mdreloc.c revision 1.16 1 1.16 mycroft /* $NetBSD: mdreloc.c,v 1.16 2002/10/03 20:39:23 mycroft 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 1.15 mycroft void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
11 1.13 mycroft caddr_t _rtld_bind __P((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 1.15 mycroft }
19 1.15 mycroft
20 1.15 mycroft void
21 1.15 mycroft _rtld_relocate_nonplt_self(dynp, relocbase)
22 1.15 mycroft Elf_Dyn *dynp;
23 1.15 mycroft Elf_Addr relocbase;
24 1.15 mycroft {
25 1.15 mycroft const Elf_Rela *rela = 0, *relalim;
26 1.15 mycroft Elf_Addr relasz = 0;
27 1.15 mycroft Elf_Addr *where;
28 1.15 mycroft
29 1.15 mycroft for (; dynp->d_tag != DT_NULL; dynp++) {
30 1.15 mycroft switch (dynp->d_tag) {
31 1.15 mycroft case DT_RELA:
32 1.15 mycroft rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
33 1.15 mycroft break;
34 1.15 mycroft case DT_RELASZ:
35 1.15 mycroft relasz = dynp->d_un.d_val;
36 1.15 mycroft break;
37 1.15 mycroft }
38 1.15 mycroft }
39 1.15 mycroft relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
40 1.15 mycroft for (; rela < relalim; rela++) {
41 1.15 mycroft where = (Elf_Addr *)(relocbase + rela->r_offset);
42 1.15 mycroft *where = (Elf_Addr)(relocbase + rela->r_addend);
43 1.15 mycroft }
44 1.1 mycroft }
45 1.2 mycroft
46 1.2 mycroft int
47 1.14 mycroft _rtld_relocate_nonplt_objects(obj)
48 1.7 mycroft const Obj_Entry *obj;
49 1.2 mycroft {
50 1.3 mycroft const Elf_Rela *rela;
51 1.2 mycroft
52 1.3 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
53 1.3 mycroft Elf_Addr *where;
54 1.3 mycroft const Elf_Sym *def;
55 1.3 mycroft const Obj_Entry *defobj;
56 1.3 mycroft Elf_Addr tmp;
57 1.4 mycroft unsigned long symnum;
58 1.3 mycroft
59 1.3 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
60 1.4 mycroft symnum = ELF_R_SYM(rela->r_info);
61 1.3 mycroft
62 1.3 mycroft switch (ELF_R_TYPE(rela->r_info)) {
63 1.3 mycroft case R_TYPE(NONE):
64 1.3 mycroft break;
65 1.3 mycroft
66 1.3 mycroft case R_TYPE(32): /* word32 S + A */
67 1.3 mycroft case R_TYPE(GLOB_DAT): /* word32 S + A */
68 1.4 mycroft def = _rtld_find_symdef(symnum, obj, &defobj, false);
69 1.3 mycroft if (def == NULL)
70 1.3 mycroft return -1;
71 1.3 mycroft
72 1.3 mycroft tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
73 1.3 mycroft rela->r_addend);
74 1.3 mycroft
75 1.3 mycroft if (*where != tmp)
76 1.3 mycroft *where = tmp;
77 1.12 mycroft rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
78 1.5 mycroft obj->strtab + obj->symtab[symnum].st_name,
79 1.5 mycroft obj->path, (void *)*where, defobj->path));
80 1.3 mycroft break;
81 1.3 mycroft
82 1.3 mycroft case R_TYPE(RELATIVE): /* word32 B + A */
83 1.3 mycroft tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
84 1.3 mycroft if (*where != tmp)
85 1.3 mycroft *where = tmp;
86 1.12 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
87 1.3 mycroft (void *)*where));
88 1.3 mycroft break;
89 1.3 mycroft
90 1.3 mycroft case R_TYPE(COPY):
91 1.3 mycroft /*
92 1.3 mycroft * These are deferred until all other relocations have
93 1.3 mycroft * been done. All we do here is make sure that the
94 1.3 mycroft * COPY relocation is not in a shared library. They
95 1.3 mycroft * are allowed only in executable files.
96 1.3 mycroft */
97 1.8 mycroft if (obj->isdynamic) {
98 1.3 mycroft _rtld_error(
99 1.2 mycroft "%s: Unexpected R_COPY relocation in shared library",
100 1.3 mycroft obj->path);
101 1.3 mycroft return -1;
102 1.3 mycroft }
103 1.12 mycroft rdbg(("COPY (avoid in main)"));
104 1.3 mycroft break;
105 1.3 mycroft
106 1.3 mycroft default:
107 1.12 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
108 1.3 mycroft "addend = %p, contents = %p, symbol = %s",
109 1.4 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
110 1.3 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
111 1.3 mycroft (void *)*where,
112 1.4 mycroft obj->strtab + obj->symtab[symnum].st_name));
113 1.3 mycroft _rtld_error("%s: Unsupported relocation type %ld "
114 1.3 mycroft "in non-PLT relocations\n",
115 1.3 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
116 1.2 mycroft return -1;
117 1.2 mycroft }
118 1.2 mycroft }
119 1.2 mycroft return 0;
120 1.2 mycroft }
121 1.6 mycroft
122 1.6 mycroft int
123 1.12 mycroft _rtld_relocate_plt_lazy(obj)
124 1.7 mycroft const Obj_Entry *obj;
125 1.6 mycroft {
126 1.6 mycroft const Elf_Rela *rela;
127 1.6 mycroft
128 1.16 mycroft if (!obj->relocbase)
129 1.6 mycroft return 0;
130 1.6 mycroft
131 1.6 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
132 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
133 1.6 mycroft
134 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
135 1.6 mycroft
136 1.6 mycroft /* Just relocate the GOT slots pointing into the PLT */
137 1.6 mycroft *where += (Elf_Addr)obj->relocbase;
138 1.12 mycroft rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
139 1.6 mycroft }
140 1.6 mycroft
141 1.6 mycroft return 0;
142 1.6 mycroft }
143 1.6 mycroft
144 1.13 mycroft caddr_t
145 1.13 mycroft _rtld_bind(obj, reloff)
146 1.7 mycroft const Obj_Entry *obj;
147 1.13 mycroft Elf_Word reloff;
148 1.6 mycroft {
149 1.13 mycroft const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff);
150 1.6 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
151 1.6 mycroft Elf_Addr new_value;
152 1.6 mycroft const Elf_Sym *def;
153 1.6 mycroft const Obj_Entry *defobj;
154 1.6 mycroft
155 1.6 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
156 1.6 mycroft
157 1.6 mycroft def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
158 1.6 mycroft if (def == NULL)
159 1.13 mycroft _rtld_die();
160 1.6 mycroft
161 1.6 mycroft new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
162 1.6 mycroft rela->r_addend);
163 1.12 mycroft rdbg(("bind now/fixup in %s --> old=%p new=%p",
164 1.6 mycroft defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
165 1.6 mycroft if (*where != new_value)
166 1.6 mycroft *where = new_value;
167 1.6 mycroft
168 1.13 mycroft return (caddr_t)(new_value - rela->r_addend);
169 1.6 mycroft }
170