crash-python
diff --git a/crash/arch/x86_64.py b/crash/arch/x86_64.py
@@ -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
@@ -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
@@ -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)

diff --git a/crash/kdump/target.py b/crash/kdump/target.py
@@ -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):