diff mbox

[v1,15/22] target-arm: A64: Forbid ERET to increase the EL

Message ID 1399356506-5609-16-git-send-email-edgar.iglesias@gmail.com
State New
Headers show

Commit Message

Edgar E. Iglesias May 6, 2014, 6:08 a.m. UTC 
From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 target-arm/op_helper.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Peter Crosthwaite May 7, 2014, 6:03 a.m. UTC | #1 
On Tue, May 6, 2014 at 4:08 PM, Edgar E. Iglesias
<edgar.iglesias@gmail.com> wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
>
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>

Reviewed-by: Peter Crosthwaite <peter.crosthwaite@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 dd9e4fc..770c776 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 = arm64_banked_spsr_index(1);
>      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[ELR_EL_IDX(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
>
>
diff mbox

Patch

diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index dd9e4fc..770c776 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 = arm64_banked_spsr_index(1);
     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[ELR_EL_IDX(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;