mdreloc.c revision 1.12 1 /* $NetBSD: mdreloc.c,v 1.12 2002/09/12 20:21:00 mycroft 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 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
11
12 void
13 _rtld_setup_pltgot(const Obj_Entry *obj)
14 {
15 obj->pltgot[1] = (Elf_Addr) obj;
16 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
17 }
18
19 void
20 _rtld_relocate_nonplt_self(dynp, relocbase)
21 Elf_Dyn *dynp;
22 Elf_Addr relocbase;
23 {
24 const Elf_Rela *rela = 0, *relalim;
25 Elf_Addr relasz = 0;
26 Elf_Addr *where;
27
28 for (; dynp->d_tag != DT_NULL; dynp++) {
29 switch (dynp->d_tag) {
30 case DT_RELA:
31 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
32 break;
33 case DT_RELASZ:
34 relasz = dynp->d_un.d_val;
35 break;
36 }
37 }
38 relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
39 for (; rela < relalim; rela++) {
40 where = (Elf_Addr *)(relocbase + rela->r_offset);
41 *where += (Elf_Addr)relocbase;
42 }
43 }
44
45 int
46 _rtld_relocate_nonplt_objects(obj, self, dodebug)
47 const Obj_Entry *obj;
48 bool self;
49 bool dodebug;
50 {
51 const Elf_Rela *rela;
52
53 if (self)
54 return 0;
55
56 for (rela = obj->rela; rela < obj->relalim; rela++) {
57 Elf_Addr *where;
58 const Elf_Sym *def;
59 const Obj_Entry *defobj;
60 Elf_Addr tmp;
61 unsigned long symnum;
62
63 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
64 symnum = ELF_R_SYM(rela->r_info);
65
66 switch (ELF_R_TYPE(rela->r_info)) {
67 case R_TYPE(NONE):
68 break;
69
70 #if 1 /* XXX should not occur */
71 case R_TYPE(PC32):
72 def = _rtld_find_symdef(symnum, obj, &defobj, false);
73 if (def == NULL)
74 return -1;
75
76 tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
77 rela->r_addend) - (Elf_Addr)where;
78 if (*where != tmp)
79 *where = tmp;
80 rdbg(dodebug, ("PC32 %s in %s --> %p in %s",
81 obj->strtab + obj->symtab[symnum].st_name,
82 obj->path, (void *)*where, defobj->path));
83 break;
84
85 case R_TYPE(GOT32):
86 #endif
87 case R_TYPE(32):
88 case R_TYPE(GLOB_DAT):
89 def = _rtld_find_symdef(symnum, obj, &defobj, false);
90 if (def == NULL)
91 return -1;
92
93 tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
94 rela->r_addend);
95 if (*where != tmp)
96 *where = tmp;
97 rdbg(dodebug, ("32/GLOB_DAT %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(RELATIVE):
103 *where += (Elf_Addr)obj->relocbase;
104 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
105 (void *)*where));
106 break;
107
108 case R_TYPE(COPY):
109 /*
110 * These are deferred until all other relocations have
111 * been done. All we do here is make sure that the
112 * COPY relocation is not in a shared library. They
113 * are allowed only in executable files.
114 */
115 if (obj->isdynamic) {
116 _rtld_error(
117 "%s: Unexpected R_COPY relocation in shared library",
118 obj->path);
119 return -1;
120 }
121 rdbg(dodebug, ("COPY (avoid in main)"));
122 break;
123
124 default:
125 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, "
126 "addend = %p, contents = %p, symbol = %s",
127 symnum, (u_long)ELF_R_TYPE(rela->r_info),
128 (void *)rela->r_offset, (void *)rela->r_addend,
129 (void *)*where,
130 obj->strtab + obj->symtab[symnum].st_name));
131 _rtld_error("%s: Unsupported relocation type %ld "
132 "in non-PLT relocations\n",
133 obj->path, (u_long) ELF_R_TYPE(rela->r_info));
134 return -1;
135 }
136 }
137 return 0;
138 }
139
140 int
141 _rtld_relocate_plt_lazy(obj, dodebug)
142 const Obj_Entry *obj;
143 bool dodebug;
144 {
145 const Elf_Rela *rela;
146
147 if (!obj->isdynamic)
148 return 0;
149
150 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
151 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
152
153 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
154
155 /* Just relocate the GOT slots pointing into the PLT */
156 *where += (Elf_Addr)obj->relocbase;
157 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path,
158 (void *)*where));
159 }
160
161 return 0;
162 }
163
164 int
165 _rtld_relocate_plt_object(obj, rela, addrp, dodebug)
166 const Obj_Entry *obj;
167 const Elf_Rela *rela;
168 caddr_t *addrp;
169 bool dodebug;
170 {
171 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
172 Elf_Addr new_value;
173 const Elf_Sym *def;
174 const Obj_Entry *defobj;
175
176 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
177
178 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
179 if (def == NULL)
180 return -1;
181
182 new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
183 rdbg(dodebug, ("bind now/fixup in %s --> old=%p new=%p",
184 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
185 if (*where != new_value)
186 *where = new_value;
187
188 *addrp = (caddr_t)new_value;
189 return 0;
190 }
191