mdreloc.c revision 1.18 1 1.18 marcus /* $NetBSD: mdreloc.c,v 1.18 2003/07/05 20:48:39 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 1.17 tsutsui void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
11 1.17 tsutsui caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
12 1.1 mycroft
13 1.1 mycroft void
14 1.1 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
15 1.1 mycroft {
16 1.1 mycroft obj->pltgot[1] = (Elf_Addr) obj;
17 1.1 mycroft obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
18 1.1 mycroft }
19 1.2 mycroft
20 1.15 marcus void
21 1.15 marcus _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
22 1.15 marcus {
23 1.15 marcus const Elf_Rela *rela = 0, *relalim;
24 1.15 marcus Elf_Addr relasz = 0;
25 1.15 marcus Elf_Addr *where;
26 1.15 marcus
27 1.15 marcus for (; dynp->d_tag != DT_NULL; dynp++) {
28 1.15 marcus switch (dynp->d_tag) {
29 1.15 marcus case DT_RELA:
30 1.15 marcus rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
31 1.15 marcus break;
32 1.15 marcus case DT_RELASZ:
33 1.15 marcus relasz = dynp->d_un.d_val;
34 1.15 marcus break;
35 1.15 marcus }
36 1.15 marcus }
37 1.15 marcus relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
38 1.15 marcus for (; rela < relalim; rela++) {
39 1.15 marcus where = (Elf_Addr *)(relocbase + rela->r_offset);
40 1.15 marcus *where = (Elf_Addr)(relocbase + rela->r_addend);
41 1.15 marcus }
42 1.15 marcus }
43 1.15 marcus
44 1.2 mycroft int
45 1.13 mycroft _rtld_relocate_nonplt_objects(obj)
46 1.7 mycroft const Obj_Entry *obj;
47 1.2 mycroft {
48 1.3 mycroft const Elf_Rela *rela;
49 1.2 mycroft
50 1.3 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
51 1.3 mycroft Elf_Addr *where;
52 1.3 mycroft const Elf_Sym *def;
53 1.3 mycroft const Obj_Entry *defobj;
54 1.3 mycroft Elf_Addr tmp;
55 1.4 mycroft unsigned long symnum;
56 1.3 mycroft
57 1.3 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
58 1.4 mycroft symnum = ELF_R_SYM(rela->r_info);
59 1.3 mycroft
60 1.3 mycroft switch (ELF_R_TYPE(rela->r_info)) {
61 1.3 mycroft case R_TYPE(NONE):
62 1.3 mycroft break;
63 1.2 mycroft
64 1.2 mycroft #if 1 /* XXX should not occur */
65 1.3 mycroft case R_TYPE(GOT32):
66 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
67 1.3 mycroft if (def == NULL)
68 1.3 mycroft return -1;
69 1.3 mycroft
70 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
71 1.3 mycroft rela->r_addend);
72 1.3 mycroft if (*where != tmp)
73 1.3 mycroft *where = tmp;
74 1.12 mycroft rdbg(("GOT32 %s in %s --> %p in %s",
75 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
76 1.5 mycroft obj->path, (void *)*where, defobj->path));
77 1.3 mycroft break;
78 1.3 mycroft
79 1.3 mycroft case R_TYPE(REL32):
80 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
81 1.3 mycroft if (def == NULL)
82 1.3 mycroft return -1;
83 1.3 mycroft
84 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
85 1.3 mycroft rela->r_addend) - (Elf_Addr)where;
86 1.16 marcus if (*where != tmp)
87 1.16 marcus *where = tmp;
88 1.12 mycroft rdbg(("PC32 %s in %s --> %p in %s",
89 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
90 1.5 mycroft obj->path, (void *)*where, defobj->path));
91 1.3 mycroft break;
92 1.2 mycroft #endif
93 1.2 mycroft
94 1.3 mycroft case R_TYPE(DIR32):
95 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
96 1.3 mycroft if (def == NULL)
97 1.3 mycroft return -1;
98 1.3 mycroft
99 1.16 marcus tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
100 1.3 mycroft rela->r_addend);
101 1.16 marcus if (*where != tmp)
102 1.16 marcus *where = tmp;
103 1.12 mycroft rdbg(("32 %s in %s --> %p in %s",
104 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
105 1.5 mycroft obj->path, (void *)*where, defobj->path));
106 1.3 mycroft break;
107 1.3 mycroft
108 1.3 mycroft case R_TYPE(GLOB_DAT):
109 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
110 1.3 mycroft if (def == NULL)
111 1.3 mycroft return -1;
112 1.3 mycroft
113 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
114 1.3 mycroft rela->r_addend;
115 1.3 mycroft if (*where != tmp)
116 1.3 mycroft *where = tmp;
117 1.12 mycroft rdbg(("GLOB_DAT %s in %s --> %p in %s",
118 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
119 1.5 mycroft obj->path, (void *)*where, defobj->path));
120 1.3 mycroft break;
121 1.3 mycroft
122 1.3 mycroft case R_TYPE(RELATIVE):
123 1.3 mycroft if (rela->r_addend)
124 1.3 mycroft *where = (Elf_Addr)obj->relocbase + rela->r_addend;
125 1.3 mycroft else
126 1.3 mycroft *where += (Elf_Addr)obj->relocbase;
127 1.12 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
128 1.3 mycroft (void *)*where));
129 1.3 mycroft break;
130 1.3 mycroft
131 1.3 mycroft case R_TYPE(COPY):
132 1.3 mycroft /*
133 1.3 mycroft * These are deferred until all other relocations have
134 1.3 mycroft * been done. All we do here is make sure that the
135 1.3 mycroft * COPY relocation is not in a shared library. They
136 1.3 mycroft * are allowed only in executable files.
137 1.3 mycroft */
138 1.8 mycroft if (obj->isdynamic) {
139 1.3 mycroft _rtld_error(
140 1.2 mycroft "%s: Unexpected R_COPY relocation in shared library",
141 1.3 mycroft obj->path);
142 1.3 mycroft return -1;
143 1.3 mycroft }
144 1.12 mycroft rdbg(("COPY (avoid in main)"));
145 1.3 mycroft break;
146 1.3 mycroft
147 1.3 mycroft default:
148 1.12 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
149 1.3 mycroft "addend = %p, contents = %p, symbol = %s",
150 1.4 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
151 1.3 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
152 1.3 mycroft (void *)*where,
153 1.4 mycroft obj->strtab + obj->symtab[symnum].st_name));
154 1.3 mycroft _rtld_error("%s: Unsupported relocation type %ld "
155 1.3 mycroft "in non-PLT relocations\n",
156 1.3 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
157 1.2 mycroft return -1;
158 1.2 mycroft }
159 1.2 mycroft }
160 1.2 mycroft return 0;
161 1.2 mycroft }
162 1.6 mycroft
163 1.6 mycroft int
164 1.12 mycroft _rtld_relocate_plt_lazy(obj)
165 1.7 mycroft const Obj_Entry *obj;
166 1.6 mycroft {
167 1.6 mycroft const Elf_Rela *rela;
168 1.6 mycroft
169 1.14 mycroft if (!obj->relocbase)
170 1.6 mycroft return 0;
171 1.6 mycroft
172 1.6 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
173 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
174 1.6 mycroft
175 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
176 1.6 mycroft
177 1.6 mycroft /* Just relocate the GOT slots pointing into the PLT */
178 1.6 mycroft *where += (Elf_Addr)obj->relocbase;
179 1.12 mycroft rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
180 1.6 mycroft }
181 1.6 mycroft
182 1.6 mycroft return 0;
183 1.15 marcus }
184 1.15 marcus
185 1.15 marcus caddr_t
186 1.15 marcus _rtld_bind(obj, reloff)
187 1.15 marcus const Obj_Entry *obj;
188 1.15 marcus Elf_Word reloff;
189 1.15 marcus {
190 1.15 marcus const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
191 1.15 marcus Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
192 1.15 marcus Elf_Addr new_value;
193 1.15 marcus const Elf_Sym *def;
194 1.15 marcus const Obj_Entry *defobj;
195 1.15 marcus
196 1.15 marcus assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
197 1.15 marcus
198 1.15 marcus def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
199 1.15 marcus if (def == NULL)
200 1.15 marcus _rtld_die();
201 1.15 marcus
202 1.15 marcus new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
203 1.15 marcus rdbg(("bind now/fixup in %s --> old=%p new=%p",
204 1.15 marcus defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
205 1.15 marcus if (*where != new_value)
206 1.15 marcus *where = new_value;
207 1.15 marcus
208 1.15 marcus return (caddr_t)new_value;
209 1.6 mycroft }
210 1.6 mycroft
211