/* We have an authoritative build ID for this module MOD, so don't use
a file by name that doesn't match that ID. */
static void
mod_verify_build_id (Dwfl_Module *mod)
{
assert (mod->build_id_len > 0);
switch (__builtin_expect (__libdwfl_find_build_id (mod, false,
mod->main.elf), 2))
{
case 2:
/* Build ID matches as it should. */
return;
case -1: /* ELF error. */
mod->elferr = INTUSE(dwfl_errno) ();
break;
case 0: /* File has no build ID note. */
case 1: /* FIle has a build ID that does not match. */
mod->elferr = DWFL_E_WRONG_ID_ELF;
break;
default:
abort ();
}
/* We get here when it was the right ELF file. Clear it out. */
elf_end (mod->main.elf);
mod->main.elf = NULL;
if (mod->main.fd >= 0)
{
close (mod->main.fd);
mod->main.fd = -1;
}
}
int
dwfl_module_build_id (Dwfl_Module *mod,
const unsigned char **bits, GElf_Addr *vaddr)
{
if (mod == NULL)
return -1;
if (mod->build_id_len == 0 && mod->main.elf != NULL)
{
/* We have the file, but have not examined it yet. */
int result = __libdwfl_find_build_id (mod, true, mod->main.elf);
if (result <= 0)
{
mod->build_id_len = -1; /* Cache negative result. */
return result;
}
}
if (mod->build_id_len <= 0)
return 0;
*bits = mod->build_id_bits;
*vaddr = mod->build_id_vaddr;
return mod->build_id_len;
}
static bool
validate (Dwfl_Module *mod, int fd, bool check, GElf_Word debuglink_crc)
{
/* For alt debug files always check the build-id from the Dwarf and alt. */
if (mod->dw != NULL)
{
bool valid = false;
const void *build_id;
const char *altname;
ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw,
&altname,
&build_id);
if (build_id_len > 0)
{
/* We need to open an Elf handle on the file so we can check its
build ID note for validation. Backdoor the handle into the
module data structure since we had to open it early anyway. */
Dwfl_Error error = __libdw_open_file (&fd, &mod->alt_elf,
false, false);
if (error != DWFL_E_NOERROR)
__libdwfl_seterrno (error);
else
{
const void *alt_build_id;
ssize_t alt_len = INTUSE(dwelf_elf_gnu_build_id) (mod->alt_elf,
&alt_build_id);
if (alt_len > 0 && alt_len == build_id_len
&& memcmp (build_id, alt_build_id, alt_len) == 0)
valid = true;
else
{
/* A mismatch! */
elf_end (mod->alt_elf);
mod->alt_elf = NULL;
close (fd);
fd = -1;
}
}
}
return valid;
}
/* If we have a build ID, check only that. */
if (mod->build_id_len > 0)
{
/* We need to open an Elf handle on the file so we can check its
build ID note for validation. Backdoor the handle into the
module data structure since we had to open it early anyway. */
mod->debug.valid = false;
Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, false, false);
if (error != DWFL_E_NOERROR)
__libdwfl_seterrno (error);
else if (likely (__libdwfl_find_build_id (mod, false,
mod->debug.elf) == 2))
/* Also backdoor the gratuitous flag. */
mod->debug.valid = true;
else
{
/* A mismatch! */
elf_end (mod->debug.elf);
mod->debug.elf = NULL;
close (fd);
fd = -1;
}
return mod->debug.valid;
}
return !check || check_crc (fd, debuglink_crc);
}
