eresi_Addr elfops_move_ptr(elf_bf_exec_t *e, eresi_Addr delta)
{
elf_bf_link_map_t *l = &(e->ee_lm);
eresi_Addr start = l->lm_next_reloc;
//change tape pointer
set_next_reloc(l, R_X86_64_64, symtab_get_index(e->ee_ptr_tape_ptr),
symtab_get_value_addr(e->ee_ptr_tape_ptr), delta);
//copy new tape value into workspace
set_next_reloc(l, R_X86_64_COPY, symtab_get_index(e->ee_ptr_tape_ptr),
symtab_get_value_addr(e->ee_tape_ptr), 0);
return l->lm_next_reloc - start;
}
eresi_Addr elfops_add(elf_bf_exec_t *ee, eresi_Addr delta)
{
elf_bf_link_map_t *l = &(ee->ee_lm);
eresi_Addr start = l->lm_next_reloc;
//we assume that correct value is in scratch space, just do addition
set_next_reloc(l, R_X86_64_64, symtab_get_index(ee->ee_tape_ptr),
symtab_get_value_addr(ee->ee_tape_ptr), delta);
eresi_Addr setupi, copyi;
elf_bf_Rela setup, copy;
//update tape
setupi = set_next_reloc(l, 0, 0, 0, 0);
//copy new value back to tape
copyi = set_next_reloc(l, R_X86_64_COPY, symtab_get_index(ee->ee_tape_copy),
0, 0);
//go back at actually setup first entry
reloc_get_reloc_entry(l, setupi, &setup);
reloc_get_reloc_entry(l, copyi, ©);
//setup next entry so it knows where tape pointer is
reloc_set_rela(&setup, R_X86_64_64, symtab_get_index(ee->ee_ptr_tape_ptr),
reloc_get_offset_addr(©), 0);
return l->lm_next_reloc - start;
}
eresi_Addr init_scatch_space(elf_bf_exec_t *ee)
{
elf_bf_link_map_t *l = &(ee->ee_lm);
eresi_Addr start = l->lm_next_reloc;
//copy new tape value into workspace
set_next_reloc(l, R_X86_64_COPY, symtab_get_index(ee->ee_ptr_tape_ptr),
symtab_get_value_addr(ee->ee_tape_ptr), 0);
return l->lm_next_reloc - start;
}
//just cont number of symbols if lm_allocated is false
void init_tape_syms(elf_bf_exec_t *env)
{
elf_bf_Sym *sym, *psym, *ifunc, *execmap, *ptrtapecpy, *stackaddr, *getchar, *putchar, *ldbase, *libcbase, *execmapvalue, *putcharextra;
elf_bf_Sym top;
if (env->ee_lm.lm_allocated){
psym = calloc(1, sizeof(elf_bf_Sym));
sym = calloc(1, sizeof(elf_bf_Sym));
ptrtapecpy = calloc(1, sizeof(elf_bf_Sym));
ifunc = calloc(1, sizeof(elf_bf_Sym));
execmap = calloc(1, sizeof(elf_bf_Sym));
stackaddr = calloc(1, sizeof(elf_bf_Sym));
ldbase = calloc(1, sizeof(elf_bf_Sym));
libcbase = calloc(1, sizeof(elf_bf_Sym));
getchar = calloc(1, sizeof(elf_bf_Sym));
putchar = calloc(1, sizeof(elf_bf_Sym));
putcharextra = calloc(1, sizeof(elf_bf_Sym));
execmapvalue = calloc(1, sizeof(elf_bf_Sym));
}
eresi_Addr index = env->ee_num_used_syms;
//index++;
//printf("index: %d\n", index);
//symtab_get_sym(&(env->ee_lm), index++, nsym);
symtab_get_sym(&(env->ee_lm), index++, psym);
symtab_get_sym(&(env->ee_lm), index++, sym);
symtab_get_sym(&(env->ee_lm), index++, ifunc);
symtab_get_sym(&(env->ee_lm), index++, ptrtapecpy);
symtab_get_sym(&(env->ee_lm), index++, execmap);
symtab_get_sym(&(env->ee_lm), index++, stackaddr);
symtab_get_sym(&(env->ee_lm), index++, ldbase);
symtab_get_sym(&(env->ee_lm), index++, libcbase);
symtab_get_sym(&(env->ee_lm), index++, getchar);
symtab_get_sym(&(env->ee_lm), index++, putchar);
symtab_get_sym(&(env->ee_lm), index++, putcharextra);
symtab_get_sym(&(env->ee_lm), index, execmapvalue);
if (env->ee_lm.lm_allocated){
env->ee_num_used_syms = index;
symtab_get_sym(&(env->ee_lm), index+1, &top);
//keeps the tape head symbol number
//address of where tape head is pointing's value
symtab_set_sym(psym, 1, top.addr, STT_FUNC);
//assume tape head value is zero
symtab_set_sym(sym, 1, 0, STT_FUNC);
symtab_set_sym(ifunc, 8, 0, STT_GNU_IFUNC);
//elfsh_set_symbol_link(ifunc->sym, 1);
symtab_set_sym(ptrtapecpy, 1, symtab_get_value_addr(sym), STT_FUNC);
//start it up with address of PLTGOT
elfsh_Dyn *dyn;
eresi_Addr pltgot;
dyn = elfsh_get_dynamic_entry_by_type(env->ee_lm.lm_f, DT_PLTGOT);
pltgot = elfsh_get_dynentry_val(dyn);
env->ee_dt_pltgot = pltgot+8;
symtab_set_sym(execmap, 8, pltgot+8, STT_FUNC);
symtab_set_sym(stackaddr, 8, 0, STT_FUNC);
symtab_set_sym(ldbase, 8, 0, STT_FUNC);
symtab_set_sym(libcbase, 8, 0, STT_FUNC);
symtab_set_sym(getchar, 8, 0, STT_FUNC);
symtab_set_sym(putchar, 8, 0, STT_FUNC);
symtab_set_sym(putcharextra, 0, 0, STT_FUNC); //we jsut want a readable address here
//printf("ptr_tape_ptr %x, tape_ptr %x, copy %x\n", symtab_get_index(psym), symtab_get_index(sym), symtab_get_index(ptrtapecpy));
symtab_set_sym(execmapvalue, 8, 0, STT_FUNC);
//env->ee_tape_symnum = psym->index;
env->ee_ptr_tape_ptr = psym;
env->ee_tape_ptr = sym;
env->ee_lm.lm_ifunc = ifunc;
env->ee_ptr_tape_copy = ptrtapecpy;
env->ee_exec_map = execmap;
env->ee_stack_addr = stackaddr;
env->ee_ld_base = ldbase;
env->ee_libc_base = libcbase;
env->ee_lm.lm_getchar = getchar;
env->ee_lm.lm_putchar = putchar;
env->ee_lm.lm_putcharextra = putcharextra;
env->ee_exec_map_value = execmapvalue;
}
env->ee_num_new_syms = index - env->ee_num_used_syms;
}
