroft rdbg(("GOT32 %s in %s --> %p in %s",
73 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
74 1.5 mycroft obj->path, (void *)*where, defobj->path));
75 1.3 mycroft break;
76 1.3 mycroft
77 1.3 mycroft case R_TYPE(REL32):
78 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
79 1.3 mycroft if (def == NULL)
80 1.3 mycroft return -1;
81 1.3 mycroft
82 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
83 1.3 mycroft rela->r_addend) - (Elf_Addr)where;
84 1.16 marcus if (*where != tmp)
85 1.16 marcus *where = tmp;
86 1.12 mycroft rdbg(("PC32 %s in %s --> %p in %s",
87 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
88 1.5 mycroft obj->path, (void *)*where, defobj->path));
89 1.3 mycroft break;
90 1.2 mycroft #endif
91 1.2 mycroft
92 1.3 mycroft case R_TYPE(DIR32):
93 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
94 1.3 mycroft if (def == NULL)
95 1.3 mycroft return -1;
96 1.3 mycroft
97 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
98 1.3 mycroft rela->r_addend);
99 1.16 marcus if (*where != tmp)
100 1.16 marcus *where = tmp;
101 1.12 mycroft rdbg(("32 %s in %s --> %p in %s",
102 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
103 1.5 mycroft obj->path, (void *)*where, defobj->path));
104 1.3 mycroft break;
105 1.3 mycroft
106 1.3 mycroft case R_TYPE(GLOB_DAT):
107 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
108 1.3 mycroft if (def == NULL)
109 1.3 mycroft return -1;
110 1.3 mycroft
111 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
112 1.3 mycroft rela->r_addend;
113 1.3 mycroft if (*where != tmp)
114 1.3 mycroft *where = tmp;
115 1.12 mycroft rdbg(("GLOB_DAT %s in %s --> %p in %s",
116 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
117 1.5 mycroft obj->path, (void *)*where, defobj->path));
118 1.3 mycroft break;
119 1.3 mycroft
120 1.3 mycroft case R_TYPE(RELATIVE):
121 1.3 mycroft if (rela->r_addend)
122 1.3 mycroft *where = (Elf_Addr)obj->relocbase + rela->r_addend;
123 1.3 mycroft else
124 1.3 mycroft *where += (Elf_Addr)obj->relocbase;
125 1.12 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
126 1.3 mycroft (void *)*where));
127 1.3 mycroft break;
128 1.3 mycroft
129 1.3 mycroft case R_TYPE(COPY):
130 1.3 mycroft /*
131 1.3 mycroft * These are deferred until all other relocations have
132 1.3 mycroft * been done. All we do here is make sure that the
133 1.3 mycroft * COPY relocation is not in a shared library. They
134 1.3 mycroft * are allowed only in executable files.
135 1.3 mycroft */
136 1.8 mycroft if (obj->isdynamic) {
137 1.3 mycroft _rtld_error(
138 1.2 mycroft "%s: Unexpected R_COPY relocation in shared library",
139 1.3 mycroft obj->path);
140 1.3 mycroft return -1;
141 1.3 mycroft }
142 1.12 mycroft rdbg(("COPY (avoid in main)"));
143 1.3 mycroft break;
144 1.3 mycroft
145 1.3 mycroft default:
146 1.12 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
147 1.3 mycroft "addend = %p, contents = %p, symbol = %s",
148 1.4 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
149 1.3 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
150 1.3 mycroft (void *)*where,
151 1.4 mycroft obj->strtab + obj->symtab[symnum].st_name));
152 1.3 mycroft _rtld_error("%s: Unsupported relocation type %ld "
153 1.3 mycroft "in non-PLT relocations\n",
154 1.3 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
155 1.2 mycroft return -1;
156 1.2 mycroft }
157 1.2 mycroft }
158 1.2 mycroft return 0;
159 1.2 mycroft }
160 1.6 mycroft
161 1.6 mycroft int
162 1.12 mycroft _rtld_relocate_plt_lazy(obj)
163 1.7 mycroft const Obj_Entry *obj;
164 1.6 mycroft {
165 1.6 mycroft const Elf_Rela *rela;
166 1.6 mycroft
167 1.14 mycroft if (!obj->relocbase)
168 1.6 mycroft return 0;
169 1.6 mycroft
170 1.6 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
171 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
172 1.6 mycroft
173 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
174 1.6 mycroft
175 1.6 mycroft /* Just relocate the GOT slots pointing into the PLT */
176 1.6 mycroft *where += (Elf_Addr)obj->relocbase;
177 1.12 mycroft rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
178 1.6 mycroft }
179 1.6 mycroft
180 1.6 mycroft return 0;
181 1.15 marcus }
182 1.15 marcus
183 1.15 marcus caddr_t
184 1.15 marcus _rtld_bind(obj, reloff)
185 1.15 marcus const Obj_Entry *obj;
186 1.15 marcus Elf_Word reloff;
187 1.15 marcus {
188 1.15 marcus const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
189 1.15 marcus Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
190 1.15 marcus Elf_Addr new_value;
191 1.15 marcus const Elf_Sym *def;
192 1.15 marcus const Obj_Entry *defobj;
193 1.15 marcus
194 1.15 marcus assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
195 1.15 marcus
196 1.15 marcus def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
197 1.15 marcus if (def == NULL)
198 1.15 marcus _rtld_die();
199 1.15 marcus
200 1.15 marcus new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
201 1.15 marcus rdbg(("bind now/fixup in %s --> old=%p new=%p",
202 1.15 marcus defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
203 1.15 marcus if (*where != new_value)
204 1.15 marcus *where = new_value;
205 1.15 marcus
206 1.15 marcus return (caddr_t)new_value;
207 1.6 mycroft }
208 1.6 mycroft
209 1.6 mycroft int
210 1.12 mycroft _rtld_relocate_plt_object(obj, rela, addrp)
211 1.7 mycroft const Obj_Entry *obj;
212 1.6 mycroft const Elf_Rela *rela;
213 1.6 mycroft caddr_t *addrp;
214 1.6 mycroft {
215 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
216 1.6 mycroft Elf_Addr new_value;
217 1.6 mycroft const Elf_Sym *def;
218 1.6 mycroft const Obj_Entry *defobj;
219 1.6 mycroft
220 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
221 1.6 mycroft
222 1.6 mycroft def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
223 1.6 mycroft if (def == NULL)
224 1.6 mycroft return -1;
225 1.6 mycroft
226 1.6 mycroft new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
227 1.6 mycroft rela->r_addend);
228 1.12 mycroft rdbg(("bind now/fixup in %s --> old=%p new=%p",
229 1.6 mycroft defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
230 1.6 mycroft if (*where != new_value)
231 1.6 mycroft *where = new_value;
232 1.6 mycroft
233 1.6 mycroft *addrp = (caddr_t)new_value;
234 1.6 mycroft return 0;
235 1.6 mycroft }
236