# pylint:disable=abstract-method,arguments-differ
import logging
from typing import Optional, List, Set, Tuple
from angr.utils.dynamic_dictlist import DynamicDictList
from angr.storage.memory_object import SimMemoryObject, SimLabeledMemoryObject
from . import PageBase
from .cooperation import MemoryObjectMixin
l = logging.getLogger(name=__name__)
[docs]class ListPage(MemoryObjectMixin, PageBase):
"""
This class implements a page memory mixin with lists as the main content store.
"""
[docs] def __init__(self, memory=None, content=None, sinkhole=None, mo_cmp=None, **kwargs):
super().__init__(**kwargs)
self.content: Optional[DynamicDictList[Optional[SimMemoryObject]]] = (
DynamicDictList(max_size=memory.page_size, content=content) if content is not None else None
)
self.stored_offset = set()
if self.content is None:
if memory is not None:
self.content: DynamicDictList[Optional[SimMemoryObject]] = DynamicDictList(max_size=memory.page_size)
self._mo_cmp = mo_cmp
self.sinkhole: Optional[SimMemoryObject] = sinkhole
[docs] def copy(self, memo):
o = super().copy(memo)
o.content = DynamicDictList(max_size=self.content.max_size, content=self.content)
o.stored_offset = self.stored_offset.copy()
o.sinkhole = self.sinkhole
o._mo_cmp = self._mo_cmp
return o
[docs] def load(self, addr, size=None, endness=None, page_addr=None, memory=None, cooperate=False, **kwargs):
result = []
last_seen = ... # ;)
# loop over the loading range. accumulate a result for each byte, but collapse results from adjacent bytes
# using the same memory object
for subaddr in range(addr, addr + size):
item = self.content[subaddr]
if item is None:
item = self.sinkhole
if item is not last_seen:
if last_seen is None:
self._fill(result, subaddr, page_addr, endness, memory, **kwargs)
result.append((subaddr + page_addr, item))
last_seen = item
if last_seen is None:
self._fill(result, addr + size, page_addr, endness, memory, **kwargs)
if not cooperate:
result = self._force_load_cooperation(result, size, endness, memory=memory, **kwargs)
return result
def _fill(self, result, addr, page_addr, endness, memory, **kwargs):
"""
Small utility function for behavior which is duplicated in load
mutates result to generate a new memory object and replace the last entry in it, which is None. Then, it will
insert the new memory object into self.content.
"""
global_end_addr = addr + page_addr
global_start_addr = result[-1][0]
size = global_end_addr - global_start_addr
new_ast = self._default_value(
global_start_addr,
size,
name=f"{memory.id}_{global_start_addr:x}",
key=(self.category, global_start_addr),
memory=memory,
**kwargs,
)
new_item = SimMemoryObject(
new_ast,
global_start_addr,
endness=endness,
byte_width=memory.state.arch.byte_width if memory is not None else 8,
)
subaddr_start = global_start_addr - page_addr
for subaddr in range(subaddr_start, addr):
self.content[subaddr] = new_item
self.stored_offset.add(subaddr)
result[-1] = (global_start_addr, new_item)
[docs] def store(self, addr, data, size=None, endness=None, memory=None, cooperate=False, **kwargs):
super().store(addr, data, size=size, endness=endness, memory=memory, cooperate=cooperate, **kwargs)
if not cooperate:
data = self._force_store_cooperation(addr, data, size, endness, memory=memory, **kwargs)
if size == len(self.content) and addr == 0:
self.sinkhole = data
self.content = DynamicDictList(max_size=len(self.content))
else:
max_addr = min(addr + size, len(self.content))
for subaddr in range(addr, max_addr):
self.content[subaddr] = data
self.stored_offset.add(subaddr)
[docs] def erase(self, addr, size=None, **kwargs) -> None:
for off in range(size):
self.content[addr + off] = None
[docs] def merge(
self,
others: List["ListPage"],
merge_conditions,
common_ancestor=None,
page_addr: int = None,
memory=None,
changed_offsets: Optional[Set[int]] = None,
):
if changed_offsets is None:
changed_offsets = set()
for other in others:
changed_offsets |= self.changed_bytes(other, page_addr)
all_pages: List["ListPage"] = [self] + others
if merge_conditions is None:
merge_conditions = [None] * len(all_pages)
merged_to = None
merged_objects = set()
merged_offsets = set()
for b in sorted(changed_offsets):
if merged_to is not None and not b >= merged_to:
l.info("merged_to = %d ... already merged byte 0x%x", merged_to, b)
continue
l.debug("... on byte 0x%x", b)
memory_objects = []
unconstrained_in = []
# first get a list of all memory objects at that location, and
# all memories that don't have those bytes
for sm, fv in zip(all_pages, merge_conditions):
if sm._contains(b, page_addr):
l.info("... present in %s", fv)
memory_objects.append((sm.content[b], fv))
else:
l.info("... not present in %s", fv)
unconstrained_in.append((sm, fv))
mos = {mo for mo, _ in memory_objects}
mo_bases = {mo.base for mo, _ in memory_objects}
mo_lengths = {mo.length for mo, _ in memory_objects}
endnesses = {mo.endness for mo in mos}
if not unconstrained_in and not (mos - merged_objects): # pylint:disable=superfluous-parens
continue
# first, optimize the case where we are dealing with the same-sized memory objects
if len(mo_bases) == 1 and len(mo_lengths) == 1 and not unconstrained_in and len(endnesses) == 1:
the_endness = next(iter(endnesses))
to_merge = [(mo.object, fv) for mo, fv in memory_objects]
# Update `merged_to`
mo_base = list(mo_bases)[0]
mo_length = memory_objects[0][0].length
size = mo_length - (page_addr + b - mo_base)
merged_to = b + size
merged_val = self._merge_values(to_merge, mo_length, memory=memory)
if merged_val is None:
# merge_values() determines that we should not attempt to merge this value
continue
# do the replacement
# TODO: Implement in-place replacement instead of calling store()
# new_object = self._replace_memory_object(our_mo, merged_val, page_addr, memory.page_size)
if isinstance(memory_objects[0][0], SimLabeledMemoryObject):
labels = [
(mo_.label if isinstance(mo_, SimLabeledMemoryObject) else {}) for mo_, _ in memory_objects
]
merged_label = self._merge_labels(labels, memory=memory)
new_mo = SimLabeledMemoryObject(merged_val, mo_base, endness=the_endness, label=merged_label)
else:
new_mo = SimMemoryObject(merged_val, mo_base, endness=the_endness)
self.store(b, new_mo, size=size, cooperate=True)
# merged_objects.add(new_object)
# merged_objects.update(mos)
merged_offsets.add(b)
else:
# get the size that we can merge easily. This is the minimum of
# the size of all memory objects and unallocated spaces.
min_size = min([mo.length - (b + page_addr - mo.base) for mo, _ in memory_objects])
for um, _ in unconstrained_in:
for i in range(0, min_size):
if um._contains(b + i, page_addr):
min_size = i
break
merged_to = b + min_size
l.info("... determined minimum size of %d", min_size)
# Now, we have the minimum size. We'll extract/create expressions of that
# size and merge them
extracted = (
[(mo.bytes_at(page_addr + b, min_size), fv) for mo, fv in memory_objects] if min_size != 0 else []
)
created = [
(self._default_value(None, min_size, name=f"merge_uc_{uc.id}_{b:x}", memory=memory), fv)
for uc, fv in unconstrained_in
]
to_merge = extracted + created
merged_val = self._merge_values(to_merge, min_size, memory=memory)
if merged_val is None:
continue
if isinstance(memory_objects[0][0], SimLabeledMemoryObject):
labels = [
(mo_.label if isinstance(mo_, SimLabeledMemoryObject) else {}) for mo_, _ in memory_objects
]
merged_label = self._merge_labels(labels, memory=memory)
new_mo = SimLabeledMemoryObject(merged_val, page_addr + b, endness="Iend_BE", label=merged_label)
else:
new_mo = SimMemoryObject(merged_val, page_addr + b, endness="Iend_BE")
self.store(
b, new_mo, size=min_size, endness="Iend_BE", cooperate=True
) # do not convert endianness again
merged_offsets.add(b)
self.stored_offset |= merged_offsets
return merged_offsets
[docs] def changed_bytes(self, other: "ListPage", page_addr: int = None):
candidates = super().changed_bytes(other)
if candidates is None:
candidates: Set[int] = set()
if self.sinkhole is None:
candidates |= self.stored_offset
else:
for i in range(len(self.content)):
if self._contains(i, page_addr):
candidates.add(i)
if other.sinkhole is None:
candidates |= other.stored_offset
else:
for i in range(len(other.content)):
if other._contains(i, page_addr):
candidates.add(i)
byte_width = 8 # TODO: Introduce self.state if we want to use self.state.arch.byte_width
differences: Set[int] = set()
for c in candidates:
s_contains = self._contains(c, page_addr)
o_contains = other._contains(c, page_addr)
if not s_contains and o_contains:
differences.add(c)
elif s_contains and not o_contains:
differences.add(c)
else:
if self.content[c] is None:
self.content[c] = SimMemoryObject(
self.sinkhole.bytes_at(page_addr + c, 1),
page_addr + c,
byte_width=byte_width,
endness="Iend_BE",
)
if other.content[c] is None:
other.content[c] = SimMemoryObject(
other.sinkhole.bytes_at(page_addr + c, 1),
page_addr + c,
byte_width=byte_width,
endness="Iend_BE",
)
if s_contains and self.content[c] != other.content[c]:
same = None
if self._mo_cmp is not None:
same = self._mo_cmp(self.content[c], other.content[c], page_addr + c, 1)
if same is None:
# Try to see if the bytes are equal
self_byte = self.content[c].bytes_at(page_addr + c, 1)
other_byte = other.content[c].bytes_at(page_addr + c, 1)
same = self_byte is other_byte
if same is False:
differences.add(c)
else:
# this means the byte is in neither memory
pass
return differences
def _contains(self, off: int, page_addr: int):
if off >= len(self.content):
return False
if self.content[off] is not None:
return True
if self.sinkhole is None:
return False
return self.sinkhole.includes(page_addr + off)
def _replace_mo(
self, old_mo: SimMemoryObject, new_mo: SimMemoryObject, page_addr: int, page_size: int
) -> SimMemoryObject:
if self.sinkhole is old_mo:
self.sinkhole = new_mo
else:
start, end = self._resolve_range(old_mo, page_addr, page_size)
for i in range(start, end):
if self.content[i - page_addr] is old_mo:
self.content[i - page_addr] = new_mo
return new_mo
@staticmethod
def _resolve_range(mo: SimMemoryObject, page_addr: int, page_size) -> Tuple[int, int]:
start = max(mo.base, page_addr)
end = min(mo.last_addr + 1, page_addr + page_size)
if end <= start:
l.warning("Nothing left of the memory object to store in SimPage.")
return start, end
def _get_object(self, start: int, page_addr: int) -> Optional[SimMemoryObject]:
mo = self.content[start]
if mo is None:
return None
if mo.includes(start + page_addr):
return mo
return None