def applyRelocs(elf, vw, addbase=False, baseaddr=0):
# process relocations / strings (relocs use Dynamic Symbols)
arch = arch_names.get(elf.e_machine)
relocs = elf.getRelocs()
logger.debug("reloc len: %d", len(relocs))
for r in relocs:
rtype = Elf.getRelocType(r.r_info)
rlva = r.r_offset
if addbase:
rlva += baseaddr
try:
# If it has a name, it's an externally
# resolved "import" entry, otherwise, just a regular reloc
name = r.getName()
dmglname = demangle(name)
logger.debug('relocs: 0x%x: %r (%r)', rlva, dmglname, name)
if arch in ('i386', 'amd64'):
if name:
if rtype == Elf.R_X86_64_IRELATIVE:
# before making import, let's fix up the pointer as a BASEPTR Relocation
ptr = r.r_addend
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
logger.info('Reloc: R_X86_64_IRELATIVE 0x%x', rlva)
if rtype in (Elf.R_386_JMP_SLOT, Elf.R_X86_64_GLOB_DAT, Elf.R_X86_64_IRELATIVE):
logger.info('Reloc: making Import 0x%x (name: %s/%s) ', rlva, name, dmglname)
vw.makeImport(rlva, "*", dmglname)
vw.setComment(rlva, name)
elif rtype in (Elf.R_386_32, Elf.R_386_COPY):
pass
else:
logger.warn('unknown reloc type: %d %s (at %s)', rtype, name, hex(rlva))
logger.info(r.tree())
else:
symidx = Elf.getRelocSymTabIndex(r.r_info)
sym = elf.getDynSymbol(symidx)
ptr = sym.st_value
if rtype == Elf.R_386_RELATIVE: # R_X86_64_RELATIVE is the same number
ptr = vw.readMemoryPtr(rlva)
logger.info('R_386_RELATIVE: adding Relocation 0x%x -> 0x%x (name: %s) ', rlva, ptr, dmglname)
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
elif rtype == Elf.R_X86_64_IRELATIVE:
# first make it a relocation that is based on the imagebase
ptr = r.r_addend
logger.info('R_X86_64_IRELATIVE: adding Relocation 0x%x -> 0x%x (name: %r %r) ', rlva, ptr, name, dmglname)
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
# next get the target and find a name, since the reloc itself doesn't have one
tgt = vw.readMemoryPtr(rlva)
tgtname = vw.getName(tgt)
if tgtname is not None:
logger.info(' name(0x%x): %r', tgt, tgtname)
fn, symname = tgtname.split('.', 1)
logger.info('Reloc: making Import 0x%x (name: %s.%s) ', rlva, fn, symname)
vw.makeImport(rlva, fn, symname)
else:
logger.warn('unknown reloc type: %d %s (at %s)', rtype, name, hex(rlva))
logger.info(r.tree())
if arch in ('arm', 'thumb', 'thumb16'):
if rtype == Elf.R_ARM_JUMP_SLOT:
symidx = Elf.getRelocSymTabIndex(r.r_info)
sym = elf.getDynSymbol(symidx)
ptr = sym.st_value
#quick check to make sure we don't provide this symbol
if ptr:
logger.info('R_ARM_JUMP_SLOT: adding Relocation 0x%x -> 0x%x (%s) ', rlva, ptr, dmglname)
if addbase:
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
else:
vw.addRelocation(rlva, vivisect.RTYPE_BASERELOC, ptr)
pname = "ptr_%s_%.8x" % (name, rlva)
if vw.vaByName(pname) is None:
vw.makeName(rlva, pname)
if addbase:
ptr += baseaddr
vw.makeName(ptr, name)
vw.setComment(ptr, dmglname)
else:
logger.info('R_ARM_JUMP_SLOT: adding Import 0x%x (%s) ', rlva, dmglname)
vw.makeImport(rlva, "*", dmglname)
vw.setComment(rlva, name)
elif rtype == Elf.R_ARM_GLOB_DAT:
symidx = Elf.getRelocSymTabIndex(r.r_info)
sym = elf.getDynSymbol(symidx)
ptr = sym.st_value
#quick check to make sure we don't provide this symbol
if ptr:
logger.info('R_ARM_GLOB_DAT: adding Relocation 0x%x -> 0x%x (%s) ', rlva, ptr, dmglname)
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
pname = "ptr_%s" % name
if vw.vaByName(pname) is None:
vw.makeName(rlva, pname)
if addbase:
ptr += baseaddr
vw.makeImport(ptr, "*", dmglname)
vw.setComment(ptr, name)
else:
logger.info('R_ARM_GLOB_DAT: adding Import 0x%x (%s) ', rlva, dmglname)
vw.makeImport(rlva, "*", dmglname)
vw.setComment(rlva, name)
elif rtype == Elf.R_ARM_ABS32:
symidx = Elf.getRelocSymTabIndex(r.r_info)
sym = elf.getDynSymbol(symidx)
ptr = sym.st_value
if ptr:
logger.info('R_ARM_ABS32: adding Relocation 0x%x -> 0x%x (%s) ', rlva, ptr, dmglname)
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
pname = "ptr_%s" % name
if vw.vaByName(pname) is None and len(name):
vw.makeName(rlva, pname)
else:
logger.info('R_ARM_ABS32: adding Import 0x%x (%s) ', rlva, dmglname)
vw.makeImport(rlva, "*", dmglname)
vw.setComment(rlva, name)
vw.setComment(rlva, dmglname)
elif rtype == Elf.R_ARM_RELATIVE: # Adjust locations for the rebasing
ptr = vw.readMemoryPtr(rlva)
logger.info('R_ARM_RELATIVE: adding Relocation 0x%x -> 0x%x (name: %s) ', rlva, ptr, dmglname)
vw.addRelocation(rlva, vivisect.RTYPE_BASEPTR, ptr)
if len(name):
vw.makeName(rlva, dmglname, makeuniq=True)
vw.setComment(rlva, name)
else:
logger.warn('unknown reloc type: %d %s (at %s)', rtype, name, hex(rlva))
logger.info(r.tree())
except vivisect.InvalidLocation as e:
logger.warn("NOTE\t%r", e)
