mirror of https://github.com/google/oss-fuzz.git
130 lines
5.0 KiB
Python
Executable File
130 lines
5.0 KiB
Python
Executable File
#!/usr/bin/env python3
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# Copyright 2021 Google LLC
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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################################################################################
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"""Helper script for upgrading a profraw file to latest version."""
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from collections import namedtuple
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import struct
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import subprocess
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import sys
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HeaderGeneric = namedtuple('HeaderGeneric', 'magic version')
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HeaderVersion7 = namedtuple(
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'HeaderVersion7',
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'BinaryIdsSize DataSize PaddingBytesBeforeCounters CountersSize \
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PaddingBytesAfterCounters NamesSize CountersDelta NamesDelta ValueKindLast')
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PROFRAW_MAGIC = 0xff6c70726f667281
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def relativize_address(data, offset, databegin, sect_prf_cnts, sect_prf_data):
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"""Turns an absolute offset into a relative one."""
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value = struct.unpack('Q', data[offset:offset + 8])[0]
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if sect_prf_cnts <= value < sect_prf_data:
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# If the value is an address in the right section, make it relative.
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value = (value - databegin) & 0xffffffffffffffff
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value = struct.pack('Q', value)
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for i in range(8):
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data[offset + i] = value[i]
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def upgrade(data, sect_prf_cnts, sect_prf_data):
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"""Upgrades profraw data, knowing the sections addresses."""
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generic_header = HeaderGeneric._make(struct.unpack('QQ', data[:16]))
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if generic_header.magic != PROFRAW_MAGIC:
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raise Exception('Bad magic.')
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if generic_header.version == 5:
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generic_header = generic_header._replace(version=7)
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# Upgrade from version 5 to 7 by adding binaryids field.
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data = data[:8] + struct.pack('Q', generic_header.version) + struct.pack(
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'Q', 0) + data[16:]
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if generic_header.version < 7:
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raise Exception('Unhandled version.')
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if generic_header.version == 7:
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# cf https://reviews.llvm.org/D111123
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generic_header = generic_header._replace(version=8)
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data = data[:8] + struct.pack('Q', generic_header.version) + data[16:]
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v7_header = HeaderVersion7._make(struct.unpack('QQQQQQQQQ', data[16:88]))
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if v7_header.BinaryIdsSize % 8 != 0:
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# Adds padding for binary ids.
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# cf commit b9f547e8e51182d32f1912f97a3e53f4899ea6be
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# cf https://reviews.llvm.org/D110365
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padlen = 8 - (v7_header.BinaryIdsSize % 8)
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v7_header = v7_header._replace(BinaryIdsSize=v7_header.BinaryIdsSize +
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padlen)
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data = data[:16] + struct.pack('Q', v7_header.BinaryIdsSize) + data[24:]
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data = data[:88 + v7_header.BinaryIdsSize] + bytes(
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padlen) + data[88 + v7_header.BinaryIdsSize:]
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if v7_header.CountersDelta != (sect_prf_cnts -
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sect_prf_data) & 0xffffffffffffffff:
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# Rust linking seems to add an offset...
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sect_prf_data = v7_header.CountersDelta - sect_prf_cnts + sect_prf_data
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sect_prf_cnts = v7_header.CountersDelta
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dataref = sect_prf_data
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relativize_address(data, 64, dataref, sect_prf_cnts, sect_prf_data)
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offset = 88 + v7_header.BinaryIdsSize
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# This also works for C+Rust binaries compiled with
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# clang-14/rust-nightly-clang-13.
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for _ in range(v7_header.DataSize):
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# 16 is the offset of CounterPtr in ProfrawData structure.
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relativize_address(data, offset + 16, dataref, sect_prf_cnts, sect_prf_data)
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# We need this because of CountersDelta -= sizeof(*SrcData);
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# seen in __llvm_profile_merge_from_buffer.
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dataref += 44 + 2 * (v7_header.ValueKindLast + 1)
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# This is the size of one ProfrawData structure.
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offset += 44 + 2 * (v7_header.ValueKindLast + 1)
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return data
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def main():
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"""Helper script for upgrading a profraw file to latest version."""
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if len(sys.argv) != 4:
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sys.stderr.write('Usage: %s <binary> <profraw> <output>\n' % sys.argv[0])
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return 1
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# First find llvm profile sections addresses in the elf, quick and dirty.
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process = subprocess.Popen(['readelf', '-S', sys.argv[1]],
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stdout=subprocess.PIPE)
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output, err = process.communicate()
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if err:
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print('readelf failed')
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return 2
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for line in iter(output.split(b'\n')):
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if b'__llvm_prf_cnts' in line:
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sect_prf_cnts = int(line.split()[3], 16)
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elif b'__llvm_prf_data' in line:
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sect_prf_data = int(line.split()[3], 16)
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# Then open and read the input profraw file.
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with open(sys.argv[2], 'rb') as input_file:
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profraw_base = bytearray(input_file.read())
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# Do the upgrade, returning a bytes object.
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profraw_latest = upgrade(profraw_base, sect_prf_cnts, sect_prf_data)
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# Write the output to the file given to the command line.
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with open(sys.argv[3], 'wb') as output_file:
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output_file.write(profraw_latest)
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return 0
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if __name__ == '__main__':
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sys.exit(main())
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