Re: [Qemu-devel] [PATCH 3/3] capstone: Enable disassembly for s390x

[David Hildenbrand]

On 23.05.19 04:42, Richard Henderson wrote:
> Enable s390x, aka SYSZ, in the git submodule build.
> Set the capstone parameters for both s390x host and guest.
> Install a skipdata hook to keep capstone in sync with the
> instruction stream for unknown opcodes.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  Makefile           |  1 +
>  disas.c            | 40 ++++++++++++++++++++++++++++++++++++++++
>  target/s390x/cpu.c |  4 ++++
>  3 files changed, 45 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index 155f066a20..a37e872825 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -477,6 +477,7 @@ CAP_CFLAGS += -DCAPSTONE_USE_SYS_DYN_MEM
>  CAP_CFLAGS += -DCAPSTONE_HAS_ARM
>  CAP_CFLAGS += -DCAPSTONE_HAS_ARM64
>  CAP_CFLAGS += -DCAPSTONE_HAS_POWERPC
> +CAP_CFLAGS += -DCAPSTONE_HAS_SYSZ
>  CAP_CFLAGS += -DCAPSTONE_HAS_X86
>  
>  subdir-capstone: .git-submodule-status
> diff --git a/disas.c b/disas.c
> index 41ad0102e2..c1ecd2d769 100644
> --- a/disas.c
> +++ b/disas.c
> @@ -179,6 +179,39 @@ static int print_insn_od_target(bfd_vma pc, 
> disassemble_info *info)
>     to share this across calls and across host vs target disassembly.  */
>  static __thread cs_insn *cap_insn;
>  
> +/*
> + * The capstone library always skips 2 bytes for S390X.
> + * This is less than ideal, since we can tell from the first two bits
> + * the size of the insn and thus stay in sync with the insn stream.
> + */
> +static size_t CAPSTONE_API
> +cap_skipdata_s390x_cb(const uint8_t *code, size_t code_size,
> +                      size_t offset, void *user_data)
> +{
> +    size_t ilen;
> +
> +    /* See get_ilen() in target/s390x/internal.h.  */
> +    switch (code[offset] >> 6) {
> +    case 0:
> +        ilen = 2;
> +        break;
> +    case 1:
> +    case 2:
> +        ilen = 4;
> +        break;
> +    default:
> +        ilen = 6;
> +        break;
> +    }
> +
> +    return ilen;

return (code[offset] >> 6) << 1; ?



-- 

Thanks,

David / dhildenb