Elf32_Shdr *elf_section_by_name(Elf32_Ehdr *hdr, char *name) {
int i;
for(i=0; i < hdr->e_shnum; i++) {
if(!strcmp(elf_lookup_sh_string(hdr, elf_section(hdr, i)->sh_name), name))
return elf_section(hdr, i);
}
return NULL;
}
int kmodule_bind_got_reldyn(Elf32_Ehdr *h, t_elfparse *ep, t_elfparse_symb *ksym)
{
int sz;
t_elfparse_sections *secs;
secs = &ep->sections;
sz = secs->reldyn->sh_size / secs->reldyn->sh_entsize - 1;
for ( ; sz >= 0 ; --sz)
{
Elf32_Rel *rel = (Elf32_Rel *)((int)h + secs->reldyn->sh_offset) + sz;
Elf32_Shdr *tab = elf_section(h, secs->reldyn->sh_link);
Elf32_Sym *newsymbol = ((Elf32_Sym *)((int)h + tab->sh_offset)) + ELF32_R_SYM(rel->r_info);
/* printf("%x %x %x\n", rel, tab, newsymbol); */
if (ELF32_R_TYPE(rel->r_info) != R_386_GLOB_DAT)
continue;
if (newsymbol->st_shndx == SHN_UNDEF)
{
Elf32_Sym *newrealsymbol = ((Elf32_Sym *)((int)h + secs->dynsym->sh_offset)) + ELF32_R_SYM(rel->r_info);
char *name = (char *)h + secs->dynstr->sh_addr + newrealsymbol->st_name;
*(unsigned*)((int)h + rel->r_offset) = kresolve_symb(name, ksym);
}
else
*(unsigned*)((int)h + rel->r_offset) = newsymbol->st_value + (int)h;
}
return (0);
}
int kmodule_bind_got_relplt(Elf32_Ehdr *h, t_elfparse *ep, t_elfparse_symb *ksym)
{
int sz;
t_elfparse_sections *secs;
secs = &ep->sections;
sz = secs->relplt->sh_size / secs->relplt->sh_entsize - 1;
for ( ; sz >= 0 ; --sz)
{
Elf32_Rel *rel = (Elf32_Rel *)((int)h + secs->relplt->sh_offset) + sz;
if (ELF32_R_SYM(rel->r_info) == SHN_UNDEF)
{
printf("Skipping undef symb\n");
continue;
}
Elf32_Shdr *tab = elf_section(h, secs->relplt->sh_link);
Elf32_Sym *newsymbol = ((Elf32_Sym *)((int)h + tab->sh_offset)) + ELF32_R_SYM(rel->r_info);
if (newsymbol->st_shndx == SHN_UNDEF)
{
Elf32_Sym *newrealsymbol = ((Elf32_Sym *)((int)h + secs->dynsym->sh_offset)) + ELF32_R_SYM(rel->r_info);
char *name = (char *)h + secs->dynstr->sh_addr + newrealsymbol->st_name;
*(unsigned*)((int)h + rel->r_offset) = kresolve_symb(name, ksym);
}
else
*(unsigned*)((int)h + rel->r_offset) = newsymbol->st_value + (int)h;
}
return (0);
}
int lua_elf_t_section_exists (lua_State * L)
{
struct _elf * elf;
struct _elf_section section;
int section_i;
int found;
char * name;
elf = lua_check_elf(L, 1);
name = (char *) luaL_checkstring(L, 2);
lua_pop(L, 2);
found = 0;
for (section_i = 0; section_i < int_t_get(elf_shnum(elf)); section_i++) {
elf_section(elf, §ion, section_i);
if (strcmp(elf_section_name(§ion), name) == 0) {
found = 1;
break;
}
}
if (found)
lua_pushboolean(L, 1);
else
lua_pushboolean(L, 0);
return 1;
}
int lua_elf_t_symbols (lua_State * L)
{
struct lua_elf_t * elf_t;
struct lua_elf_section_t * section_t;
struct _elf_section section;
struct _elf * elf;
int section_i;
int sym_i;
int symbols_i = 1;
struct lua_elf_symbol_t * symbol_t;
elf_t = lua_check_elf_t(L, 1);
lua_pop(L, 1);
elf = elf_t->elf;
lua_newtable(L);
for (section_i = 0; section_i < int_t_get(elf_shnum(elf)); section_i++) {
elf_section(elf, §ion, section_i);
if ( (int_t_get(elf_section_type(§ion)) == SHT_SYMTAB)
|| (int_t_get(elf_section_type(§ion)) == SHT_DYNSYM)) {
lua_push_elf_section_t(L);
section_t = lua_check_elf_section_t(L, -1);
lua_pop(L, 1);
elf_section(elf, &(section_t->section), section_i);
section_t->elf_t = elf_t;
elf_t->ref_count++;
for (sym_i = 0; sym_i < elf_section_num(§ion); sym_i++) {
lua_pushinteger(L, (lua_Integer) symbols_i++);
lua_push_elf_symbol_t(L);
symbol_t = lua_check_elf_symbol_t(L, -1);
elf_section_symbol(§ion, &(symbol_t->symbol), sym_i);
symbol_t->section_t = section_t;
section_t->ref_count++;
elf_t->ref_count++;
lua_settable(L, -3);
}
}
}
return 1;
}
int lua_elf_t_section (lua_State * L)
{
struct lua_elf_t * elf;
struct _elf_section section;
int section_i = -1;
int found;
struct lua_elf_section_t * section_t;
elf = lua_check_elf_t(L, 1);
if (lua_isnumber(L, 2))
section_i = luaL_checkinteger(L, 2);
else if (lua_isstring(L, 2)) {
found = 0;
for (section_i = 0; section_i < int_t_get(elf_shnum(elf->elf));
section_i++) {
elf_section(elf->elf, §ion, section_i);
if (strcmp(elf_section_name(§ion), lua_tostring(L, 2)) == 0) {
found = 1;
break;
}
}
if (! found)
luaL_error(L, "no section found by name %s", lua_tostring(L, 2));
}
else
luaL_error(L, "expected a string or number");
lua_pop(L, 2);
if (section_i >= int_t_get(elf_shnum(elf->elf)))
luaL_error(L, "elf does not have %d sections", section_i);
lua_push_elf_section_t(L);
section_t = lua_check_elf_section_t(L, 1);
elf_section(elf->elf, &(section_t->section), section_i);
section_t->elf_t = elf;
elf->ref_count++;
return 1;
}
int lua_elf_symbol_t_disassemble (lua_State * L)
{
struct lua_elf_symbol_t * symbol_t;
struct _elf * elf;
struct _elf_symbol symbol;
struct _elf_section section;
unsigned char * data;
int section_i;
int symbol_i;
uint_t offset;
int end_address_set = 0;
uint_t end_address;
uint_t_8_set(&end_address, 0);
symbol_t = lua_check_elf_symbol_t(L, 1);
lua_pop(L, 1);
elf = symbol_t->section_t->elf_t->elf;
// find function sym at next highest address, save it's start address in
// end_address
for (section_i = 0; section_i < int_t_get(elf_shnum(elf)); section_i++) {
elf_section(elf, §ion, section_i);
if (int_t_get(elf_section_type(§ion)) == SHT_SYMTAB) {
for (symbol_i = 0; symbol_i < elf_section_num(§ion); symbol_i++) {
elf_section_symbol(§ion, &symbol, symbol_i);
if ( (elf_symbol_type(&symbol) == STT_FUNC)
&& (uint_t_cmp(elf_symbol_value(&(symbol_t->symbol)),
elf_symbol_value(&symbol)) < 0)
&& (uint_t_cmp(elf_symbol_shndx(&symbol),
elf_symbol_shndx(&(symbol_t->symbol)))
== 0)
&& ( (uint_t_cmp(elf_symbol_value(&symbol),
&end_address) < 0)
|| (end_address_set == 0)
)
) {
uint_t_set(&end_address, elf_symbol_value(&symbol));
end_address_set = 1;
}
}
}
}
// end address not set? set it to the end of the linked section
if (end_address_set == 0) {
elf_section(elf, §ion,
uint_t_get(elf_symbol_shndx(&(symbol_t->symbol))));
uint_t_int_t(&end_address, elf_section_size(§ion));
uint_t_add(&end_address, elf_section_addr(§ion));
}
// load the linked section
elf_section(elf, §ion, uint_t_get(elf_symbol_shndx(&(symbol_t->symbol))));
data = elf_section_data(§ion);
uint_t_set(&offset, elf_symbol_value(&(symbol_t->symbol)));
uint_t_sub(&offset, elf_section_addr(§ion));
// disassemble that function like it was 1980
lua_dis_table(L,
elf_symbol_value(&(symbol_t->symbol)),
&(data[uint_t_get(&offset)]),
uint_t_get(&end_address)
- uint_t_get(elf_symbol_value(&(symbol_t->symbol))),
ELF_CLASS(elf));
return 1;
}
static inline char *elf_str_table(Elf32_Ehdr *hdr) {
if(hdr->e_shstrndx == SHN_UNDEF) return NULL;
return (char *)hdr + elf_section(hdr, hdr->e_shstrndx)->sh_offset;
}
