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Arm64 #726

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1 change: 1 addition & 0 deletions volatility/dwarf.py
Expand Up @@ -50,6 +50,7 @@ class DWARFParser(object):
'unsigned int': 'unsigned int',
'sizetype' : 'unsigned long',
'ssizetype' : 'long',
'__int128 unsigned': 'unsigned long long',
}


Expand Down
143 changes: 143 additions & 0 deletions volatility/plugins/addrspaces/arm64.py
@@ -0,0 +1,143 @@
# Volatility
#
# This file is part of Volatility.
#
# Volatility is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Volatility is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Volatility. If not, see <http://www.gnu.org/licenses/>.
#

import struct
import volatility.obj as obj
import volatility.debug as debug #pylint: disable-msg=W0611
import volatility.plugins.addrspaces.paged as paged


class AbstractArm64AddressSpace(paged.AbstractWritablePagedMemory):
"""Address space for ARM64 processors"""

order = 800
pae = False
paging_address_space = True
checkname = 'Arm64ValidAS'
minimum_size = 0x1000
alignment_gcd = 0x1000
_longlong_struct = struct.Struct('<Q')
_valid_dtb_base = None

def read_longlong_phys(self, addr):
'''
Returns an unsigned 64-bit integer from the address addr in
physical memory. If unable to read from that location, returns None.
'''
try:
string = self.base.read(addr, 8)
except IOError:
string = None
if not string:
return obj.NoneObject("Could not read_longlong_phys at offset " + hex(addr))
longlongval, = self._longlong_struct.unpack(string)
return longlongval

def ptbl_lowbits(self, level):
return 3 + (self.pgtable_level_bits) * (4 - level)

def ptbl_index(self, vaddr, level):
return (vaddr >> self.ptbl_lowbits(level)) & ((1 << self.pgtable_level_bits) - 1)

def ptbl_walk(self, vaddr, base):
if (vaddr == 0):
return None

# 4KB pages will further mask only 48 bits using ptbl_index
vaddr = vaddr & ((1 << 52) - 1)

for level in xrange(self.pgtable_level_start, 4):
index = self.ptbl_index(vaddr, level)
entry = self.read_longlong_phys(base + (index << 3))
debug.debug("level: {0:d} index: {1:3x} base: {2:16x} entry {3:16x}".format(level, index, base, entry), 4)
if not entry:
return None
entry_addressbits = entry & self._entry_addressmask
# entry not valid
if not (entry & 0x1):
return None
if (level == 3 and (entry & 0x3 != 0x3)):
return None
# entry points to final address
if (level == 3 or (entry & 0x3 == 0x1)):
lowbitmask = (1 << self.ptbl_lowbits(level)) - 1
result = entry_addressbits & (~lowbitmask) | (vaddr & lowbitmask)
debug.debug("-result {0:16x}".format(result), 4)
return result
# entry points to next table
base = entry_addressbits
return None

def vtop(self, vaddr):
debug.debug("\n--vtop start: {0:x}".format(vaddr), 4)

# if we already had a valid dtb - it was the single TTBR1, and should
# be used to translate all kernel-space
if type(self)._valid_dtb_base and (vaddr >> 63):
return self.ptbl_walk(vaddr, type(self)._valid_dtb_base)
else:
return self.ptbl_walk(vaddr, self.dtb)

def set_curr_base_valid(self):
cls = type(self)
if not cls._valid_dtb_base:
cls._valid_dtb_base = self.dtb

def get_available_pages(self):
level = self.pgtable_level_start
ptbl_descs = [self.dtb, 0, 0, 0]
ptbl_indexes = [0, 0, 0, 0]
while True:
if ptbl_indexes[level] == 1 << self.pgtable_level_bits:
if level == self.pgtable_level_start:
break
level -= 1
ptbl_indexes[level] += 1
continue

entry = self.read_longlong_phys(ptbl_descs[level] + (ptbl_indexes[level] << 3))

# entry points to next table
if ((level < 3) and (entry & 0x3 == 0x3)):
level += 1
entry_addressbits = entry & self._entry_addressmask
ptbl_descs[level] = entry_addressbits
ptbl_indexes[level] = 0
continue

# entry points to physical address
if (level == 3 and (entry & 0x3 == 0x3)) or (entry & 0x3 == 0x1):
vaddr = 0
for ilvl in xrange(level+1):
vaddr += ptbl_indexes[ilvl] << self.ptbl_lowbits(ilvl)
yield vaddr, (1 << self.ptbl_lowbits(level))

ptbl_indexes[level] += 1


# 4-level , 4KB pagetable
class Arm64AddressSpace_4KB(AbstractArm64AddressSpace):
pgtable_level_bits = 9
_entry_addressmask = ((1 << 48) - 1) & (~((1 << 12) - 1))
pgtable_level_start = 0

# 3-level 64KB pagetable, for kernel compiled with CONFIG_ARM64_PA_BITS_52
class Arm64AddressSpace_64KB(AbstractArm64AddressSpace):
pgtable_level_bits = 13
_entry_addressmask = ((1 << 48) - 1) & (~((1 << 16) - 1))
pgtable_level_start = 1
43 changes: 37 additions & 6 deletions volatility/plugins/overlays/linux/linux.py
Expand Up @@ -120,6 +120,7 @@ def is_writable(self):
'ArmValidAS' : [ 0x0, ['VolatilityLinuxARMValidAS']],
'IA32ValidAS' : [ 0x0, ['VolatilityLinuxIntelValidAS']],
'AMD64ValidAS' : [ 0x0, ['VolatilityLinuxIntelValidAS']],
'Arm64ValidAS' : [ 0x0, ['VolatilityLinuxARM64ValidAS']],
}],
'vm_area_struct' : [ None, {
'vm_flags' : [ None, ['LinuxPermissionFlags', {'bitmap': {'r': 0, 'w': 1, 'x': 2}}]],
Expand Down Expand Up @@ -156,6 +157,9 @@ def parse_system_map(data, module):
if symbol == "arm_syscall":
arch = "ARM"

if symbol == "arm64_dma_phys_limit":
arch = "arm64"

if not symbol in sys_map[module]:
sys_map[module][symbol] = []

Expand Down Expand Up @@ -192,9 +196,6 @@ def LinuxProfileFactory(profpkg):
sysmapdata = profpkg.read(f.filename)
arch, memmodel, sysmap = parse_system_map(profpkg.read(f.filename), "kernel")

if memmodel == "64bit":
arch = "x64"

if not sysmapdata or not dwarfdata:
# Might be worth throwing an exception here?
return None
Expand Down Expand Up @@ -2330,7 +2331,12 @@ def generate_suggestions(self):
config = self.obj_vm.get_config()
tbl = self.obj_vm.profile.sys_map["kernel"]

if profile.metadata.get('memory_model', '32bit') == "32bit":
if profile.metadata.get('arch') == 'arm64':
sym = "swapper_pg_dir"
shifts = [0xffff000000000000, 0xffff800000000000]
read_sz = 8
fmt = "<Q"
elif profile.metadata.get('memory_model', '32bit') == "32bit":
sym = "swapper_pg_dir"
shifts = [0xc0000000]
read_sz = 4
Expand Down Expand Up @@ -2415,8 +2421,9 @@ def generate_suggestions(self):

good_dtb = (dtb_sym_addr - shifts[0] + 0) + tmp_physical_shift

if pas.zread(good_dtb, 8) != "\x00\x00\x00\x00\x00\x00\x00\x00":
continue
if profile.metadata.get('arch') != 'arm64':
if pas.zread(good_dtb, 8) != "\x00\x00\x00\x00\x00\x00\x00\x00":
continue

if sched_class_offset != -1:
sched_class_val = pas.read(swapper_address + sched_class_offset, read_sz)
Expand Down Expand Up @@ -2493,6 +2500,29 @@ def generate_suggestions(self):

yield fork_off - task_off == sym_addr_diff

class VolatilityLinuxARM64ValidAS(obj.VolatilityMagic):
"""An object to check that an address space is a valid Arm64 Paged space"""
def generate_suggestions(self):

init_task_addr = self.obj_vm.profile.get_symbol("init_task")
do_fork_addr = self.obj_vm.profile.get_symbol("_do_fork")

if not do_fork_addr or not init_task_addr:
return

task_paddr = self.obj_vm.vtop(init_task_addr)
do_fork_paddr = self.obj_vm.vtop(do_fork_addr)

if not do_fork_paddr or not task_paddr:
return

res = (do_fork_paddr - task_paddr == do_fork_addr - init_task_addr)

if res:
self.obj_vm.set_curr_base_valid()

yield res

class LinuxObjectClasses(obj.ProfileModification):
conditions = {'os': lambda x: x == 'linux'}
before = ['BasicObjectClasses']
Expand All @@ -2518,6 +2548,7 @@ def modification(self, profile):
'Ipv6Address': basic.Ipv6Address,
'VolatilityLinuxIntelValidAS' : VolatilityLinuxIntelValidAS,
'VolatilityLinuxARMValidAS' : VolatilityLinuxARMValidAS,
'VolatilityLinuxARM64ValidAS' : VolatilityLinuxARM64ValidAS,
'kernel_param' : kernel_param,
'kparam_array' : kparam_array,
'desc_struct' : desc_struct,
Expand Down