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Update mod_utils.py #2

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Update mod_utils.py #2

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47 changes: 34 additions & 13 deletions mod_utils.py
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Original file line number Diff line number Diff line change
Expand Up @@ -32,15 +32,18 @@ def patch_gen(instrs, loc_db, nop_addrs, link):
#omitting useless instructions
if instr.offset not in nop_addrs:
if instr.is_subcall():
#generate asm for fixed calls with relative addrs
patch_addr = start_addr + len(final_patch)
tgt = loc_db.get_location_offset(instr.args[0].loc_key)
_log.info("CALL %#x" % tgt)
call_patch_str = "CALL %s" % rel(tgt, patch_addr)
_log.debug("call patch : %s" % call_patch_str)
call_patch = asmb(call_patch_str, loc_db)
final_patch += call_patch
_log.debug("call patch asmb : %s" % encode_hex(call_patch))
if isinstance(instr.args[0],ExprMem) or isinstance(instr.args[0],ExprId):
final_patch += instr.b
else:
#generate asm for fixed calls with relative addrs
patch_addr = start_addr + len(final_patch)
tgt = loc_db.get_location_offset(instr.args[0].loc_key)
_log.info("CALL %#x" % tgt)
call_patch_str = "CALL %s" % rel(tgt, patch_addr)
_log.debug("call patch : %s" % call_patch_str)
call_patch = asmb(call_patch_str, loc_db)
final_patch += call_patch
_log.debug("call patch asmb : %s" % encode_hex(call_patch))
else:
#add the original bytes
final_patch += instr.b
Expand Down Expand Up @@ -115,7 +118,7 @@ def get_block_father(asmcfg, blk_offset):
return asmcfg.loc_db.get_location_offset(checklist[-1])


def get_phi_vars(ircfg):
def get_phi_vars(ircfg,loc_db,mdis):
res = []
blks = list(ircfg.blocks)
irblock = (ircfg.blocks[blks[-1]])
Expand All @@ -133,13 +136,22 @@ def get_phi_vars(ircfg):
irblock = ircfg.get_block(list(loc)[0])
for asg in irblock:
dst, src = asg.items()[0]
if dst == var:
if dst == var and isinstance(src,ExprInt):
res += [int(src)]
elif dst==var and isinstance(src,ExprOp):
reachings = ReachingDefinitions(ircfg)
digraph = DiGraphDefUse(reachings)
# the state var always a leaf
for head in digraph.heads():
if head.var == src.args[0]:
head_offset=loc_db.get_location_offset(head.label)
if isinstance(mdis.dis_instr(head_offset).args[1],ExprInt):
res+=[int(mdis.dis_instr(head_offset).args[1])]

return res


def find_var_asg(ircfg, var):
def find_var_asg(ircfg, var,loc_db,mdis):
val_list = []
res = {}
for lbl, irblock in viewitems(ircfg.blocks):
Expand All @@ -153,7 +165,16 @@ def find_var_asg(ircfg, var):
res['next'] = int(src)
val_list += [int(src)]
elif isinstance(src, ExprSlice):
phi_vals = get_phi_vars(ircfg)
phi_vals = get_phi_vars(ircfg,loc_db,mdis)
if not phi_vals:
continue
res['true_next'] = phi_vals[0]
res['false_next'] = phi_vals[1]
val_list += phi_vals
elif isinstance(src,ExprId):
phi_vals = get_phi_vars(ircfg,None,None)
if not phi_vals:
continue
res['true_next'] = phi_vals[0]
res['false_next'] = phi_vals[1]
val_list += phi_vals
Expand Down