1 /* vi: set sw=4 ts=4: */
2 /* m68k ELF shared library loader suppport
4 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
5 * David Engel, Hongjiu Lu and Mitch D'Souza
6 * Adapted to ELF/68k by Andreas Schwab.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. The name of the above contributors may not be
16 * used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 /* Program to load an ELF binary on a linux system, and run it.
33 References to symbols in sharable libraries can be resolved by either
34 an ELF sharable library or a linux style of shared library. */
36 /* Disclaimer: I have never seen any AT&T source code for SVr4, nor have
37 I ever taken any courses on internals. This program was developed using
38 information available through the book "UNIX SYSTEM V RELEASE 4,
39 Programmers guide: Ansi C and Programming Support Tools", which did
40 a more than adequate job of explaining everything required to get this
45 extern int _dl_linux_resolve(void);
48 _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
51 ELF_RELOC *this_reloc;
58 ElfW(Addr) instr_addr;
61 rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
62 this_reloc = (ELF_RELOC *)(rel_addr + reloc_entry);
63 reloc_type = ELF_R_TYPE(this_reloc->r_info);
64 symtab_index = ELF_R_SYM(this_reloc->r_info);
66 symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
67 strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
68 symname = strtab + symtab[symtab_index].st_name;
70 if (unlikely(reloc_type != R_68K_JMP_SLOT)) {
71 _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
76 /* Address of the jump instruction to fix up. */
77 instr_addr = (this_reloc->r_offset + tpnt->loadaddr);
78 got_addr = (char **)instr_addr;
80 /* Get the address of the GOT entry. */
81 new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
82 if (unlikely(!new_addr)) {
83 _dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname);
87 #if defined (__SUPPORT_LD_DEBUG__)
88 if ((unsigned long)got_addr < 0x40000000) {
89 if (_dl_debug_bindings) {
90 _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
92 _dl_dprintf(_dl_debug_file,
93 "\tpatched: %x ==> %x @ %x\n",
94 *got_addr, new_addr, got_addr);
97 if (!_dl_debug_nofixups)
101 return (unsigned int)new_addr;
105 _dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
106 unsigned long rel_addr, unsigned long rel_size,
107 int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
108 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab))
116 /* Parse the relocation information. */
117 rpnt = (ELF_RELOC *)rel_addr;
118 rel_size /= sizeof(ELF_RELOC);
120 symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
121 strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
123 for (i = 0; i < rel_size; i++, rpnt++) {
126 symtab_index = ELF_R_SYM(rpnt->r_info);
128 debug_sym(symtab, strtab, symtab_index);
129 debug_reloc(symtab, strtab, rpnt);
131 res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
136 _dl_dprintf(2, "\n%s: ", _dl_progname);
139 _dl_dprintf(2, "symbol '%s': ",
140 strtab + symtab[symtab_index].st_name);
142 if (unlikely(res < 0)) {
143 int reloc_type = ELF_R_TYPE(rpnt->r_info);
145 _dl_dprintf(2, "can't handle reloc type "
146 #if defined (__SUPPORT_LD_DEBUG__)
147 "%s\n", _dl_reltypes(reloc_type));
152 } else if (unlikely(res > 0)) {
153 _dl_dprintf(2, "can't resolve symbol\n");
162 _dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
163 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
169 ElfW(Addr) *reloc_addr;
170 ElfW(Addr) symbol_addr;
171 #if defined (__SUPPORT_LD_DEBUG__)
175 reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
176 reloc_type = ELF_R_TYPE(rpnt->r_info);
177 symtab_index = ELF_R_SYM(rpnt->r_info);
178 sym = &symtab[symtab_index];
180 symname = strtab + sym->st_name;
183 symbol_addr = (ElfW(Addr))_dl_find_hash(symname, scope, tpnt,
184 elf_machine_type_class(reloc_type));
186 * We want to allow undefined references to weak symbols - this
187 * might have been intentional. We should not be linking local
188 * symbols here, so all bases should be covered.
190 if (unlikely(!symbol_addr && ELF_ST_BIND(sym->st_info) != STB_WEAK)) {
191 _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
196 #if defined (__SUPPORT_LD_DEBUG__)
197 old_val = *reloc_addr;
200 switch (reloc_type) {
204 *(char *) reloc_addr = symbol_addr + rpnt->r_addend;
207 *(short *) reloc_addr = symbol_addr + rpnt->r_addend;
210 *reloc_addr = symbol_addr + rpnt->r_addend;
213 *(char *) reloc_addr = (symbol_addr + rpnt->r_addend
214 - (unsigned int) reloc_addr);
217 *(short *) reloc_addr = (symbol_addr + rpnt->r_addend
218 - (unsigned int) reloc_addr);
221 *reloc_addr = (symbol_addr + rpnt->r_addend
222 - (unsigned int) reloc_addr);
226 *reloc_addr = symbol_addr;
229 *reloc_addr = ((unsigned int) tpnt->loadaddr
230 /* Compatibility kludge. */
231 + (rpnt->r_addend ? : *reloc_addr));
234 _dl_memcpy ((void *) reloc_addr,
235 (void *) symbol_addr,
236 symtab[symtab_index].st_size);
240 return -1; /* Calls _dl_exit(1). */
243 #if defined (__SUPPORT_LD_DEBUG__)
244 if (_dl_debug_reloc && _dl_debug_detail)
245 _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
246 old_val, *reloc_addr, reloc_addr);
254 _dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
255 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
259 ElfW(Addr) *reloc_addr;
260 #if defined (__SUPPORT_LD_DEBUG__)
265 symtab_index = ELF_R_SYM(rpnt->r_info);
268 reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + rpnt->r_offset);
269 reloc_type = ELF_R_TYPE(rpnt->r_info);
271 #if defined (__SUPPORT_LD_DEBUG__)
272 old_val = *reloc_addr;
275 switch (reloc_type) {
279 *reloc_addr += (unsigned int) tpnt->loadaddr;
285 #if defined (__SUPPORT_LD_DEBUG__)
286 if (_dl_debug_reloc && _dl_debug_detail)
287 _dl_dprintf(_dl_debug_file, "\tpatched_lazy: %x ==> %x @ %x\n",
288 old_val, *reloc_addr, reloc_addr);
296 _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
297 unsigned long rel_addr,
298 unsigned long rel_size)
300 _dl_parse_relocation_information(rpnt, rel_addr, rel_size);
302 (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
307 _dl_parse_relocation_information(struct dyn_elf *rpnt,
308 unsigned long rel_addr,
309 unsigned long rel_size)
311 return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size, _dl_do_reloc);