From: "Edgar E. Iglesias" <edgar.igles...@xilinx.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.igles...@xilinx.com>
---
target-arm/op_helper.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index c05a839..a6eedb2 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -389,6 +389,7 @@ void HELPER(exception_return)(CPUARMState *env)
unsigned int spsr_idx = is_a64(env) ? aarch64_banked_spsr_index(1) : 0;
uint32_t spsr = env->banked_spsr[spsr_idx];
int new_el, i;
+ int cur_el = arm_current_pl(env);
if (env->pstate & PSTATE_SP) {
env->sp_el[1] = env->xregs[31];
@@ -410,6 +411,10 @@ void HELPER(exception_return)(CPUARMState *env)
env->regs[15] = env->elr_el[1] & ~0x1;
} else {
new_el = extract32(spsr, 2, 2);
+ if (new_el > cur_el) {
+ /* Disallow returns to higher ELs than the current one. */
+ goto illegal_return;
+ }
if (new_el > 1) {
/* Return to unimplemented EL */
goto illegal_return;
--
1.8.3.2
