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Revert "enhance del_mapinfo/change_mapinfo" #1424

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Merged
xwings merged 1 commit into from
Dec 15, 2023
Merged

Revert "enhance del_mapinfo/change_mapinfo" #1424

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133 changes: 22 additions & 111 deletions qiling/os/memory.py
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,6 @@
#

import bisect
import itertools
import os
import re
from typing import Any, Callable, Iterator, List, Mapping, Optional, Pattern, Sequence, Tuple, Union
Expand Down Expand Up @@ -82,8 +81,7 @@ def string(self, addr: int, value=None, encoding='utf-8') -> Optional[str]:
self.__write_string(addr, value, encoding)

def add_mapinfo(self, mem_s: int, mem_e: int, mem_p: int, mem_info: str, is_mmio: bool = False):
"""Add a new memory range to map. Caller must guarantee that
the map info to be added DOES NOT overlap with any existing map infos.
"""Add a new memory range to map.

Args:
mem_s: memory range start
Expand All @@ -95,36 +93,6 @@ def add_mapinfo(self, mem_s: int, mem_e: int, mem_p: int, mem_info: str, is_mmio

bisect.insort(self.map_info, (mem_s, mem_e, mem_p, mem_info, is_mmio))

def find_mapinfo(self, mem_s: int, mem_e: int) -> List[int]:
"""find map infos that overlap with a memory range

Args:
mem_s: memory range start
mem_e: memory range end

Returns: indices of map infos that overlap with the memory range [mem_s, mem_e)
"""

retval = []

# index of first (lbound, ubound, ...) that is >= (mem_s,)
# i.e., lbound >= mem_s
idx = bisect.bisect_left(self.map_info, (mem_s,))

# check the previous one, its lbound is bound to be < mem_s
# so, check its ubound only
if idx > 0 and mem_s < self.map_info[idx - 1][1]:
retval.append(idx - 1)

for i in range(idx, len(self.map_info)):
if self.map_info[i][0] < mem_e:
retval.append(i)
else:
# the lbounds of map infos left are all bound to be >= mem_e, so skip check
break

return retval

def del_mapinfo(self, mem_s: int, mem_e: int):
"""Subtract a memory range from map.

Expand All @@ -133,9 +101,7 @@ def del_mapinfo(self, mem_s: int, mem_e: int):
mem_e: memory range end
"""

overlap_ranges = self.find_mapinfo(mem_s, mem_e)
if len(overlap_ranges) == 0:
return
overlap_ranges = [idx for idx, (lbound, ubound, _, _, _) in enumerate(self.map_info) if (mem_s < ubound) and (mem_e > lbound)]

def __split_overlaps():
for idx in overlap_ranges:
Expand All @@ -148,7 +114,7 @@ def __split_overlaps():
yield (mem_e, ubound, perms, label, is_mmio)

# indices of first and last overlapping ranges. since map info is always
# sorted, we know that all overlapping rages are consecutive, so i1 >= i0
# sorted, we know that all overlapping rages are consecutive, so i1 > i0
i0 = overlap_ranges[0]
i1 = overlap_ranges[-1]

Expand All @@ -160,85 +126,30 @@ def __split_overlaps():
del self.map_info[i0:i1 + 1]

# add new ones
for i, entry in enumerate(new_entries):
self.map_info.insert(i0 + i, entry)
for entry in new_entries:
bisect.insort(self.map_info, entry)

def change_mapinfo(self, mem_s: int, mem_e: int, mem_p: Optional[int] = None, mem_info: Optional[str] = None):
"""Change permissions/labels of a memory range from map.

Args:
mem_s: memory range start
mem_e: memory range end
mem_p: permissions mask, or remain unchanged if None
mem_info: map entry label, or remain unchanged if None
"""
if mem_p is None and mem_info is None:
return # nothing to change, just return
tmp_map_info: Optional[MapInfoEntry] = None
info_idx: int = -1

overlap_ranges = self.find_mapinfo(mem_s, mem_e)
if len(overlap_ranges) == 0:
return

def __split_overlaps():
for idx in overlap_ranges:
lbound, ubound, perms, label, is_mmio = self.map_info[idx]

if (mem_p is None or perms == mem_p) and (mem_info is None or label == mem_info):
# when nothing changed, emit as it is
yield (lbound, ubound, perms, label, is_mmio)
else:
if lbound < mem_s:
yield (lbound, mem_s, perms, label, is_mmio)

new_perms = perms if mem_p is None else mem_p
new_label = label if mem_info is None else mem_info
yield (max(lbound, mem_s), min(ubound, mem_e), new_perms, new_label, is_mmio)

if mem_e < ubound:
yield (mem_e, ubound, perms, label, is_mmio)

def __merge_adjacency(map_infos: Iterator[MapInfoEntry]):
prev: Optional[MapInfoEntry] = None
for current in map_infos:
if prev is None:
prev = current
else:
if prev[1] == current[0] and prev[2:] == current[2:]:
# when prev ubound == current lbound and perms/label/is_mmio are the same, merge current to prev
prev = (prev[0], current[1], prev[2], prev[3], prev[4])
else:
yield prev
prev = current
if prev is not None:
yield prev
for idx, map_info in enumerate(self.map_info):
if mem_s >= map_info[0] and mem_e <= map_info[1]:
tmp_map_info = map_info
info_idx = idx
break

i0 = overlap_ranges[0]
i1 = overlap_ranges[-1]
if tmp_map_info is None:
self.ql.log.error(f'Cannot change mapinfo at {mem_s:#08x}-{mem_e:#08x}')
return

# check if the map info just before overlap_ranges is adjacency to the memory range [mem_s, mem_e)
if 0 < i0 and self.map_info[i0 - 1][1] == mem_s:
i0 -= 1
left_to_merge = [self.map_info[i0]]
else:
left_to_merge = []

# check if the map info just after overlap_ranges is adjacency to the memory range [mem_s, mem_e)
if i1 < len(self.map_info) - 1 and mem_e == self.map_info[i1 + 1][0]:
i1 += 1
right_to_merge = [self.map_info[i1]]
else:
right_to_merge = []

# create new entries by splitting overlapping ranges and merging.
# this has to be done before removing visited entries
new_entries = list(__merge_adjacency(itertools.chain(left_to_merge, __split_overlaps(), right_to_merge)))

# remove visited entries
del self.map_info[i0:i1 + 1]
if mem_p is not None:
self.del_mapinfo(mem_s, mem_e)
self.add_mapinfo(mem_s, mem_e, mem_p, mem_info if mem_info else tmp_map_info[3])
return

# add new ones
for i, entry in enumerate(new_entries):
self.map_info.insert(i0 + i, entry)
if mem_info is not None:
self.map_info[info_idx] = (tmp_map_info[0], tmp_map_info[1], tmp_map_info[2], mem_info, tmp_map_info[4])

def get_mapinfo(self) -> Sequence[Tuple[int, int, str, str, str]]:
"""Get memory map info.
Expand Down Expand Up @@ -508,8 +419,8 @@ def unmap(self, addr: int, size: int) -> None:
size: range size (in bytes)
"""

self.ql.uc.mem_unmap(addr, size)
self.del_mapinfo(addr, addr + size)
self.ql.uc.mem_unmap(addr, size)

if (addr, addr + size) in self.mmio_cbs:
del self.mmio_cbs[(addr, addr+size)]
Expand Down