Re: [Qemu-devel] [PATCH 11/13] target/arm: Add v8M stack checks for Thumb push/pop

[Philippe Mathieu-Daudé]

On 02/10/2018 18:35, Peter Maydell wrote:
> Add v8M stack checks for the 16-bit Thumb push/pop
> encodings: STMDB, STMFD, LDM, LDMIA, LDMFD.
> 
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  target/arm/translate.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 65df8d6975c..ef64d2559de 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -12251,7 +12251,10 @@ static void disas_thumb_insn(DisasContext *s, 
> uint32_t insn)
>              store_reg(s, rd, tmp);
>              break;
>          case 4: case 5: case 0xc: case 0xd:
> -            /* push/pop */
> +            /*
> +             * 0b1011_x10x_xxxx_xxxx
> +             *  - push/pop
> +             */
>              addr = load_reg(s, 13);
>              if (insn & (1 << 8))
>                  offset = 4;
> @@ -12264,6 +12267,17 @@ static void disas_thumb_insn(DisasContext *s, 
> uint32_t insn)
>              if ((insn & (1 << 11)) == 0) {
>                  tcg_gen_addi_i32(addr, addr, -offset);
>              }
> +
> +            if (s->v8m_stackcheck) {
> +                /*
> +                 * Here 'addr' is the lower of "old SP" and "new SP";
> +                 * if this is a pop that starts below the limit and ends
> +                 * above it, it is UNKNOWN whether the limit check triggers;
> +                 * we choose to trigger.
> +                 */
> +                gen_helper_v8m_stackcheck(cpu_env, addr);
> +            }
> +
>              for (i = 0; i < 8; i++) {
>                  if (insn & (1 << i)) {
>                      if (insn & (1 << 11)) {
>