From eaa080e2325233aed4411bd9b85e46f606c53dd5 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Fri, 2 Mar 2018 13:45:55 -0500
Subject: [PATCH] armv7m: set CFSR.UNDEFINSTR on undefined instructions

When we take an exception for an undefined instruction, set the
appropriate CFSR bit.

Backports commit 81dd9648c69bb89afdd6f4bb3ed6f3efdac96524 from qemu
---
 qemu/target/arm/helper.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/qemu/target/arm/helper.c b/qemu/target/arm/helper.c
index a1ef6a96..74fd5db4 100644
--- a/qemu/target/arm/helper.c
+++ b/qemu/target/arm/helper.c
@@ -5443,6 +5443,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
     switch (cs->exception_index) {
     case EXCP_UDEF:
         //armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE);
+        env->v7m.cfsr |= R_V7M_CFSR_UNDEFINSTR_MASK;
         return;
     case EXCP_SWI:
         /* The PC already points to the next instruction.  */