Re: [Qemu-devel] [PATCH 12/13] target/arm: Add v8M stack checks for VLDM/VSTM

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 02/10/2018 18:35, Peter Maydell wrote:
> Add the v8M stack checks for the VLDM/VSTM
> (aka VPUSH/VPOP) instructions. This code is currently
> unreachable because we haven't yet implemented M profile
> floating point support, but since the change is simple,
> we add it now because otherwise we're likely to forget to
> do it later.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target/arm/translate.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index ef64d2559de..2d3a1be518b 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -4229,6 +4229,18 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
>                  if (insn & (1 << 24)) /* pre-decrement */
>                      tcg_gen_addi_i32(addr, addr, -((insn & 0xff) << 2));
>  
> +                if (rn == 13 && w && s->v8m_stackcheck) {

Following previous patches style:

                   if (s->v8m_stackcheck && rn == 13 && w) {

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +                    /*
> +                     * Here 'addr' is the lowest address we will store to,
> +                     * and is either the old SP (if post-increment) or
> +                     * the new SP (if pre-decrement). For post-increment
> +                     * where the old value is below the limit and the new
> +                     * value is above, it is UNKNOWN whether the limit check
> +                     * triggers; we choose to trigger.
> +                     */
> +                    gen_helper_v8m_stackcheck(cpu_env, addr);
> +                }
> +
>                  if (dp)
>                      offset = 8;
>                  else
>