-/* Run an ELF binary on a linux system.
-
- Copyright (C) 1993, Eric Youngdale.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
-\f
-#ifndef VERBOSE_DLINKER
-#define VERBOSE_DLINKER
-#endif
-#ifdef VERBOSE_DLINKER
-static char *_dl_reltypes[] =
- { "R_386_NONE", "R_386_32", "R_386_PC32", "R_386_GOT32",
- "R_386_PLT32", "R_386_COPY", "R_386_GLOB_DAT",
- "R_386_JMP_SLOT", "R_386_RELATIVE", "R_386_GOTOFF",
- "R_386_GOTPC", "R_386_NUM"
-};
-#endif
+/* vi: set sw=4 ts=4: */
+/* i386 ELF shared library loader suppport
+ *
+ * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
+ * David Engel, Hongjiu Lu and Mitch D'Souza
+ * Copyright (C) 2001-2004 Erik Andersen
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. The name of the above contributors may not be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "ldso.h"
/* Program to load an ELF binary on a linux system, and run it.
References to symbols in sharable libraries can be resolved by either
extern int _dl_linux_resolve(void);
-unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
+unsigned long
+_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
{
int reloc_type;
- Elf32_Rel *this_reloc;
+ ELF_RELOC *this_reloc;
char *strtab;
Elf32_Sym *symtab;
- Elf32_Rel *rel_addr;
int symtab_index;
+ char *rel_addr;
char *new_addr;
char **got_addr;
unsigned long instr_addr;
+ char *symname;
- rel_addr = (Elf32_Rel *) (tpnt->dynamic_info[DT_JMPREL] + tpnt->loadaddr);
-
- this_reloc = rel_addr + (reloc_entry >> 3);
+ rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
+ this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry);
reloc_type = ELF32_R_TYPE(this_reloc->r_info);
symtab_index = ELF32_R_SYM(this_reloc->r_info);
- symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
+ symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+ symname = strtab + symtab[symtab_index].st_name;
-
- if (reloc_type != R_386_JMP_SLOT) {
- _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
- _dl_progname);
+ if (unlikely(reloc_type != R_386_JMP_SLOT)) {
+ _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
+ _dl_progname);
_dl_exit(1);
- };
-
- /* Address of jump instruction to fix up */
- instr_addr = ((unsigned long) this_reloc->r_offset +
- (unsigned long) tpnt->loadaddr);
- got_addr = (char **) instr_addr;
+ }
-#ifdef DL_DEBUG_SYMBOLS
- _dl_dprintf(2, "Resolving symbol %s\n",
- strtab + symtab[symtab_index].st_name);
-#endif
+ /* Address of the jump instruction to fix up. */
+ instr_addr = ((unsigned long)this_reloc->r_offset +
+ (unsigned long)tpnt->loadaddr);
+ got_addr = (char **)instr_addr;
- /* Get the address of the GOT entry */
- new_addr = _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope, tpnt, 0);
- if (!new_addr) {
- _dl_dprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
+ /* Get the address of the GOT entry. */
+ new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
+ if (unlikely(!new_addr)) {
+ _dl_dprintf(2, "%s: can't resolve symbol '%s' in lib '%s'.\n", _dl_progname, symname, tpnt->libname);
_dl_exit(1);
- };
-#ifdef DL_NEVER_FIXUP_SYMBOLS
- if ((unsigned long) got_addr < 0x40000000) {
- _dl_dprintf(2, "Calling library function: %s\n",
- strtab + symtab[symtab_index].st_name);
- } else {
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if ((unsigned long)got_addr < 0x40000000) {
+ if (_dl_debug_bindings) {
+ _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
+ if (_dl_debug_detail)
+ _dl_dprintf(_dl_debug_file,
+ "\n\tpatched: %x ==> %x @ %x",
+ *got_addr, new_addr, got_addr);
+ }
+ }
+ if (!_dl_debug_nofixups) {
*got_addr = new_addr;
}
#else
*got_addr = new_addr;
#endif
- return (unsigned long) new_addr;
+
+ return (unsigned long)new_addr;
}
-void _dl_parse_lazy_relocation_information(struct elf_resolve *tpnt,
- unsigned long rel_addr, unsigned long rel_size, int type)
+static int
+_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ unsigned long rel_addr, unsigned long rel_size,
+ int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab))
{
- int i;
+ unsigned int i;
char *strtab;
- int reloc_type;
- int symtab_index;
Elf32_Sym *symtab;
- Elf32_Rel *rpnt;
- unsigned long *reloc_addr;
+ ELF_RELOC *rpnt;
+ int symtab_index;
- /* Now parse the relocation information */
- rpnt = (Elf32_Rel *) (rel_addr + tpnt->loadaddr);
- rel_size = rel_size / sizeof(Elf32_Rel);
+ /* Parse the relocation information. */
+ rpnt = (ELF_RELOC *)(intptr_t)rel_addr;
+ rel_size /= sizeof(ELF_RELOC);
- symtab =
- (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
+ symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
for (i = 0; i < rel_size; i++, rpnt++) {
- reloc_addr = (unsigned long *) (tpnt->loadaddr + (unsigned long) rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
+ int res;
+
symtab_index = ELF32_R_SYM(rpnt->r_info);
- /* When the dynamic linker bootstrapped itself, it resolved some symbols.
- Make sure we do not do them again */
- if (!symtab_index && tpnt->libtype == program_interpreter)
- continue;
- if (symtab_index && tpnt->libtype == program_interpreter &&
- _dl_symbol(strtab + symtab[symtab_index].st_name))
+ debug_sym(symtab, strtab, symtab_index);
+ debug_reloc(symtab, strtab, rpnt);
+
+ res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
+
+ if (res == 0)
continue;
- switch (reloc_type) {
- case R_386_NONE:
- break;
- case R_386_JMP_SLOT:
- *reloc_addr += (unsigned long) tpnt->loadaddr;
- break;
- default:
- _dl_dprintf(2, "%s: (LAZY) can't handle reloc type ",
- _dl_progname);
-#ifdef VERBOSE_DLINKER
- _dl_dprintf(2, "%s ", _dl_reltypes[reloc_type]);
+ _dl_dprintf(2, "\n%s: ", _dl_progname);
+
+ if (symtab_index)
+ _dl_dprintf(2, "symbol '%s': ",
+ strtab + symtab[symtab_index].st_name);
+
+ if (unlikely(res < 0)) {
+ int reloc_type = ELF32_R_TYPE(rpnt->r_info);
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ _dl_dprintf(2, "can't handle reloc type '%s' in lib '%s'\n",
+ _dl_reltypes(reloc_type), tpnt->libname);
+#else
+ _dl_dprintf(2, "can't handle reloc type %x in lib '%s'\n",
+ reloc_type, tpnt->libname);
#endif
- if (symtab_index)
- _dl_dprintf(2, "'%s'\n", strtab + symtab[symtab_index].st_name);
- _dl_exit(1);
- };
- };
+ return res;
+ } else if (unlikely(res > 0)) {
+ _dl_dprintf(2, "can't resolve symbol in lib '%s'.\n", tpnt->libname);
+ return res;
+ }
+ }
+
+ return 0;
}
-int _dl_parse_relocation_information(struct elf_resolve *tpnt,
- unsigned long rel_addr, unsigned long rel_size, int type)
+static int
+_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
- int i;
- char *strtab;
int reloc_type;
- int goof = 0;
- Elf32_Sym *symtab;
- Elf32_Rel *rpnt;
+ int symtab_index;
+ char *symname;
unsigned long *reloc_addr;
unsigned long symbol_addr;
- int symtab_index;
-
- /* Now parse the relocation information */
-
- rpnt = (Elf32_Rel *) (rel_addr + tpnt->loadaddr);
- rel_size = rel_size / sizeof(Elf32_Rel);
-
- symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
+#if defined (__SUPPORT_LD_DEBUG__)
+ unsigned long old_val;
+#endif
- for (i = 0; i < rel_size; i++, rpnt++) {
- reloc_addr = (unsigned long *) (tpnt->loadaddr + (unsigned long) rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- symtab_index = ELF32_R_SYM(rpnt->r_info);
- symbol_addr = 0;
+ reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+ reloc_type = ELF32_R_TYPE(rpnt->r_info);
+ symtab_index = ELF32_R_SYM(rpnt->r_info);
+ symbol_addr = 0;
+ symname = strtab + symtab[symtab_index].st_name;
+
+ if (symtab_index) {
+ symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt,
+ elf_machine_type_class(reloc_type));
+
+ /*
+ * We want to allow undefined references to weak symbols - this
+ * might have been intentional. We should not be linking local
+ * symbols here, so all bases should be covered.
+ */
+ if (unlikely(!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK))
+ return 1;
+ }
- if (!symtab_index && tpnt->libtype == program_interpreter)
- continue;
+#if defined (__SUPPORT_LD_DEBUG__)
+ old_val = *reloc_addr;
+#endif
- if (symtab_index) {
-
- if (tpnt->libtype == program_interpreter &&
- _dl_symbol(strtab + symtab[symtab_index].st_name))
- continue;
-
- symbol_addr = (unsigned long) _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope,
- (reloc_type == R_386_JMP_SLOT ? tpnt : NULL), 0);
-
- /*
- * We want to allow undefined references to weak symbols - this might
- * have been intentional. We should not be linking local symbols
- * here, so all bases should be covered.
- */
- if (!symbol_addr &&
- ELF32_ST_BIND(symtab[symtab_index].st_info) == STB_GLOBAL) {
- _dl_dprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- goof++;
- }
- }
- switch (reloc_type) {
+ switch (reloc_type) {
case R_386_NONE:
break;
case R_386_32:
*reloc_addr += symbol_addr;
break;
case R_386_PC32:
- *reloc_addr += symbol_addr - (unsigned long) reloc_addr;
+ *reloc_addr += symbol_addr - (unsigned long)reloc_addr;
break;
case R_386_GLOB_DAT:
case R_386_JMP_SLOT:
*reloc_addr = symbol_addr;
break;
case R_386_RELATIVE:
- *reloc_addr += (unsigned long) tpnt->loadaddr;
+ *reloc_addr += (unsigned long)tpnt->loadaddr;
break;
case R_386_COPY:
-#if 0
- /* Do this later */
- _dl_dprintf(2, "Doing copy for symbol ");
- if (symtab_index) _dl_dprintf(2, strtab + symtab[symtab_index].st_name);
- _dl_dprintf(2, "\n");
- _dl_memcpy((void *) symtab[symtab_index].st_value,
- (void *) symbol_addr, symtab[symtab_index].st_size);
+ if (symbol_addr) {
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_move)
+ _dl_dprintf(_dl_debug_file,
+ "\n%s move %d bytes from %x to %x",
+ symname, symtab[symtab_index].st_size,
+ symbol_addr, reloc_addr);
#endif
+
+ _dl_memcpy((char *)reloc_addr,
+ (char *)symbol_addr,
+ symtab[symtab_index].st_size);
+ }
break;
default:
- _dl_dprintf(2, "%s: can't handle reloc type ", _dl_progname);
-#ifdef VERBOSE_DLINKER
- _dl_dprintf(2, "%s ", _dl_reltypes[reloc_type]);
+ return -1;
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x",
+ old_val, *reloc_addr, reloc_addr);
#endif
- if (symtab_index)
- _dl_dprintf(2, "'%s'\n", strtab + symtab[symtab_index].st_name);
- _dl_exit(1);
- };
- };
- return goof;
+ return 0;
}
-
-/* This is done as a separate step, because there are cases where
- information is first copied and later initialized. This results in
- the wrong information being copied. Someone at Sun was complaining about
- a bug in the handling of _COPY by SVr4, and this may in fact be what he
- was talking about. Sigh. */
-
-/* No, there are cases where the SVr4 linker fails to emit COPY relocs
- at all */
-
-int _dl_parse_copy_information(struct dyn_elf *xpnt, unsigned long rel_addr,
- unsigned long rel_size, int type)
+static int
+_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
- int i;
- char *strtab;
int reloc_type;
- int goof = 0;
- Elf32_Sym *symtab;
- Elf32_Rel *rpnt;
unsigned long *reloc_addr;
- unsigned long symbol_addr;
- struct elf_resolve *tpnt;
- int symtab_index;
+#if defined (__SUPPORT_LD_DEBUG__)
+ unsigned long old_val;
+#endif
- /* Now parse the relocation information */
+ (void)scope;
+ (void)symtab;
+ (void)strtab;
- tpnt = xpnt->dyn;
+ reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+ reloc_type = ELF32_R_TYPE(rpnt->r_info);
- rpnt = (Elf32_Rel *) (rel_addr + tpnt->loadaddr);
- rel_size = rel_size / sizeof(Elf32_Rel);
+#if defined (__SUPPORT_LD_DEBUG__)
+ old_val = *reloc_addr;
+#endif
- symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
+ switch (reloc_type) {
+ case R_386_NONE:
+ break;
+ case R_386_JMP_SLOT:
+ *reloc_addr += (unsigned long)tpnt->loadaddr;
+ break;
+ default:
+ return -1;
+ }
- for (i = 0; i < rel_size; i++, rpnt++) {
- reloc_addr = (unsigned long *) (tpnt->loadaddr + (unsigned long) rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- if (reloc_type != R_386_COPY)
- continue;
- symtab_index = ELF32_R_SYM(rpnt->r_info);
- symbol_addr = 0;
- if (!symtab_index && tpnt->libtype == program_interpreter)
- continue;
- if (symtab_index) {
-
- if (tpnt->libtype == program_interpreter &&
- _dl_symbol(strtab + symtab[symtab_index].st_name))
- continue;
-
- symbol_addr = (unsigned long) _dl_find_hash(strtab +
- symtab[symtab_index].st_name, xpnt->next,
- NULL, 1);
- if (!symbol_addr) {
- _dl_dprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- goof++;
- };
- };
- if (!goof) {
- _dl_memcpy((char *) symtab[symtab_index].st_value,
- (char *) symbol_addr, symtab[symtab_index].st_size);
- }
- };
- return goof;
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x",
+ old_val, *reloc_addr, reloc_addr);
+#endif
+
+ return 0;
+}
+
+void
+_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
+}
+
+int
+_dl_parse_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size, _dl_do_reloc);
}
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