1 /* vi: set sw=4 ts=4: */
2 /* sparc ELF shared library loader suppport
4 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
5 * David Engel, Hongjiu Lu and Mitch D'Souza
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. The name of the above contributors may not be
15 * used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 /* Program to load an ELF binary on a linux system, and run it.
32 References to symbols in sharable libraries can be resolved by either
33 an ELF sharable library or a linux style of shared library. */
35 /* Disclaimer: I have never seen any AT&T source code for SVr4, nor have
36 I ever taken any courses on internals. This program was developed using
37 information available through the book "UNIX SYSTEM V RELEASE 4,
38 Programmers guide: Ansi C and Programming Support Tools", which did
39 a more than adequate job of explaining everything required to get this
42 /* Some SPARC opcodes we need to use for self-modifying code. */
43 #define OPCODE_NOP 0x01000000 /* nop */
44 #define OPCODE_CALL 0x40000000 /* call ?; add PC-rel word address */
45 #define OPCODE_SETHI_G1 0x03000000 /* sethi ?, %g1; add value>>10 */
46 #define OPCODE_JMP_G1 0x81c06000 /* jmp %g1+?; add lo 10 bits of value */
47 #define OPCODE_SAVE_SP 0x9de3bfa8 /* save %sp, -(16+6)*4, %sp */
48 #define OPCODE_BA 0x30800000 /* b,a ?; add PC-rel word address */
50 extern int _dl_linux_resolve(void);
53 _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
55 ELF_RELOC *this_reloc;
62 ElfW(Addr) instr_addr;
65 rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
67 * Generate the correct relocation index into the .rela.plt section.
69 reloc_entry = (reloc_entry >> 10) - 0xc;
71 this_reloc = (ELF_RELOC *)(rel_addr + reloc_entry);
72 symtab_index = ELF_R_SYM(this_reloc->r_info);
74 symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
75 strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
76 symname = strtab + symtab[symtab_index].st_name;
78 /* Address of the jump instruction to fix up. */
79 instr_addr = (this_reloc->r_offset + tpnt->loadaddr);
80 got_addr = (char **)instr_addr;
82 /* Get the address of the GOT entry */
83 new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
84 if (unlikely(!new_addr)) {
85 _dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname);
89 #if defined (__SUPPORT_LD_DEBUG__)
90 if ((unsigned long)got_addr < 0x40000000) {
91 if (_dl_debug_bindings) {
92 _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
94 _dl_dprintf(_dl_debug_file,
95 "\tpatched: %x ==> %x @ %x\n",
96 *got_addr, new_addr, got_addr);
99 if (!_dl_debug_nofixups)
102 got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
103 got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
106 return (unsigned long)new_addr;
110 _dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
111 unsigned long rel_addr, unsigned long rel_size,
112 int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
113 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab))
121 /* Parse the relocation information. */
122 rpnt = (ELF_RELOC *)rel_addr;
123 rel_size /= sizeof(ELF_RELOC);
125 symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
126 strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
128 for (i = 0; i < rel_size; i++, rpnt++) {
131 symtab_index = ELF_R_SYM(rpnt->r_info);
133 debug_sym(symtab, strtab, symtab_index);
134 debug_reloc(symtab, strtab, rpnt);
136 res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
141 _dl_dprintf(2, "\n%s: ", _dl_progname);
144 _dl_dprintf(2, "symbol '%s': ",
145 strtab + symtab[symtab_index].st_name);
147 if (unlikely(res < 0)) {
148 int reloc_type = ELF_R_TYPE(rpnt->r_info);
150 _dl_dprintf(2, "can't handle reloc type "
151 #if defined (__SUPPORT_LD_DEBUG__)
152 "%s\n", _dl_reltypes(reloc_type));
157 } else if (unlikely(res > 0)) {
158 _dl_dprintf(2, "can't resolve symbol\n");
167 _dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
168 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
174 ElfW(Addr) *reloc_addr;
175 ElfW(Addr) symbol_addr;
176 #if defined (__SUPPORT_LD_DEBUG__)
180 reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
181 reloc_type = ELF_R_TYPE(rpnt->r_info);
182 symtab_index = ELF_R_SYM(rpnt->r_info);
183 sym = &symtab[symtab_index];
185 symname = strtab + sym->st_name;
188 symbol_addr = (ElfW(Addr))_dl_find_hash(symname, scope, tpnt,
189 elf_machine_type_class(reloc_type));
191 * We want to allow undefined references to weak symbols - this
192 * might have been intentional. We should not be linking local
193 * symbols here, so all bases should be covered.
195 if (unlikely(!symbol_addr && ELF_ST_BIND(sym->st_info) != STB_WEAK)) {
196 _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
201 #if defined (__SUPPORT_LD_DEBUG__)
202 old_val = *reloc_addr;
205 symbol_addr += rpnt->r_addend; /* Assume copy relocs have zero addend. */
207 switch (reloc_type) {
211 #if 0 /* these dont really seem to be useful */
213 *(char *) reloc_addr = symbol_addr;
216 *(short *) reloc_addr = symbol_addr;
219 *(char *) reloc_addr = (symbol_addr) - (Elf32_Addr) reloc_addr;
222 *(short *) reloc_addr = (symbol_addr) - (Elf32_Addr) reloc_addr;
227 *reloc_addr = symbol_addr - (unsigned int) reloc_addr;
232 symbol_addr = tpnt->loadaddr + rpnt->r_addend;
234 symbol_addr += rpnt->r_addend;
235 *reloc_addr = (*reloc_addr & ~0x3ff)|(symbol_addr & 0x3ff);
238 case R_SPARC_GLOB_DAT:
240 *reloc_addr = symbol_addr;
243 case R_SPARC_JMP_SLOT:
246 value += reloc->r_addend;
247 disp = value - reloc_addr;
248 reloc_addr[1] = OPCODE_JMP_G1 | (value & 0x3ff);
249 reloc_addr[0] = OPCODE_SETHI_G1 | (value >> 10);
250 reloc_addr[1] = OPCODE_JMP_G1 | ((symbol_addr-(Elf32_Addr)reloc_addr) & 0x3ff);
251 reloc_addr[0] = OPCODE_SETHI_G1 | ((symbol_addr-(Elf32_Addr)reloc_addr) >> 10);
253 reloc_addr[1] = 0x03000000 | ((symbol_addr >> 10) & 0x3fffff);
254 reloc_addr[2] = 0x81c06000 | (symbol_addr & 0x3ff);
257 case R_SPARC_RELATIVE:
258 *reloc_addr += tpnt->loadaddr + rpnt->r_addend;
261 case R_SPARC_WDISP30:
262 *reloc_addr = (*reloc_addr & 0xc0000000)|
263 ((symbol_addr - (unsigned int) reloc_addr) >> 2);
268 symbol_addr = tpnt->loadaddr + rpnt->r_addend;
270 symbol_addr += rpnt->r_addend;
271 *reloc_addr = (*reloc_addr & 0xffc00000) | (symbol_addr >> 10);
276 #if defined (__SUPPORT_LD_DEBUG__)
278 _dl_dprintf(_dl_debug_file,
279 "\t%s move %d bytes from %x to %x\n",
280 symname, sym->st_size,
281 symbol_addr, reloc_addr);
284 _dl_memcpy((char *)reloc_addr,
288 _dl_dprintf(_dl_debug_file, "no symbol_addr to copy !?\n");
291 return -1; /* Calls _dl_exit(1). */
294 #if defined (__SUPPORT_LD_DEBUG__)
295 if (_dl_debug_reloc && _dl_debug_detail)
296 _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
297 old_val, *reloc_addr, reloc_addr);
303 #undef __SPARC_LAZY_RELOC_WORKS
304 #ifdef __SPARC_LAZY_RELOC_WORKS
306 _dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
307 ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
311 ElfW(Addr) *reloc_addr;
312 #if defined (__SUPPORT_LD_DEBUG__)
317 symtab_index = ELF_R_SYM(rpnt->r_info);
320 reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + rpnt->r_offset);
321 reloc_type = ELF_R_TYPE(rpnt->r_info);
323 #if defined (__SUPPORT_LD_DEBUG__)
324 old_val = *reloc_addr;
327 switch (reloc_type) {
330 case R_SPARC_JMP_SLOT:
336 #if defined (__SUPPORT_LD_DEBUG__)
337 if (_dl_debug_reloc && _dl_debug_detail)
338 _dl_dprintf(_dl_debug_file, "\tpatched_lazy: %x ==> %x @ %x\n",
339 old_val, *reloc_addr, reloc_addr);
347 _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
348 unsigned long rel_addr,
349 unsigned long rel_size)
351 #ifdef __SPARC_LAZY_RELOC_WORKS
352 (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
354 _dl_parse_relocation_information(rpnt, rel_addr, rel_size);
359 _dl_parse_relocation_information(struct dyn_elf *rpnt,
360 unsigned long rel_addr,
361 unsigned long rel_size)
363 return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size, _dl_do_reloc);