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

[Blue Swirl <blauwirbel@gmail.com>]

On Mon, Jul 9, 2012 at 10:27 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> Ping? [patchwork url http://patchwork.ozlabs.org/patch/167132/]

Thanks, applied.

>
> -- PMM
>
> On 25 June 2012 15:55, Peter Maydell <peter.maydell@linaro.org> 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 <peter.maydell@linaro.org>
>> ---
>>  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
>>
>>
>