574 lines
17 KiB
Python
574 lines
17 KiB
Python
#!/usr/bin/env python3
|
|
#
|
|
# Copyright (c) 2017-2018 Linaro
|
|
#
|
|
# SPDX-License-Identifier: Apache-2.0
|
|
|
|
import sys
|
|
import os
|
|
import struct
|
|
from distutils.version import LooseVersion
|
|
|
|
from collections import OrderedDict
|
|
|
|
import elftools
|
|
from elftools.elf.elffile import ELFFile
|
|
from elftools.elf.sections import SymbolTableSection
|
|
|
|
if LooseVersion(elftools.__version__) < LooseVersion('0.24'):
|
|
sys.stderr.write("pyelftools is out of date, need version 0.24 or later\n")
|
|
sys.exit(1)
|
|
|
|
|
|
def subsystem_to_enum(subsys):
|
|
return "K_OBJ_DRIVER_" + subsys[:-11].upper()
|
|
|
|
|
|
def kobject_to_enum(kobj):
|
|
if kobj.startswith("k_") or kobj.startswith("_k_"):
|
|
name = kobj[2:]
|
|
else:
|
|
name = kobj
|
|
|
|
return "K_OBJ_%s" % name.upper()
|
|
|
|
|
|
DW_OP_addr = 0x3
|
|
DW_OP_fbreg = 0x91
|
|
STACK_TYPE = "_k_thread_stack_element"
|
|
thread_counter = 0
|
|
sys_mutex_counter = 0
|
|
futex_counter = 0
|
|
|
|
# Global type environment. Populated by pass 1.
|
|
type_env = {}
|
|
extern_env = {}
|
|
kobjects = {}
|
|
subsystems = {}
|
|
|
|
# --- debug stuff ---
|
|
|
|
scr = os.path.basename(sys.argv[0])
|
|
|
|
# --- type classes ----
|
|
|
|
|
|
class KobjectInstance:
|
|
def __init__(self, type_obj, addr):
|
|
global thread_counter
|
|
global sys_mutex_counter
|
|
global futex_counter
|
|
|
|
self.addr = addr
|
|
self.type_obj = type_obj
|
|
|
|
# Type name determined later since drivers needs to look at the
|
|
# API struct address
|
|
self.type_name = None
|
|
|
|
if self.type_obj.name == "k_thread":
|
|
# Assign an ID for this thread object, used to track its
|
|
# permissions to other kernel objects
|
|
self.data = thread_counter
|
|
thread_counter = thread_counter + 1
|
|
elif self.type_obj.name == "sys_mutex":
|
|
self.data = "(u32_t)(&kernel_mutexes[%d])" % sys_mutex_counter
|
|
sys_mutex_counter += 1
|
|
elif self.type_obj.name == "k_futex":
|
|
self.data = "(u32_t)(&futex_data[%d])" % futex_counter
|
|
futex_counter += 1
|
|
else:
|
|
self.data = 0
|
|
|
|
|
|
class KobjectType:
|
|
def __init__(self, offset, name, size, api=False):
|
|
self.name = name
|
|
self.size = size
|
|
self.offset = offset
|
|
self.api = api
|
|
|
|
def __repr__(self):
|
|
return "<kobject %s>" % self.name
|
|
|
|
def has_kobject(self):
|
|
return True
|
|
|
|
def get_kobjects(self, addr):
|
|
return {addr: KobjectInstance(self, addr)}
|
|
|
|
|
|
class ArrayType:
|
|
def __init__(self, offset, elements, member_type):
|
|
self.elements = elements
|
|
self.member_type = member_type
|
|
self.offset = offset
|
|
|
|
def __repr__(self):
|
|
return "<array of %d>" % self.member_type
|
|
|
|
def has_kobject(self):
|
|
if self.member_type not in type_env:
|
|
return False
|
|
|
|
return type_env[self.member_type].has_kobject()
|
|
|
|
def get_kobjects(self, addr):
|
|
mt = type_env[self.member_type]
|
|
|
|
# Stacks are arrays of _k_stack_element_t but we want to treat
|
|
# the whole array as one kernel object (a thread stack)
|
|
# Data value gets set to size of entire region
|
|
if isinstance(mt, KobjectType) and mt.name == STACK_TYPE:
|
|
# An array of stacks appears as a multi-dimensional array.
|
|
# The last size is the size of each stack. We need to track
|
|
# each stack within the array, not as one huge stack object.
|
|
*dimensions, stacksize = self.elements
|
|
num_members = 1
|
|
for e in dimensions:
|
|
num_members = num_members * e
|
|
|
|
ret = {}
|
|
for i in range(num_members):
|
|
a = addr + (i * stacksize)
|
|
o = mt.get_kobjects(a)
|
|
o[a].data = stacksize
|
|
ret.update(o)
|
|
return ret
|
|
|
|
objs = {}
|
|
|
|
# Multidimensional array flattened out
|
|
num_members = 1
|
|
for e in self.elements:
|
|
num_members = num_members * e
|
|
|
|
for i in range(num_members):
|
|
objs.update(mt.get_kobjects(addr + (i * mt.size)))
|
|
return objs
|
|
|
|
|
|
class AggregateTypeMember:
|
|
def __init__(self, offset, member_name, member_type, member_offset):
|
|
self.member_name = member_name
|
|
self.member_type = member_type
|
|
if isinstance(member_offset, list):
|
|
# DWARF v2, location encoded as set of operations
|
|
# only "DW_OP_plus_uconst" with ULEB128 argument supported
|
|
if member_offset[0] == 0x23:
|
|
self.member_offset = member_offset[1] & 0x7f
|
|
for i in range(1, len(member_offset)-1):
|
|
if member_offset[i] & 0x80:
|
|
self.member_offset += (
|
|
member_offset[i+1] & 0x7f) << i*7
|
|
else:
|
|
raise Exception("not yet supported location operation (%s:%d:%d)" %
|
|
(self.member_name, self.member_type, member_offset[0]))
|
|
else:
|
|
self.member_offset = member_offset
|
|
|
|
def __repr__(self):
|
|
return "<member %s, type %d, offset %d>" % (
|
|
self.member_name, self.member_type, self.member_offset)
|
|
|
|
def has_kobject(self):
|
|
if self.member_type not in type_env:
|
|
return False
|
|
|
|
return type_env[self.member_type].has_kobject()
|
|
|
|
def get_kobjects(self, addr):
|
|
mt = type_env[self.member_type]
|
|
return mt.get_kobjects(addr + self.member_offset)
|
|
|
|
|
|
class ConstType:
|
|
def __init__(self, child_type):
|
|
self.child_type = child_type
|
|
|
|
def __repr__(self):
|
|
return "<const %d>" % self.child_type
|
|
|
|
def has_kobject(self):
|
|
if self.child_type not in type_env:
|
|
return False
|
|
|
|
return type_env[self.child_type].has_kobject()
|
|
|
|
def get_kobjects(self, addr):
|
|
return type_env[self.child_type].get_kobjects(addr)
|
|
|
|
|
|
class AggregateType:
|
|
def __init__(self, offset, name, size):
|
|
self.name = name
|
|
self.size = size
|
|
self.offset = offset
|
|
self.members = []
|
|
|
|
def add_member(self, member):
|
|
self.members.append(member)
|
|
|
|
def __repr__(self):
|
|
return "<struct %s, with %s>" % (self.name, self.members)
|
|
|
|
def has_kobject(self):
|
|
result = False
|
|
|
|
bad_members = []
|
|
|
|
for member in self.members:
|
|
if member.has_kobject():
|
|
result = True
|
|
else:
|
|
bad_members.append(member)
|
|
# Don't need to consider this again, just remove it
|
|
|
|
for bad_member in bad_members:
|
|
self.members.remove(bad_member)
|
|
|
|
return result
|
|
|
|
def get_kobjects(self, addr):
|
|
objs = {}
|
|
for member in self.members:
|
|
objs.update(member.get_kobjects(addr))
|
|
return objs
|
|
|
|
|
|
# --- helper functions for getting data from DIEs ---
|
|
|
|
def die_get_spec(die):
|
|
if 'DW_AT_specification' not in die.attributes:
|
|
return None
|
|
|
|
spec_val = die.attributes["DW_AT_specification"].value
|
|
|
|
# offset of the DW_TAG_variable for the extern declaration
|
|
offset = spec_val + die.cu.cu_offset
|
|
|
|
return extern_env.get(offset)
|
|
|
|
|
|
def die_get_name(die):
|
|
if 'DW_AT_name' not in die.attributes:
|
|
die = die_get_spec(die)
|
|
if not die:
|
|
return None
|
|
|
|
return die.attributes["DW_AT_name"].value.decode("utf-8")
|
|
|
|
|
|
def die_get_type_offset(die):
|
|
if 'DW_AT_type' not in die.attributes:
|
|
die = die_get_spec(die)
|
|
if not die:
|
|
return None
|
|
|
|
return die.attributes["DW_AT_type"].value + die.cu.cu_offset
|
|
|
|
|
|
def die_get_byte_size(die):
|
|
if 'DW_AT_byte_size' not in die.attributes:
|
|
return 0
|
|
|
|
return die.attributes["DW_AT_byte_size"].value
|
|
|
|
|
|
def analyze_die_struct(die):
|
|
name = die_get_name(die) or "<anon>"
|
|
offset = die.offset
|
|
size = die_get_byte_size(die)
|
|
|
|
# Incomplete type
|
|
if not size:
|
|
return
|
|
|
|
if name in kobjects:
|
|
type_env[offset] = KobjectType(offset, name, size)
|
|
elif name in subsystems:
|
|
type_env[offset] = KobjectType(offset, name, size, api=True)
|
|
else:
|
|
at = AggregateType(offset, name, size)
|
|
type_env[offset] = at
|
|
|
|
for child in die.iter_children():
|
|
if child.tag != "DW_TAG_member":
|
|
continue
|
|
child_type = die_get_type_offset(child)
|
|
member_offset = \
|
|
child.attributes["DW_AT_data_member_location"].value
|
|
cname = die_get_name(child) or "<anon>"
|
|
m = AggregateTypeMember(child.offset, cname, child_type,
|
|
member_offset)
|
|
at.add_member(m)
|
|
|
|
return
|
|
|
|
|
|
def analyze_die_const(die):
|
|
type_offset = die_get_type_offset(die)
|
|
if not type_offset:
|
|
return
|
|
|
|
type_env[die.offset] = ConstType(type_offset)
|
|
|
|
|
|
def analyze_die_array(die):
|
|
type_offset = die_get_type_offset(die)
|
|
elements = []
|
|
|
|
for child in die.iter_children():
|
|
if child.tag != "DW_TAG_subrange_type":
|
|
continue
|
|
if "DW_AT_upper_bound" not in child.attributes:
|
|
continue
|
|
|
|
ub = child.attributes["DW_AT_upper_bound"]
|
|
if not ub.form.startswith("DW_FORM_data"):
|
|
continue
|
|
|
|
elements.append(ub.value + 1)
|
|
|
|
if not elements:
|
|
return
|
|
|
|
type_env[die.offset] = ArrayType(die.offset, elements, type_offset)
|
|
|
|
|
|
def addr_deref(elf, addr):
|
|
for section in elf.iter_sections():
|
|
start = section['sh_addr']
|
|
end = start + section['sh_size']
|
|
|
|
if addr >= start and addr < end:
|
|
data = section.data()
|
|
offset = addr - start
|
|
return struct.unpack("<I" if elf.little_endian else ">I",
|
|
data[offset:offset + 4])[0]
|
|
|
|
return 0
|
|
|
|
|
|
def device_get_api_addr(elf, addr):
|
|
return addr_deref(elf, addr + 4)
|
|
|
|
|
|
def get_filename_lineno(die):
|
|
lp_header = die.dwarfinfo.line_program_for_CU(die.cu).header
|
|
files = lp_header["file_entry"]
|
|
includes = lp_header["include_directory"]
|
|
|
|
fileinfo = files[die.attributes["DW_AT_decl_file"].value - 1]
|
|
filename = fileinfo.name.decode("utf-8")
|
|
filedir = includes[fileinfo.dir_index - 1].decode("utf-8")
|
|
|
|
path = os.path.join(filedir, filename)
|
|
lineno = die.attributes["DW_AT_decl_line"].value
|
|
return (path, lineno)
|
|
|
|
|
|
class ElfHelper:
|
|
|
|
def __init__(self, filename, verbose, kobjs, subs):
|
|
self.verbose = verbose
|
|
self.fp = open(filename, "rb")
|
|
self.elf = ELFFile(self.fp)
|
|
self.little_endian = self.elf.little_endian
|
|
global kobjects
|
|
global subsystems
|
|
kobjects = kobjs
|
|
subsystems = subs
|
|
|
|
def find_kobjects(self, syms):
|
|
if not self.elf.has_dwarf_info():
|
|
sys.stderr.write("ELF file has no DWARF information\n")
|
|
sys.exit(1)
|
|
|
|
app_smem_start = syms["_app_smem_start"]
|
|
app_smem_end = syms["_app_smem_end"]
|
|
|
|
di = self.elf.get_dwarf_info()
|
|
|
|
variables = []
|
|
|
|
# Step 1: collect all type information.
|
|
for CU in di.iter_CUs():
|
|
for die in CU.iter_DIEs():
|
|
# Unions are disregarded, kernel objects should never be union
|
|
# members since the memory is not dedicated to that object and
|
|
# could be something else
|
|
if die.tag == "DW_TAG_structure_type":
|
|
analyze_die_struct(die)
|
|
elif die.tag == "DW_TAG_const_type":
|
|
analyze_die_const(die)
|
|
elif die.tag == "DW_TAG_array_type":
|
|
analyze_die_array(die)
|
|
elif die.tag == "DW_TAG_variable":
|
|
variables.append(die)
|
|
|
|
# Step 2: filter type_env to only contain kernel objects, or structs
|
|
# and arrays of kernel objects
|
|
bad_offsets = []
|
|
for offset, type_object in type_env.items():
|
|
if not type_object.has_kobject():
|
|
bad_offsets.append(offset)
|
|
|
|
for offset in bad_offsets:
|
|
del type_env[offset]
|
|
|
|
# Step 3: Now that we know all the types we are looking for, examine
|
|
# all variables
|
|
all_objs = {}
|
|
|
|
for die in variables:
|
|
name = die_get_name(die)
|
|
if not name:
|
|
continue
|
|
|
|
if name.startswith("__device_sys_init"):
|
|
# Boot-time initialization function; not an actual device
|
|
continue
|
|
|
|
type_offset = die_get_type_offset(die)
|
|
|
|
# Is this a kernel object, or a structure containing kernel
|
|
# objects?
|
|
if type_offset not in type_env:
|
|
continue
|
|
|
|
if "DW_AT_declaration" in die.attributes:
|
|
# Extern declaration, only used indirectly
|
|
extern_env[die.offset] = die
|
|
continue
|
|
|
|
if "DW_AT_location" not in die.attributes:
|
|
self.debug_die(
|
|
die,
|
|
"No location information for object '%s'; possibly"
|
|
" stack allocated" % name)
|
|
continue
|
|
|
|
loc = die.attributes["DW_AT_location"]
|
|
if loc.form != "DW_FORM_exprloc" and \
|
|
loc.form != "DW_FORM_block1":
|
|
self.debug_die(
|
|
die,
|
|
"kernel object '%s' unexpected location format" %
|
|
name)
|
|
continue
|
|
|
|
opcode = loc.value[0]
|
|
if opcode != DW_OP_addr:
|
|
|
|
# Check if frame pointer offset DW_OP_fbreg
|
|
if opcode == DW_OP_fbreg:
|
|
self.debug_die(die, "kernel object '%s' found on stack" %
|
|
name)
|
|
else:
|
|
self.debug_die(
|
|
die,
|
|
"kernel object '%s' unexpected exprloc opcode %s" %
|
|
(name, hex(opcode)))
|
|
continue
|
|
|
|
addr = (loc.value[1] | (loc.value[2] << 8) |
|
|
(loc.value[3] << 16) | (loc.value[4] << 24))
|
|
|
|
if addr == 0:
|
|
# Never linked; gc-sections deleted it
|
|
continue
|
|
|
|
type_obj = type_env[type_offset]
|
|
objs = type_obj.get_kobjects(addr)
|
|
all_objs.update(objs)
|
|
|
|
self.debug("symbol '%s' at %s contains %d object(s)"
|
|
% (name, hex(addr), len(objs)))
|
|
|
|
# Step 4: objs is a dictionary mapping variable memory addresses to
|
|
# their associated type objects. Now that we have seen all variables
|
|
# and can properly look up API structs, convert this into a dictionary
|
|
# mapping variables to the C enumeration of what kernel object type it
|
|
# is.
|
|
ret = {}
|
|
for addr, ko in all_objs.items():
|
|
# API structs don't get into the gperf table
|
|
if ko.type_obj.api:
|
|
continue
|
|
|
|
_, user_ram_allowed = kobjects[ko.type_obj.name]
|
|
if (not user_ram_allowed and
|
|
(addr >= app_smem_start and addr < app_smem_end)):
|
|
|
|
self.debug_die(die,
|
|
"object '%s' found in invalid location %s"
|
|
% (name, hex(addr)))
|
|
continue
|
|
|
|
if ko.type_obj.name != "device":
|
|
# Not a device struct so we immediately know its type
|
|
ko.type_name = kobject_to_enum(ko.type_obj.name)
|
|
ret[addr] = ko
|
|
continue
|
|
|
|
# Device struct. Need to get the address of its API struct,
|
|
# if it has one.
|
|
apiaddr = device_get_api_addr(self.elf, addr)
|
|
if apiaddr not in all_objs:
|
|
if apiaddr == 0:
|
|
self.debug("device instance at 0x%x has no associated subsystem"
|
|
% addr)
|
|
else:
|
|
self.debug("device instance at 0x%x has unknown API 0x%x"
|
|
% (addr, apiaddr))
|
|
# API struct does not correspond to a known subsystem, skip it
|
|
continue
|
|
|
|
apiobj = all_objs[apiaddr]
|
|
ko.type_name = subsystem_to_enum(apiobj.type_obj.name)
|
|
ret[addr] = ko
|
|
|
|
self.debug("found %d kernel object instances total" % len(ret))
|
|
|
|
# 1. Before python 3.7 dict order is not guaranteed. With Python
|
|
# 3.5 it doesn't seem random with *integer* keys but can't
|
|
# rely on that.
|
|
# 2. OrderedDict means _insertion_ order, so not enough because
|
|
# built from other (random!) dicts: need to _sort_ first.
|
|
# 3. Sorting memory address looks good.
|
|
return OrderedDict(sorted(ret.items()))
|
|
|
|
def get_symbols(self):
|
|
for section in self.elf.iter_sections():
|
|
if isinstance(section, SymbolTableSection):
|
|
return {sym.name: sym.entry.st_value
|
|
for sym in section.iter_symbols()}
|
|
|
|
raise LookupError("Could not find symbol table")
|
|
|
|
def debug(self, text):
|
|
if not self.verbose:
|
|
return
|
|
sys.stdout.write(scr + ": " + text + "\n")
|
|
|
|
def error(self, text):
|
|
sys.stderr.write("%s ERROR: %s\n" % (scr, text))
|
|
sys.exit(1)
|
|
|
|
def debug_die(self, die, text):
|
|
fn, ln = get_filename_lineno(die)
|
|
|
|
self.debug(str(die))
|
|
self.debug("File '%s', line %d:" % (fn, ln))
|
|
self.debug(" %s" % text)
|
|
|
|
def get_thread_counter(self):
|
|
return thread_counter
|
|
|
|
def get_sys_mutex_counter(self):
|
|
return sys_mutex_counter
|
|
|
|
def get_futex_counter(self):
|
|
return futex_counter
|