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# Copyright (C) 2011 by jedi95 <jedi95@gmail.com> and
# CFSworks <CFSworks@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
import struct
class PatchError(Exception): pass
class BFIPatcher(object):
"""Patches .ELF files compiled for Evergreen GPUs; changes the microcode
so that any BYTE_ALIGN_INT instructions become BFI_INT.
"""
def __init__(self, interface):
self.interface = interface
def patch(self, data):
"""Run the process of patching an ELF."""
self.interface.debug('Finding inner ELF...')
innerPos = self.locateInner(data)
self.interface.debug('Patching inner ELF...')
inner = data[innerPos:]
patched = self.patchInner(inner)
self.interface.debug('Patch complete, returning to kernel...')
return data[:innerPos] + patched
def patchInner(self, data):
sections = self.readELFSections(data)
# We're looking for .text -- there should be two of them.
textSections = filter(lambda x: x[0] == '.text', sections)
if len(textSections) != 2:
self.interface.debug('Inner ELF does not have 2 .text sections!')
self.interface.debug('Sections are: %r' % sections)
raise PatchError()
name, offset, size = textSections[1]
before, text2, after = (data[:offset], data[offset:offset+size],
data[offset+size:])
self.interface.debug('Patching instructions...')
text2 = self.patchInstructions(text2)
return before + text2 + after
def patchInstructions(self, data):
output = ''
nPatched = 0
for i in xrange(len(data)/8):
inst, = struct.unpack('Q', data[i*8:i*8+8])
# Is it BYTE_ALIGN_INT?
if (inst&0x9003f00002001000) == 0x0001a00000000000:
nPatched += 1
inst ^= (0x0001a00000000000 ^ 0x0000c00000000000) # BFI_INT
output += struct.pack('Q', inst)
self.interface.debug('BFI-patched %d instructions...' % nPatched)
if nPatched < 60:
self.interface.debug('Patch safety threshold not met!')
raise PatchError()
return output
def locateInner(self, data):
"""ATI uses an ELF-in-an-ELF. I don't know why. This function's job is
to find it.
"""
pos = data.find('\x7fELF', 1)
if pos == -1 or data.find('\x7fELF', pos+1) != -1: # More than 1 is bad
self.interface.debug('Inner ELF not located!')
raise PatchError()
return pos
def readELFSections(self, data):
try:
(ident1, ident2, type, machine, version, entry, phoff,
shoff, flags, ehsize, phentsize, phnum, shentsize, shnum,
shstrndx) = struct.unpack('QQHHIIIIIHHHHHH', data[:52])
if ident1 != 0x64010101464c457f:
self.interface.debug('Invalid ELF header!')
raise PatchError()
# No section header?
if shoff == 0:
return []
# Find out which section contains the section header names
shstr = data[shoff+shstrndx*shentsize:shoff+(shstrndx+1)*shentsize]
(nameIdx, type, flags, addr, nameTableOffset, size, link, info,
addralign, entsize) = struct.unpack('IIIIIIIIII', shstr)
# Grab the section header.
sh = data[shoff:shoff+shnum*shentsize]
sections = []
for i in xrange(shnum):
rawEntry = sh[i*shentsize:(i+1)*shentsize]
(nameIdx, type, flags, addr, offset, size, link, info,
addralign, entsize) = struct.unpack('IIIIIIIIII', rawEntry)
nameOffset = nameTableOffset + nameIdx
name = data[nameOffset:data.find('\x00', nameOffset)]
sections.append((name, offset, size))
return sections
except struct.error:
self.interface.debug('A struct.error occurred while reading ELF!')
raise PatchError()
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