target/arm: Clear exclusive monitor on v7M reset, exception entry/exit

For M profile we must clear the exclusive monitor on reset, exception
entry and exception exit.  We weren't doing any of these things; fix
this bug.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505137930-13255-3-git-send-email-peter.maydell@linaro.org

1 files changed, 2 insertions, 0 deletions

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 329e5178d8..668e3671bd 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6175,6 +6175,7 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr)
 
     armv7m_nvic_acknowledge_irq(env->nvic);
     switch_v7m_sp(env, 0);
+    arm_clear_exclusive(env);
     /* Clear IT bits */
     env->condexec_bits = 0;
     env->regs[14] = lr;
@@ -6354,6 +6355,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
     }
 
     /* Otherwise, we have a successful exception exit. */
+    arm_clear_exclusive(env);
     qemu_log_mask(CPU_LOG_INT, "...successful exception return\n");
 }