From 8033781d7f33c4e9c0f016fbbadcfe53088aa664 Mon Sep 17 00:00:00 2001
From: Kurtis Miller <kurtisgmiller@gmail.com>
Date: Thu, 17 Apr 2025 21:51:40 -0500
Subject: [PATCH] ensure Nyx command handler support is more CPU agnostic
 (#3153)

---
 libafl_qemu/src/command/nyx.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libafl_qemu/src/command/nyx.rs b/libafl_qemu/src/command/nyx.rs
index e854c811af5..6eb982caaa3 100644
--- a/libafl_qemu/src/command/nyx.rs
+++ b/libafl_qemu/src/command/nyx.rs
@@ -109,8 +109,8 @@ macro_rules! define_nyx_command_manager {
                 #[deny(unreachable_patterns)]
                 fn parse(&self, qemu: Qemu) -> Result<Self::Commands, CommandError> {
                     let arch_regs_map: &'static EnumMap<ExitArgs, Regs> = get_exit_arch_regs();
-                    let nyx_backdoor = qemu.read_reg(Regs::Rax)? as c_uint;
-                    let cmd_id = qemu.read_reg(Regs::Rbx)? as c_uint;
+                    let nyx_backdoor = qemu.read_reg(arch_regs_map[ExitArgs::Ret])? as c_uint;
+                    let cmd_id = qemu.read_reg(arch_regs_map[ExitArgs::Cmd])? as c_uint;
 
                     // Check nyx backdoor correctness
                     debug_assert_eq!(nyx_backdoor, 0x1f);