mdreloc.c revision 1.11 
1/*	$NetBSD: mdreloc.c,v 1.11 2002/09/11 20:45:52 mycroft Exp $	*/
2
3#include <sys/types.h>
4#include <sys/stat.h>
5
6#include "debug.h"
7#include "rtld.h"
8
9void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
10
11void
12_rtld_setup_pltgot(const Obj_Entry *obj)
13{
14	obj->pltgot[1] = (Elf_Addr) obj;
15	obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
16}
17
18void
19_rtld_relocate_nonplt_self(dynp, relocbase)
20	Elf_Dyn *dynp;
21	Elf_Addr relocbase;
22{
23	const Elf_Rela *rela = 0, *relalim;
24	Elf_Addr relasz = 0;
25	Elf_Addr *where;
26
27	for (; dynp->d_tag != DT_NULL; dynp++) {
28		switch (dynp->d_tag) {
29		case DT_RELA:
30			rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
31			break;
32		case DT_RELASZ:
33			relasz = dynp->d_un.d_val;
34			break;
35		}
36	}
37	relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
38	for (; rela < relalim; rela++) {
39		where = (Elf_Addr *)(relocbase + rela->r_offset);
40		*where += (Elf_Addr)relocbase;
41	}
42}
43
44int
45_rtld_relocate_nonplt_objects(obj, self, dodebug)
46	const Obj_Entry *obj;
47	bool self;
48	bool dodebug;
49{
50	const Elf_Rela *rela;
51
52	if (self)
53		return 0;
54
55	for (rela = obj->rela; rela < obj->relalim; rela++) {
56		Elf_Addr        *where;
57		const Elf_Sym   *def;
58		const Obj_Entry *defobj;
59		Elf_Addr         tmp;
60		unsigned long	 symnum;
61
62		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
63		symnum = ELF_R_SYM(rela->r_info);
64
65		switch (ELF_R_TYPE(rela->r_info)) {
66		case R_TYPE(NONE):
67			break;
68
69#if 1 /* XXX should not occur */
70		case R_TYPE(PC32):
71			def = _rtld_find_symdef(symnum, obj, &defobj, false);
72			if (def == NULL)
73				return -1;
74
75			tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
76			    rela->r_addend) - (Elf_Addr)where;
77			if (*where != tmp)
78				*where = tmp;
79			rdbg(dodebug, ("PC32 %s in %s --> %p in %s",
80			    obj->strtab + obj->symtab[symnum].st_name,
81			    obj->path, (void *)*where, defobj->path));
82			break;
83
84		case R_TYPE(GOT32):
85#endif
86		case R_TYPE(32):
87		case R_TYPE(GLOB_DAT):
88			def = _rtld_find_symdef(symnum, obj, &defobj, false);
89			if (def == NULL)
90				return -1;
91
92			tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
93			    rela->r_addend);
94			if (*where != tmp)
95				*where = tmp;
96			rdbg(dodebug, ("32/GLOB_DAT %s in %s --> %p in %s",
97			    obj->strtab + obj->symtab[symnum].st_name,
98			    obj->path, (void *)*where, defobj->path));
99			break;
100
101		case R_TYPE(RELATIVE):
102			*where += (Elf_Addr)obj->relocbase;
103			rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
104			    (void *)*where));
105			break;
106
107		case R_TYPE(COPY):
108			/*
109			 * These are deferred until all other relocations have
110			 * been done.  All we do here is make sure that the
111			 * COPY relocation is not in a shared library.  They
112			 * are allowed only in executable files.
113			 */
114			if (obj->isdynamic) {
115				_rtld_error(
116			"%s: Unexpected R_COPY relocation in shared library",
117				    obj->path);
118				return -1;
119			}
120			rdbg(dodebug, ("COPY (avoid in main)"));
121			break;
122
123		default:
124			rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, "
125			    "addend = %p, contents = %p, symbol = %s",
126			    symnum, (u_long)ELF_R_TYPE(rela->r_info),
127			    (void *)rela->r_offset, (void *)rela->r_addend,
128			    (void *)*where,
129			    obj->strtab + obj->symtab[symnum].st_name));
130			_rtld_error("%s: Unsupported relocation type %ld "
131			    "in non-PLT relocations\n",
132			    obj->path, (u_long) ELF_R_TYPE(rela->r_info));
133			return -1;
134		}
135	}
136	return 0;
137}
138
139int
140_rtld_relocate_plt_lazy(obj, dodebug)
141	const Obj_Entry *obj;
142	bool dodebug;
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(dodebug, ("fixup !main in %s --> %p", obj->path,
157		    (void *)*where));
158	}
159
160	return 0;
161}
162
163int
164_rtld_relocate_plt_object(obj, rela, addrp, dodebug)
165	const Obj_Entry *obj;
166	const Elf_Rela *rela;
167	caddr_t *addrp;
168	bool dodebug;
169{
170	Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
171	Elf_Addr new_value;
172	const Elf_Sym  *def;
173	const Obj_Entry *defobj;
174
175	assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
176
177	def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
178	if (def == NULL)
179		return -1;
180
181	new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
182	rdbg(dodebug, ("bind now/fixup in %s --> old=%p new=%p",
183	    defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
184	if (*where != new_value)
185		*where = new_value;
186
187	*addrp = (caddr_t)new_value;
188	return 0;
189}
190