Re: [Qemu-devel] [PATCH] disas: Fix printing of addresses in disassembly

[Peter Maydell]

Ping? [patchwork url http://patchwork.ozlabs.org/patch/167132/]

-- PMM

On 25 June 2012 15:55, Peter Maydell <address@hidden> wrote:
> In our disassembly code, the bfd_vma type is always 64 bits,
> even if the target's virtual address width is only 32 bits. This
> means that when we print out addresses we need to truncate them
> to 32 bits, to avoid odd output which has incorrectly sign-extended
> a value to 64 bits, for instance this ARM example:
>     0x80479a60:  e59f4088     ldr  r4, [pc, #136]  ; 0xffffffff80479a4f
>
> (It would also be possible to truncate before passing the address
> to info->print_address_func(), but truncating in the final print
> function is the same approach that binutils takes to this problem.)
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  disas.c |   19 +++++++++++++++++++
>  1 files changed, 19 insertions(+), 0 deletions(-)
>
> diff --git a/disas.c b/disas.c
> index 93d8d30..7b2acc9 100644
> --- a/disas.c
> +++ b/disas.c
> @@ -64,6 +64,22 @@ generic_print_address (bfd_vma addr, struct 
> disassemble_info *info)
>      (*info->fprintf_func) (info->stream, "0x%" PRIx64, addr);
>  }
>
> +/* Print address in hex, truncated to the width of a target virtual address. 
> */
> +static void
> +generic_print_target_address(bfd_vma addr, struct disassemble_info *info)
> +{
> +    uint64_t mask = ~0ULL >> (64 - TARGET_VIRT_ADDR_SPACE_BITS);
> +    generic_print_address(addr & mask, info);
> +}
> +
> +/* Print address in hex, truncated to the width of a host virtual address. */
> +static void
> +generic_print_host_address(bfd_vma addr, struct disassemble_info *info)
> +{
> +    uint64_t mask = ~0ULL >> (64 - (sizeof(void *) * 8));
> +    generic_print_address(addr & mask, info);
> +}
> +
>  /* Just return the given address.  */
>
>  int
> @@ -154,6 +170,7 @@ void target_disas(FILE *out, target_ulong code, 
> target_ulong size, int flags)
>      disasm_info.read_memory_func = target_read_memory;
>      disasm_info.buffer_vma = code;
>      disasm_info.buffer_length = size;
> +    disasm_info.print_address_func = generic_print_target_address;
>
>  #ifdef TARGET_WORDS_BIGENDIAN
>      disasm_info.endian = BFD_ENDIAN_BIG;
> @@ -274,6 +291,7 @@ void disas(FILE *out, void *code, unsigned long size)
>      int (*print_insn)(bfd_vma pc, disassemble_info *info);
>
>      INIT_DISASSEMBLE_INFO(disasm_info, out, fprintf);
> +    disasm_info.print_address_func = generic_print_host_address;
>
>      disasm_info.buffer = code;
>      disasm_info.buffer_vma = (uintptr_t)code;
> @@ -386,6 +404,7 @@ void monitor_disas(Monitor *mon, CPUArchState *env,
>      monitor_disas_env = env;
>      monitor_disas_is_physical = is_physical;
>      disasm_info.read_memory_func = monitor_read_memory;
> +    disasm_info.print_address_func = generic_print_target_address;
>
>      disasm_info.buffer_vma = pc;
>
> --
> 1.7.1
>
>