Files
OSACA/osaca/semantics/marker_utils.py
2019-08-13 18:26:48 +02:00

86 lines
3.2 KiB
Python
Executable File

#!/usr/bin/env python3
from osaca.parser import ParserAArch64v81, ParserX86ATT
def reduce_to_section(kernel, isa):
isa = isa.lower()
if isa == 'x86':
start, end = find_marked_kernel_x86ATT(kernel)
elif isa == 'aarch64':
start, end = find_marked_kernel_AArch64(kernel)
else:
raise ValueError('ISA not supported.')
if start == -1:
raise LookupError('Could not find START MARKER. Make sure it is inserted!')
if end == -1:
raise LookupError('Could not find END MARKER. Make sure it is inserted!')
return kernel[start:end]
def find_marked_kernel_AArch64(lines):
nop_bytes = ['213', '3', '32', '31']
return find_marked_kernel(
lines, ParserAArch64v81(), ['mov'], 'x1', [111, 222], nop_bytes, reverse=True
)
def find_marked_kernel_x86ATT(lines):
nop_bytes = ['100', '103', '144']
return find_marked_kernel(lines, ParserX86ATT(), ['mov', 'movl'], 'ebx', [111, 222], nop_bytes)
def find_marked_kernel(lines, parser, mov_instr, mov_reg, mov_vals, nop_bytes, reverse=False):
index_start = -1
index_end = -1
for i, line in enumerate(lines):
try:
if line.instruction in mov_instr and lines[i + 1].directive is not None:
source = line.operands[0 if not reverse else 1]
destination = line.operands[1 if not reverse else 0]
# instruction pair matches, check for operands
if (
'immediate' in source
and parser.normalize_imd(source.immediate) == mov_vals[0]
and 'register' in destination
and parser.get_full_reg_name(destination.register) == mov_reg
):
# operands of first instruction match start, check for second one
match, line_count = match_bytes(lines, i + 1, nop_bytes)
if match:
# return first line after the marker
index_start = i + 1 + line_count
elif (
'immediate' in source
and parser.normalize_imd(source.immediate) == mov_vals[1]
and 'register' in destination
and parser.get_full_reg_name(destination.register) == mov_reg
):
# operand of first instruction match end, check for second one
match, line_count = match_bytes(lines, i + 1, nop_bytes)
if match:
# return line of the marker
index_end = i
except TypeError:
print(i, line)
if index_start != -1 and index_end != -1:
break
return index_start, index_end
def match_bytes(lines, index, byte_list):
# either all bytes are in one line or in separate ones
extracted_bytes = []
line_count = 0
while (
index < len(lines)
and lines[index].directive is not None
and lines[index].directive.name == 'byte'
):
line_count += 1
extracted_bytes += lines[index].directive.parameters
index += 1
if extracted_bytes[0:len(byte_list)] == byte_list:
return True, line_count
return False, -1