[PATCH 69/82] target/arm: Implement EXLOCK check during exception return

[Richard Henderson]

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 target/arm/tcg/helper-a64.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c
index f61adf1f80..7ab7ddf7c4 100644
--- a/target/arm/tcg/helper-a64.c
+++ b/target/arm/tcg/helper-a64.c
@@ -694,6 +694,17 @@ void HELPER(exception_return)(CPUARMState *env, uint64_t 
new_pc)
         goto illegal_return;
     }
 
+    /*
+     * If GetCurrentEXLOCKEN, the exception return path must use GCSPOPCX,
+     * which will set PSTATE.EXLOCK.  We need not explicitly check FEAT_GCS,
+     * because GCSCR_ELx cannot be set without it.
+     */
+    if (new_el == cur_el &&
+        (env->cp15.gcscr_el[cur_el] & GCSCR_EXLOCKEN) &&
+        !(env->pstate & PSTATE_EXLOCK)) {
+        goto illegal_return;
+    }
+
     bql_lock();
     arm_call_pre_el_change_hook(cpu);
     bql_unlock();
-- 
2.43.0