def get_kconfig(prog: Program) -> Mapping[str, str]:
"""
Get the kernel build configuration as a mapping from the option name to the
value.
>>> get_kconfig(prog)['CONFIG_SMP']
'y'
>>> get_kconfig(prog)['CONFIG_HZ']
'300'
This is only supported if the kernel was compiled with ``CONFIG_IKCONFIG``.
Note that most Linux distributions do not enable this option.
"""
try:
return prog.cache["kconfig_map"]
except KeyError:
pass
try:
start = prog.symbol("kernel_config_data").address
size = prog.symbol("kernel_config_data_end").address - start
except LookupError:
# Before Linux kernel commit 13610aa908dc ("kernel/configs: use .incbin
# directive to embed config_data.gz") (in v5.1), the data is a variable
# rather than two symbols.
try:
kernel_config_data = prog["kernel_config_data"]
except KeyError:
raise LookupError(
"kernel configuration data not found; kernel must be compiled with CONFIG_IKCONFIG"
)
# The data is delimited by the magic strings "IKCFG_ST" and "IKCFG_ED"
# plus a NUL byte.
start = kernel_config_data.address_ + 8 # type: ignore[operator]
size = len(kernel_config_data) - 17
data = prog.read(start, size)
kconfig = {}
for line in gzip.decompress(data).decode().splitlines():
if not line or line.startswith("#"):
continue
name, _, value = line.partition("=")
if value:
kconfig[name] = value
# Make result mapping 'immutable', so changes cannot propagate to the cache
result = types.MappingProxyType(kconfig)
prog.cache["kconfig_map"] = result
return result
def _test_module_debug_info(self, use_proc_and_sys):
old_use_proc_and_sys = (
int(os.environ.get("DRGN_USE_PROC_AND_SYS_MODULES", "1")) != 0
)
with setenv("DRGN_USE_PROC_AND_SYS_MODULES", "1" if use_proc_and_sys else "0"):
if old_use_proc_and_sys == use_proc_and_sys:
prog = self.prog
else:
prog = Program()
prog.set_kernel()
self._load_debug_info(prog)
self.assertEqual(prog.symbol(self.SYMBOL).address, self.symbol_address)
