/* Try to start up libdw on DEBUGFILE. */
static Dwfl_Error
load_dw (Dwfl_Module *mod, struct dwfl_file *debugfile)
{
if (mod->e_type == ET_REL && !debugfile->relocated)
{
const Dwfl_Callbacks *const cb = mod->dwfl->callbacks;
/* The debugging sections have to be relocated. */
if (cb->section_address == NULL)
return DWFL_E_NOREL;
Dwfl_Error error = __libdwfl_module_getebl (mod);
if (error != DWFL_E_NOERROR)
return error;
find_symtab (mod);
Dwfl_Error result = mod->symerr;
if (result == DWFL_E_NOERROR)
result = __libdwfl_relocate (mod, debugfile->elf, true);
if (result != DWFL_E_NOERROR)
return result;
/* Don't keep the file descriptors around. */
if (mod->main.fd != -1 && elf_cntl (mod->main.elf, ELF_C_FDREAD) == 0)
{
close (mod->main.fd);
mod->main.fd = -1;
}
if (debugfile->fd != -1 && elf_cntl (debugfile->elf, ELF_C_FDREAD) == 0)
{
close (debugfile->fd);
debugfile->fd = -1;
}
}
mod->dw = INTUSE(dwarf_begin_elf) (debugfile->elf, DWARF_C_READ, NULL);
if (mod->dw == NULL)
{
int err = INTUSE(dwarf_errno) ();
return err == DWARF_E_NO_DWARF ? DWFL_E_NO_DWARF : DWFL_E (LIBDW, err);
}
/* Until we have iterated through all CU's, we might do lazy lookups. */
mod->lazycu = 1;
return DWFL_E_NOERROR;
}
internal_function
__libdwfl_set_cfi (Dwfl_Module *mod, Dwarf_CFI **slot, Dwarf_CFI *cfi)
{
if (cfi != NULL && cfi->ebl == NULL)
{
Dwfl_Error error = __libdwfl_module_getebl (mod);
if (error == DWFL_E_NOERROR)
cfi->ebl = mod->ebl;
else
{
if (slot == &mod->eh_cfi)
INTUSE(dwarf_cfi_end) (cfi);
__libdwfl_seterrno (error);
return NULL;
}
}
return *slot = cfi;
}
Elf *
dwfl_module_getelf (Dwfl_Module *mod, GElf_Addr *loadbase)
{
if (mod == NULL)
return NULL;
find_file (mod);
if (mod->elferr == DWFL_E_NOERROR)
{
if (mod->e_type == ET_REL && ! mod->main.relocated)
{
/* Before letting them get at the Elf handle,
apply all the relocations we know how to. */
mod->main.relocated = true;
if (likely (__libdwfl_module_getebl (mod) == DWFL_E_NOERROR))
{
(void) __libdwfl_relocate (mod, mod->main.elf, false);
if (mod->debug.elf == mod->main.elf)
mod->debug.relocated = true;
else if (mod->debug.elf != NULL && ! mod->debug.relocated)
{
mod->debug.relocated = true;
(void) __libdwfl_relocate (mod, mod->debug.elf, false);
}
}
}
*loadbase = mod->main.bias;
return mod->main.elf;
}
__libdwfl_seterrno (mod->elferr);
return NULL;
}
internal_function
__libdwfl_getsym (Dwfl_Module *mod, int ndx, GElf_Sym *sym, GElf_Addr *addr,
GElf_Word *shndxp, Elf **elfp, Dwarf_Addr *biasp,
bool *resolved, bool adjust_st_value)
{
if (unlikely (mod == NULL))
return NULL;
if (unlikely (mod->symdata == NULL))
{
int result = INTUSE(dwfl_module_getsymtab) (mod);
if (result < 0)
return NULL;
}
/* All local symbols should come before all global symbols. If we
have an auxiliary table make sure all the main locals come first,
then all aux locals, then all main globals and finally all aux globals.
And skip the auxiliary table zero undefined entry. */
GElf_Word shndx;
int tndx = ndx;
int skip_aux_zero = (mod->syments > 0 && mod->aux_syments > 0) ? 1 : 0;
Elf *elf;
Elf_Data *symdata;
Elf_Data *symxndxdata;
Elf_Data *symstrdata;
if (mod->aux_symdata == NULL
|| ndx < mod->first_global)
{
/* main symbol table (locals). */
tndx = ndx;
elf = mod->symfile->elf;
symdata = mod->symdata;
symxndxdata = mod->symxndxdata;
symstrdata = mod->symstrdata;
}
else if (ndx < mod->first_global + mod->aux_first_global - skip_aux_zero)
{
/* aux symbol table (locals). */
tndx = ndx - mod->first_global + skip_aux_zero;
elf = mod->aux_sym.elf;
symdata = mod->aux_symdata;
symxndxdata = mod->aux_symxndxdata;
symstrdata = mod->aux_symstrdata;
}
else if ((size_t) ndx < mod->syments + mod->aux_first_global - skip_aux_zero)
{
/* main symbol table (globals). */
tndx = ndx - mod->aux_first_global + skip_aux_zero;
elf = mod->symfile->elf;
symdata = mod->symdata;
symxndxdata = mod->symxndxdata;
symstrdata = mod->symstrdata;
}
else
{
/* aux symbol table (globals). */
tndx = ndx - mod->syments + skip_aux_zero;
elf = mod->aux_sym.elf;
symdata = mod->aux_symdata;
symxndxdata = mod->aux_symxndxdata;
symstrdata = mod->aux_symstrdata;
}
sym = gelf_getsymshndx (symdata, symxndxdata, tndx, sym, &shndx);
if (unlikely (sym == NULL))
{
__libdwfl_seterrno (DWFL_E_LIBELF);
return NULL;
}
if (sym->st_shndx != SHN_XINDEX)
shndx = sym->st_shndx;
/* Figure out whether this symbol points into an SHF_ALLOC section. */
bool alloc = true;
if ((shndxp != NULL || mod->e_type != ET_REL)
&& (sym->st_shndx == SHN_XINDEX
|| (sym->st_shndx < SHN_LORESERVE && sym->st_shndx != SHN_UNDEF)))
{
GElf_Shdr shdr_mem;
GElf_Shdr *shdr = gelf_getshdr (elf_getscn (elf, shndx), &shdr_mem);
alloc = unlikely (shdr == NULL) || (shdr->sh_flags & SHF_ALLOC);
}
/* In case of an value in an allocated section the main Elf Ebl
might know where the real value is (e.g. for function
descriptors). */
char *ident;
GElf_Addr st_value = sym->st_value & ebl_func_addr_mask (mod->ebl);
*resolved = false;
if (! adjust_st_value && mod->e_type != ET_REL && alloc
&& (GELF_ST_TYPE (sym->st_info) == STT_FUNC
|| (GELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC
&& (ident = elf_getident (elf, NULL)) != NULL
&& ident[EI_OSABI] == ELFOSABI_LINUX)))
{
if (likely (__libdwfl_module_getebl (mod) == DWFL_E_NOERROR))
{
if (elf != mod->main.elf)
{
st_value = dwfl_adjusted_st_value (mod, elf, st_value);
st_value = dwfl_deadjust_st_value (mod, mod->main.elf, st_value);
}
*resolved = ebl_resolve_sym_value (mod->ebl, &st_value);
if (! *resolved)
st_value = sym->st_value;
}
}
if (shndxp != NULL)
/* Yield -1 in case of a non-SHF_ALLOC section. */
*shndxp = alloc ? shndx : (GElf_Word) -1;
switch (sym->st_shndx)
{
case SHN_ABS: /* XXX sometimes should use bias?? */
case SHN_UNDEF:
case SHN_COMMON:
break;
default:
if (mod->e_type == ET_REL)
{
/* In an ET_REL file, the symbol table values are relative
to the section, not to the module's load base. */
size_t symshstrndx = SHN_UNDEF;
Dwfl_Error result = __libdwfl_relocate_value (mod, elf,
&symshstrndx,
shndx, &st_value);
if (unlikely (result != DWFL_E_NOERROR))
{
__libdwfl_seterrno (result);
return NULL;
}
}
else if (alloc)
/* Apply the bias to the symbol value. */
st_value = dwfl_adjusted_st_value (mod,
*resolved ? mod->main.elf : elf,
st_value);
break;
}
if (adjust_st_value)
sym->st_value = st_value;
if (addr != NULL)
*addr = st_value;
if (unlikely (sym->st_name >= symstrdata->d_size))
{
__libdwfl_seterrno (DWFL_E_BADSTROFF);
return NULL;
}
if (elfp)
*elfp = elf;
if (biasp)
*biasp = dwfl_adjusted_st_value (mod, elf, 0);
return (const char *) symstrdata->d_buf + sym->st_name;
}
