mdreloc.c revision 1.14 1 /* $NetBSD: mdreloc.c,v 1.14 2002/09/25 07:27:52 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 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word));
12
13 void
14 _rtld_setup_pltgot(const Obj_Entry *obj)
15 {
16 obj->pltgot[1] = (Elf_Addr) obj;
17 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
18 }
19
20 void
21 _rtld_relocate_nonplt_self(dynp, relocbase)
22 Elf_Dyn *dynp;
23 Elf_Addr relocbase;
24 {
25 const Elf_Rela *rela = 0, *relalim;
26 Elf_Addr relasz = 0;
27 Elf_Addr *where;
28
29 for (; dynp->d_tag != DT_NULL; dynp++) {
30 switch (dynp->d_tag) {
31 case DT_RELA:
32 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
33 break;
34 case DT_RELASZ:
35 relasz = dynp->d_un.d_val;
36 break;
37 }
38 }
39 relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
40 for (; rela < relalim; rela++) {
41 where = (Elf_Addr *)(relocbase + rela->r_offset);
42 *where += (Elf_Addr)relocbase;
43 }
44 }
45
46 int
47 _rtld_relocate_nonplt_objects(obj, self)
48 const Obj_Entry *obj;
49 bool self;
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(("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(("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(("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(("COPY (avoid in main)"));
122 break;
123
124 default:
125 rdbg(("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)
142 const Obj_Entry *obj;
143 {
144 const Elf_Rela *rela;
145
146 if (!obj->isdynamic)
147 return 0;
148
149 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
150 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
151
152 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
153
154 /* Just relocate the GOT slots pointing into the PLT */
155 *where += (Elf_Addr)obj->relocbase;
156 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
157 }
158
159 return 0;
160 }
161
162 caddr_t
163 _rtld_bind(obj, reloff)
164 const Obj_Entry *obj;
165 Elf_Word reloff;
166 {
167 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
168 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
169 Elf_Addr new_value;
170 const Elf_Sym *def;
171 const Obj_Entry *defobj;
172
173 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
174
175 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
176 if (def == NULL)
177 _rtld_die();
178
179 new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
180 rdbg(("bind now/fixup in %s --> old=%p new=%p",
181 defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
182 if (*where != new_value)
183 *where = new_value;
184
185 return (caddr_t)new_value;
186 }
187