Hi, Peter,
Could you take this fix as high priority? This bug has made qemu-system-arm
broken.
On Sat, Mar 28, 2020 at 10:02:32PM +0800, Changbin Du wrote:
> The arm_current_el() should be invoked after mode switching. Otherwise, we
> get a wrong current EL value, since current EL is also determined by
> current mode.
>
> Fixes: 4a2696c0d4 ("target/arm: Set PAN bit as required on exception entry")
> Signed-off-by: Changbin Du <changbin...@gmail.com>
> ---
> target/arm/helper.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index b7b6887241..163c91a1cc 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -9172,7 +9172,6 @@ static void take_aarch32_exception(CPUARMState *env,
> int new_mode,
>
> /* Change the CPU state so as to actually take the exception. */
> switch_mode(env, new_mode);
> - new_el = arm_current_el(env);
>
> /*
> * For exceptions taken to AArch32 we must clear the SS bit in both
> @@ -9184,6 +9183,10 @@ static void take_aarch32_exception(CPUARMState *env,
> int new_mode,
> env->condexec_bits = 0;
> /* Switch to the new mode, and to the correct instruction set. */
> env->uncached_cpsr = (env->uncached_cpsr & ~CPSR_M) | new_mode;
> +
> + /* This must be after mode switching. */
> + new_el = arm_current_el(env);
> +
> /* Set new mode endianness */
> env->uncached_cpsr &= ~CPSR_E;
> if (env->cp15.sctlr_el[new_el] & SCTLR_EE) {
> --
> 2.25.1
>
--
Cheers,
Changbin Du
