--- /dev/null
+/* vi: set sw=4 ts=4: */
+/* x86_64 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
+ an ELF sharable library or a linux style of shared library. */
+
+/* Disclaimer: I have never seen any AT&T source code for SVr4, nor have
+ I ever taken any courses on internals. This program was developed using
+ information available through the book "UNIX SYSTEM V RELEASE 4,
+ Programmers guide: Ansi C and Programming Support Tools", which did
+ a more than adequate job of explaining everything required to get this
+ working. */
+
+extern int _dl_linux_resolve(void);
+
+unsigned long
+_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
+{
+ int reloc_type;
+ ELF_RELOC *this_reloc;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ int symtab_index;
+ char *rel_addr;
+ char *new_addr;
+ char **got_addr;
+ ElfW(Addr) instr_addr;
+ char *symname;
+
+ rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
+ this_reloc = (ELF_RELOC *)(rel_addr + reloc_entry);
+ reloc_type = ELF_R_TYPE(this_reloc->r_info);
+ symtab_index = ELF_R_SYM(this_reloc->r_info);
+
+ symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+ symname = strtab + symtab[symtab_index].st_name;
+
+ if (unlikely(reloc_type != R_X86_64_JUMP_SLOT)) {
+ _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
+ _dl_progname);
+ _dl_exit(1);
+ }
+
+ /* Address of the jump instruction to fix up. */
+ instr_addr = (this_reloc->r_offset + tpnt->loadaddr);
+ got_addr = (char **)instr_addr;
+
+ /* 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'\n", _dl_progname, symname);
+ _dl_exit(1);
+ }
+
+#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,
+ "\tpatched: %x ==> %x @ %x\n",
+ *got_addr, new_addr, got_addr);
+ }
+ }
+ if (!_dl_debug_nofixups)
+#endif
+ *got_addr = new_addr;
+
+ return (unsigned long)new_addr;
+}
+
+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, ElfW(Sym) *symtab, char *strtab))
+{
+ unsigned int i;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ ELF_RELOC *rpnt;
+ int symtab_index;
+
+ /* Parse the relocation information. */
+ rpnt = (ELF_RELOC *)rel_addr;
+ rel_size /= sizeof(ELF_RELOC);
+
+ symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+
+ for (i = 0; i < rel_size; i++, rpnt++) {
+ int res;
+
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+
+ debug_sym(symtab, strtab, symtab_index);
+ debug_reloc(symtab, strtab, rpnt);
+
+ res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
+
+ if (res == 0)
+ continue;
+
+ _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 = ELF_R_TYPE(rpnt->r_info);
+
+ _dl_dprintf(2, "can't handle reloc type "
+#if defined (__SUPPORT_LD_DEBUG__)
+ "%s\n", _dl_reltypes(reloc_type));
+#else
+ "%x\n", reloc_type);
+#endif
+ _dl_exit(-res);
+ } else if (unlikely(res > 0)) {
+ _dl_dprintf(2, "can't resolve symbol\n");
+ return res;
+ }
+ }
+
+ return 0;
+}
+
+static int
+_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
+{
+ int reloc_type;
+ int symtab_index;
+ char *symname;
+ ElfW(Addr) *reloc_addr;
+ ElfW(Addr) symbol_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+ ElfW(Addr) old_val;
+#endif
+
+ reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+ symbol_addr = 0;
+ symname = strtab + symtab[symtab_index].st_name;
+
+ if (symtab_index) {
+ symbol_addr = (ElfW(Addr))_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 && ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) {
+ _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
+ _dl_exit(1);
+ };
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ old_val = *reloc_addr;
+#endif
+
+ switch (reloc_type) {
+ case R_X86_64_NONE:
+ break;
+
+ case R_X86_64_64:
+ *reloc_addr = symbol_addr + rpnt->r_addend;
+ break;
+
+ case R_X86_64_PC32:
+ *reloc_addr = symbol_addr + rpnt->r_addend - rpnt->r_offset;
+ break;
+
+ case R_X86_64_GLOB_DAT:
+ case R_X86_64_JUMP_SLOT:
+ *reloc_addr = symbol_addr;
+ break;
+
+ /* handled by elf_machine_relative()
+ case R_X86_64_RELATIVE:
+ *reloc_addr = map->l_addr + rpnt->r_addend;
+ break;
+ */
+#if 0
+ case R_X86_64_DTPMOD64:
+ break;
+ case R_X86_64_DTPOFF64:
+ *reloc_addr = symbol_addr + rpnt->r_addend;
+ break;
+ case R_X86_64_TPOFF64:
+ *reloc_addr = symbol_addr + rpnt->r_addend;
+ break;
+ case R_X86_64_32:
+ *reloc_addr = symbol_addr + rpnt->r_addend;
+ break;
+
+#endif
+ case R_X86_64_COPY:
+ if (symbol_addr) {
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_move)
+ _dl_dprintf(_dl_debug_file,
+ "\t%s move %d bytes from %x to %x\n",
+ symname, symtab[symtab_index].st_size,
+ symbol_addr, reloc_addr);
+#endif
+
+ _dl_memcpy((char *)reloc_addr,
+ (char *)symbol_addr,
+ symtab[symtab_index].st_size);
+ } else
+ _dl_dprintf(_dl_debug_file, "no symbol_addr to copy !?\n");
+ break;
+
+ default:
+ return -1; /* Calls _dl_exit(1). */
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
+ old_val, *reloc_addr, reloc_addr);
+#endif
+
+ return 0;
+}
+
+#if 0
+static int
+_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
+{
+ int reloc_type;
+ int symtab_index;
+ ElfW(Addr) *reloc_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+ ElfW(Addr) old_val;
+#endif
+
+ (void)scope;
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+ (void)strtab;
+
+ reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ old_val = *reloc_addr;
+#endif
+
+ switch (reloc_type) {
+ case R_X86_64_NONE:
+ break;
+ case R_X86_64_JUMP_SLOT:
+ *reloc_addr = tpnt->loadaddr + symtab[symtab_index].st_value;
+ break;
+ default:
+ _dl_exit(1);
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\tpatched_lazy: %x ==> %x @ %x\n",
+ old_val, *reloc_addr, reloc_addr);
+#endif
+
+ return 0;
+}
+#endif
+
+void
+_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ _dl_parse_relocation_information(rpnt, rel_addr, rel_size);
+/* jump slot isnt working
+ (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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