Emulator Arm SP register fix (#2337)

* new register list to extract flags

* lint

* lint2

* list order

* remove stale comment

* fix

* disable debug mode...

* Fix with specific register ordering

* Add reference to pr

* remove debug statement

* cache order on registerset

* lint

* list -> List

pwndbg/emu/emulator.py

@@ -221,11 +221,7 @@ class Emulator:
         self.last_single_step_result = InstructionExecutedResult(None, None)
 
         # Initialize the register state
-        for reg in (
-            list(self.regs.retaddr)
-            + list(self.regs.misc)
-            + list(self.regs.common)  # this includes the flags register
-        ):
+        for reg in self.regs.emulated_regs_order:
             enum = self.get_reg_enum(reg)
 
             if not reg:

pwndbg/lib/regs.py

@@ -80,6 +80,17 @@ class RegisterSet:
             if reg and reg not in self.common:
                 self.common.append(reg)
 
+        # The specific order of this list is very important:
+        # Due to the behavior of Arm in the Unicorn engine,
+        # we must write the flags register after PC, and the stack pointer after the flags register.
+        # Otherwise, the values will be clobbered
+        # https://github.com/pwndbg/pwndbg/pull/2337
+        self.emulated_regs_order: List[str] = []
+
+        for reg in [pc] + list(flags) + [stack, frame] + list(retaddr) + list(misc) + list(gpr):
+            if reg and reg not in self.emulated_regs_order:
+                self.emulated_regs_order.append(reg)
+
         self.all = set(misc) | set(flags) | set(extra_flags) | set(self.retaddr) | set(self.common)
         self.all -= {None}