123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355 |
- /* Run an ELF binary on a linux system.
- Copyright (C) 1995, 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. */
- #ifndef VERBOSE_DLINKER
- #define VERBOSE_DLINKER
- #endif
- #ifdef VERBOSE_DLINKER
- static char * _dl_reltypes[] = { "R_SPARC_NONE", "R_SPARC_8",
- "R_SPARC_16", "R_SPARC_32", "R_SPARC_DISP8", "R_SPARC_DISP16",
- "R_SPARC_DISP32", "R_SPARC_WDISP30", "R_SPARC_WDISP22",
- "R_SPARC_HI22", "R_SPARC_22", "R_SPARC_13", "R_SPARC_LO10",
- "R_SPARC_GOT10", "R_SPARC_GOT13", "R_SPARC_GOT22", "R_SPARC_PC10",
- "R_SPARC_PC22", "R_SPARC_WPLT30", "R_SPARC_COPY",
- "R_SPARC_GLOB_DAT", "R_SPARC_JMP_SLOT", "R_SPARC_RELATIVE",
- "R_SPARC_UA32"};
- #endif
- /* 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. */
- #include <linux/types.h>
- #include <linux/errno.h>
- #include <linux/unistd.h>
- /*#include <stdlib.h>*/
- #include "string.h"
- #include <linux/unistd.h>
- #include <linux/fcntl.h>
- #include "hash.h"
- #include "linuxelf.h"
- #include "sysdep.h"
- #include "../syscall.h"
- #include "../string.h"
- #define SVR4_COMPATIBILITY
- extern char *_dl_progname;
- extern _dl_linux_resolve(void);
- unsigned int _dl_linux_resolver(unsigned int reloc_entry, unsigned int * plt)
- {
- int reloc_type;
- struct elf32_rela * this_reloc;
- char * strtab;
- struct elf32_sym * symtab;
- struct elf32_rela * rel_addr;
- struct elf_resolve * tpnt;
- int symtab_index;
- char * new_addr;
- char ** got_addr;
- unsigned int instr_addr;
- tpnt = (struct elf_resolve *) plt[2];
- rel_addr = (struct elf32_rela *) (tpnt->dynamic_info[DT_JMPREL] +
- tpnt->loadaddr);
- /*
- * Generate the correct relocation index into the .rela.plt section.
- */
- reloc_entry = (reloc_entry >> 12) - 0xc;
- this_reloc = (struct elf32_rela *) ((char *) rel_addr + reloc_entry);
- reloc_type = ELF32_R_TYPE(this_reloc->r_info);
- symtab_index = ELF32_R_SYM(this_reloc->r_info);
- symtab = (struct elf32_sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
- _dl_fdprintf(2, "tpnt = %x\n", tpnt);
- _dl_fdprintf(2, "reloc = %x\n", this_reloc);
- _dl_fdprintf(2, "symtab = %x\n", symtab);
- _dl_fdprintf(2, "strtab = %x\n", strtab);
- if (reloc_type != R_SPARC_JMP_SLOT) {
- _dl_fdprintf(2, "%s: incorrect relocation type in jump relocations (%d)\n",
- _dl_progname, reloc_type);
- _dl_exit(30);
- };
- /* Address of jump instruction to fix up */
- instr_addr = ((int)this_reloc->r_offset + (int)tpnt->loadaddr);
- got_addr = (char **) instr_addr;
- _dl_fdprintf(2, "symtab_index %d\n", symtab_index);
- #ifdef DEBUG
- _dl_fdprintf(2, "Resolving symbol %s\n",
- strtab + symtab[symtab_index].st_name);
- #endif
- /* Get the address of the GOT entry */
- new_addr = _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope, (int) got_addr, tpnt, 0);
- if(!new_addr) {
- _dl_fdprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- _dl_exit(31);
- };
- /* #define DEBUG_LIBRARY */
- #ifdef DEBUG_LIBRARY
- if((unsigned int) got_addr < 0x40000000) {
- _dl_fdprintf(2, "Calling library function: %s\n",
- strtab + symtab[symtab_index].st_name);
- } else {
- got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
- got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
- }
- #else
- got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
- got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
- #endif
- _dl_fdprintf(2, "Address = %x\n",new_addr);
- _dl_exit(32);
- return (unsigned int) new_addr;
- }
- void _dl_parse_lazy_relocation_information(struct elf_resolve * tpnt, int rel_addr,
- int rel_size, int type){
- int i;
- char * strtab;
- int reloc_type;
- int symtab_index;
- struct elf32_sym * symtab;
- struct elf32_rela * rpnt;
- unsigned int * reloc_addr;
- /* Now parse the relocation information */
- rpnt = (struct elf32_rela *) (rel_addr + tpnt->loadaddr);
- symtab = (struct elf32_sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = ( char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
- for(i=0; i< rel_size; i += sizeof(struct elf32_rela), rpnt++){
- reloc_addr = (int *) (tpnt->loadaddr + (int)rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- 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))
- continue;
- switch(reloc_type){
- case R_SPARC_NONE:
- break;
- case R_SPARC_JMP_SLOT:
- break;
- default:
- _dl_fdprintf(2, "%s: (LAZY) can't handle reloc type ", _dl_progname);
- #ifdef VERBOSE_DLINKER
- _dl_fdprintf(2, "%s ", _dl_reltypes[reloc_type]);
- #endif
- if(symtab_index) _dl_fdprintf(2, "'%s'\n",
- strtab + symtab[symtab_index].st_name);
- _dl_exit(33);
- };
- };
- }
- int _dl_parse_relocation_information(struct elf_resolve * tpnt, int rel_addr,
- int rel_size, int type){
- int i;
- char * strtab;
- int reloc_type;
- int goof = 0;
- struct elf32_sym * symtab;
- struct elf32_rela * rpnt;
- unsigned int * reloc_addr;
- unsigned int symbol_addr;
- int symtab_index;
- /* Now parse the relocation information */
- rpnt = (struct elf32_rela *) (rel_addr + tpnt->loadaddr);
- symtab = (struct elf32_sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = ( char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
- for(i=0; i< rel_size; i+= sizeof(struct elf32_rela), rpnt++){
- reloc_addr = (int *) (tpnt->loadaddr + (int)rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- 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 int)
- _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope, (int) reloc_addr,
- (reloc_type == R_SPARC_JMP_SLOT ? tpnt : NULL), 0);
- if(!symbol_addr &&
- ELF32_ST_BIND(symtab [symtab_index].st_info) == STB_GLOBAL) {
- _dl_fdprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- goof++;
- };
- };
- switch(reloc_type){
- case R_SPARC_NONE:
- break;
- case R_SPARC_32:
- *reloc_addr = symbol_addr + rpnt->r_addend;
- break;
- case R_SPARC_DISP32:
- *reloc_addr = symbol_addr + rpnt->r_addend - (unsigned int) reloc_addr;
- break;
- case R_SPARC_GLOB_DAT:
- *reloc_addr = symbol_addr + rpnt->r_addend;
- break;
- case R_SPARC_JMP_SLOT:
- reloc_addr[1] = 0x03000000 | ((symbol_addr >> 10) & 0x3fffff);
- reloc_addr[2] = 0x81c06000 | (symbol_addr & 0x3ff);
- break;
- case R_SPARC_RELATIVE:
- *reloc_addr += (unsigned int) tpnt->loadaddr + rpnt->r_addend;
- break;
- case R_SPARC_HI22:
- if (!symbol_addr)
- symbol_addr = tpnt->loadaddr + rpnt->r_addend;
- else
- symbol_addr += rpnt->r_addend;
- *reloc_addr = (*reloc_addr & 0xffc00000)|(symbol_addr >> 10);
- break;
- case R_SPARC_LO10:
- if (!symbol_addr)
- symbol_addr = tpnt->loadaddr + rpnt->r_addend;
- else
- symbol_addr += rpnt->r_addend;
- *reloc_addr = (*reloc_addr & ~0x3ff)|(symbol_addr & 0x3ff);
- break;
- case R_SPARC_WDISP30:
- *reloc_addr = (*reloc_addr & 0xc0000000)|
- ((symbol_addr - (unsigned int) reloc_addr) >> 2);
- break;
- case R_SPARC_COPY:
- #if 0 /* This one is done later */
- _dl_fdprintf(2, "Doing copy for symbol ");
- if(symtab_index) _dl_fdprintf(2, strtab + symtab[symtab_index].st_name);
- _dl_fdprintf(2, "\n");
- _dl_memcpy((void *) symtab[symtab_index].st_value,
- (void *) symbol_addr,
- symtab[symtab_index].st_size);
- #endif
- break;
- default:
- _dl_fdprintf(2, "%s: can't handle reloc type ", _dl_progname);
- #ifdef VERBOSE_DLINKER
- _dl_fdprintf(2, "%s ", _dl_reltypes[reloc_type]);
- #endif
- if (symtab_index)
- _dl_fdprintf(2, "'%s'\n", strtab + symtab[symtab_index].st_name);
- _dl_exit(34);
- };
- };
- return goof;
- }
- /* 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, int rel_addr,
- int rel_size, int type)
- {
- int i;
- char * strtab;
- int reloc_type;
- int goof = 0;
- struct elf32_sym * symtab;
- struct elf32_rela * rpnt;
- unsigned int * reloc_addr;
- unsigned int symbol_addr;
- struct elf_resolve *tpnt;
- int symtab_index;
- /* Now parse the relocation information */
- tpnt = xpnt->dyn;
-
- rpnt = (struct elf32_rela *) (rel_addr + tpnt->loadaddr);
- symtab = (struct elf32_sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
- strtab = ( char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
- for(i=0; i< rel_size; i+= sizeof(struct elf32_rela), rpnt++){
- reloc_addr = (int *) (tpnt->loadaddr + (int)rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- if(reloc_type != R_SPARC_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 int)
- _dl_find_hash(strtab + symtab[symtab_index].st_name,
- xpnt->next, (int) reloc_addr, NULL, 1);
- if(!symbol_addr) {
- _dl_fdprintf(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;
- }
|