Re: [Qemu-devel] [PATCH v7 03/11] target/arm: Move BE32 disassembler fixup

[Philippe Mathieu-Daudé]

On 10/21/2017 09:46 PM, Richard Henderson wrote:
> The Capstone disassembler has its own big-endian fixup.
> Doing this twice does not work, of course.  Move our current
> fixup from target/arm/cpu.c to disas/arm.c.
> 
> This makes read_memory_inner_func unused and can be removed.
> 
> Signed-off-by: Richard Henderson <address@hidden>

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

> ---
>  include/disas/bfd.h |  7 -------
>  disas/arm.c         | 21 ++++++++++++++++-----
>  target/arm/cpu.c    | 19 -------------------
>  3 files changed, 16 insertions(+), 31 deletions(-)
> 
> diff --git a/include/disas/bfd.h b/include/disas/bfd.h
> index d99da68267..2852f80ed6 100644
> --- a/include/disas/bfd.h
> +++ b/include/disas/bfd.h
> @@ -307,12 +307,6 @@ typedef struct disassemble_info {
>      (bfd_vma memaddr, bfd_byte *myaddr, int length,
>            struct disassemble_info *info);
>  
> -  /* A place to stash the real read_memory_func if read_memory_func wants to
> -     do some funky address arithmetic or similar (e.g. for ARM BE32 mode).  
> */
> -  int (*read_memory_inner_func)
> -    (bfd_vma memaddr, bfd_byte *myaddr, int length,
> -             struct disassemble_info *info);
> -
>    /* Function which should be called if we get an error that we can't
>       recover from.  STATUS is the errno value from read_memory_func and
>       MEMADDR is the address that we were trying to read.  INFO is a
> @@ -479,7 +473,6 @@ int generic_symbol_at_address(bfd_vma, struct 
> disassemble_info *);
>    (INFO).buffer_vma = 0, \
>    (INFO).buffer_length = 0, \
>    (INFO).read_memory_func = buffer_read_memory, \
> -  (INFO).read_memory_inner_func = NULL, \
>    (INFO).memory_error_func = perror_memory, \
>    (INFO).print_address_func = generic_print_address, \
>    (INFO).print_insn = NULL, \
> diff --git a/disas/arm.c b/disas/arm.c
> index 27396dd3e1..9967c45990 100644
> --- a/disas/arm.c
> +++ b/disas/arm.c
> @@ -70,6 +70,17 @@ static void floatformat_to_double (unsigned char *data, 
> double *dest)
>      *dest = u.f;
>  }
>  
> +static int arm_read_memory(bfd_vma memaddr, bfd_byte *b, int length,
> +                           struct disassemble_info *info)
> +{
> +    assert((info->flags & INSN_ARM_BE32) == 0 || length == 2 || length == 4);
> +
> +    if ((info->flags & INSN_ARM_BE32) != 0 && length == 2) {
> +        memaddr ^= 2;
> +    }
> +    return info->read_memory_func(memaddr, b, length, info);
> +}
> +
>  /* End of qemu specific additions.  */
>  
>  struct opcode32
> @@ -3810,7 +3821,7 @@ find_ifthen_state (bfd_vma pc, struct disassemble_info 
> *info,
>         return;
>       }
>        addr -= 2;
> -      status = info->read_memory_func (addr, (bfd_byte *)b, 2, info);
> +      status = arm_read_memory (addr, (bfd_byte *)b, 2, info);
>        if (status)
>       return;
>  
> @@ -3882,7 +3893,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info 
> *info)
>        info->bytes_per_chunk = size;
>        printer = print_insn_data;
>  
> -      status = info->read_memory_func (pc, (bfd_byte *)b, size, info);
> +      status = arm_read_memory (pc, (bfd_byte *)b, size, info);
>        given = 0;
>        if (little)
>       for (i = size - 1; i >= 0; i--)
> @@ -3899,7 +3910,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info 
> *info)
>        info->bytes_per_chunk = 4;
>        size = 4;
>  
> -      status = info->read_memory_func (pc, (bfd_byte *)b, 4, info);
> +      status = arm_read_memory (pc, (bfd_byte *)b, 4, info);
>        if (little)
>       given = (b[0]) | (b[1] << 8) | (b[2] << 16) | ((unsigned)b[3] << 24);
>        else
> @@ -3915,7 +3926,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info 
> *info)
>        info->bytes_per_chunk = 2;
>        size = 2;
>  
> -      status = info->read_memory_func (pc, (bfd_byte *)b, 2, info);
> +      status = arm_read_memory (pc, (bfd_byte *)b, 2, info);
>        if (little)
>       given = (b[0]) | (b[1] << 8);
>        else
> @@ -3929,7 +3940,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info 
> *info)
>             || (given & 0xF800) == 0xF000
>             || (given & 0xF800) == 0xE800)
>           {
> -           status = info->read_memory_func (pc + 2, (bfd_byte *)b, 2, info);
> +           status = arm_read_memory (pc + 2, (bfd_byte *)b, 2, info);
>             if (little)
>               given = (b[0]) | (b[1] << 8) | (given << 16);
>             else
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 88578f360e..82dad0b721 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -473,21 +473,6 @@ print_insn_thumb1(bfd_vma pc, disassemble_info *info)
>    return print_insn_arm(pc | 1, info);
>  }
>  
> -static int arm_read_memory_func(bfd_vma memaddr, bfd_byte *b,
> -                                int length, struct disassemble_info *info)
> -{
> -    assert(info->read_memory_inner_func);
> -    assert((info->flags & INSN_ARM_BE32) == 0 || length == 2 || length == 4);
> -
> -    if ((info->flags & INSN_ARM_BE32) != 0 && length == 2) {
> -        assert(info->endian == BFD_ENDIAN_LITTLE);
> -        return info->read_memory_inner_func(memaddr ^ 2, (bfd_byte *)b, 2,
> -                                            info);
> -    } else {
> -        return info->read_memory_inner_func(memaddr, b, length, info);
> -    }
> -}
> -
>  static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
>  {
>      ARMCPU *ac = ARM_CPU(cpu);
> @@ -513,10 +498,6 @@ static void arm_disas_set_info(CPUState *cpu, 
> disassemble_info *info)
>          info->endian = BFD_ENDIAN_BIG;
>  #endif
>      }
> -    if (info->read_memory_inner_func == NULL) {
> -        info->read_memory_inner_func = info->read_memory_func;
> -        info->read_memory_func = arm_read_memory_func;
> -    }
>      info->flags &= ~INSN_ARM_BE32;
>      if (arm_sctlr_b(env)) {
>          info->flags |= INSN_ARM_BE32;

--enable-capstone and --disable-capstone:

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