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Fix registers' retrieval. #4

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Fix registers' retrieval. #4

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50 changes: 29 additions & 21 deletions crash/arch/x86_64.py
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,13 @@
class x86_64Architecture(CrashArchitecture):
ident = "i386:x86-64"
aliases = [ "x86_64" ]
# register position on stack (in the future, this should be generated
# dynamically)
stackregs = {"rbx": 1,
"r12": 2,
"r13": 3,
"r14": 4,
"r15": 5}

def __init__(self):
# PC for blocked threads
Expand All @@ -23,7 +30,7 @@ def setup_thread_info(self, thread):
def fetch_register_active(self, thread, register):
task = thread.info
for reg in task.regs:
if reg == "rip" and (register != 16 and register != -1):
if reg == "rip" and (register.name != "rip"):
continue
if reg in ["gs_base", "orig_ax", "rflags", "fs_base"]:
continue
Expand All @@ -32,40 +39,41 @@ def fetch_register_active(self, thread, register):
def fetch_register_scheduled(self, thread, register):
ulong_type = self.ulong_type
task = thread.info.task_struct
r = register.name

# Only write rip when requested; It resets the frame cache
if register == 16 or register == -1:
if r == 'rip':
thread.registers['rip'].value = self.rip
if register == 16:
return True
return True

rsp = task['thread']['sp'].cast(ulong_type.pointer())
rbp = rsp.dereference().cast(ulong_type.pointer())
rbx = (rbp - 1).dereference()
r12 = (rbp - 2).dereference()
r13 = (rbp - 3).dereference()
r14 = (rbp - 4).dereference()
r15 = (rbp - 5).dereference()

# The two pushes that don't have CFI info
if r in self.stackregs:
thread.registers[r].value = (rbp - self.stackregs[r]).dereference()
elif r == 'rsp':
thread.registers[r].value = rsp
thread.info.stack_pointer = rsp
thread.info.valid_stack = True
elif r == 'rbp':
thread.registers[r].value = rbp

# The two pushes that don't have CFI info
# rsp += 2

# ex = in_exception_stack(rsp)
# if ex:
# print "EXCEPTION STACK: pid %d" % task['pid']

thread.registers['rsp'].value = rsp
thread.registers['rbp'].value = rbp
thread.registers['rbx'].value = rbx
thread.registers['r12'].value = r12
thread.registers['r13'].value = r13
thread.registers['r14'].value = r14
thread.registers['r15'].value = r15
thread.registers['cs'].value = 2*8
thread.registers['ss'].value = 3*8
elif r == 'cs':
thread.registers['cs'].value = 2*8
elif r == 'ss':
thread.registers['ss'].value = 3*8
else:
gdb.write("wanted register %s\n" % r)
return False

thread.info.stack_pointer = rsp
thread.info.valid_stack = True
return True

def get_stack_pointer(self, thread):
return long(thread.registers['rsp'].value)
Expand Down
2 changes: 1 addition & 1 deletion crash/kdump/target.py
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Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,7 @@ def to_pid_to_str(self, ptid):

def to_fetch_registers(self, register):
thread = gdb.selected_thread()
self.arch.fetch_register(thread, register.regnum)
self.arch.fetch_register(thread, register)
return True

def to_prepare_to_store(self, thread):
Expand Down