Re: [PATCH] Map registers to remote numbers when encoding an ax_reg or ax_reg_mask operation

Re: [PATCH] Map registers to remote numbers when encoding an ax_reg or ax_reg_mask operation

[Pedro Alves]

On 02/25/2016 01:25 PM, Antoine Tremblay wrote:
> When encoding the agent expression operation ax_reg or ax_reg_mask, the
> register number used is internal to GDB. However GDBServer expects a tdesc
> based number.
> 
> This usually does not cause a problem since at the moment, for raw
> registers GDBServer R trace action ignores the register mask and just
> collects all registers.
> 
> It can be a problem, however with pseudo registers on some platforms if the
> tdesc number doesn't match the GDB internal register number.
> 
> This is the case with ARM, the upcoming ARM tracepoint support, fails
> these test cases without this patch:
> 
> gdb.trace/collection.exp: collect register locals collectively:*
> 
> GDBSever would exit with: unhandled register size
> Since the register number is not mapped.
> 
> This patch fixes these issues by calling gdbarch_remote_register_number
> before encoding the register number in the ax_reg or ax_reg_mask operation.
> 
> Tested on x86 native-gdbserver no regressions observed.

>    else
>      {
> -      int byte = reg / 8;
> +      int byte = 0;

No need to zero initialize.

> +
> +      /* Get the remote register number.  */
> +      reg = gdbarch_remote_register_number (ax->gdbarch, reg);
> +      byte = reg / 8;
>  
>        /* Grow the bit mask if necessary.  */
>        if (byte >= ax->reg_mask_len)
> 

OK with ChangeLog entry.

Thanks,
Pedro Alves

Re: [PATCH] Map registers to remote numbers when encoding an ax_reg or ax_reg_mask operation

[Antoine Tremblay]

Pedro Alves writes:

> On 02/25/2016 01:25 PM, Antoine Tremblay wrote:
>> When encoding the agent expression operation ax_reg or ax_reg_mask, the
>> register number used is internal to GDB. However GDBServer expects a tdesc
>> based number.
>> 
>> This usually does not cause a problem since at the moment, for raw
>> registers GDBServer R trace action ignores the register mask and just
>> collects all registers.
>> 
>> It can be a problem, however with pseudo registers on some platforms if the
>> tdesc number doesn't match the GDB internal register number.
>> 
>> This is the case with ARM, the upcoming ARM tracepoint support, fails
>> these test cases without this patch:
>> 
>> gdb.trace/collection.exp: collect register locals collectively:*
>> 
>> GDBSever would exit with: unhandled register size
>> Since the register number is not mapped.
>> 
>> This patch fixes these issues by calling gdbarch_remote_register_number
>> before encoding the register number in the ax_reg or ax_reg_mask operation.
>> 
>> Tested on x86 native-gdbserver no regressions observed.
>
>>    else
>>      {
>> -      int byte = reg / 8;
>> +      int byte = 0;
>
> No need to zero initialize.

OK.

>
>> +
>> +      /* Get the remote register number.  */
>> +      reg = gdbarch_remote_register_number (ax->gdbarch, reg);
>> +      byte = reg / 8;
>>  
>>        /* Grow the bit mask if necessary.  */
>>        if (byte >= ax->reg_mask_len)
>> 
>
> OK with ChangeLog entry.

Oops, yes I'll add a ChangeLog sorry about that.

Thanks,
Antoine

Re: [PATCH] Map registers to remote numbers when encoding an ax_reg or ax_reg_mask operation

[Antoine Tremblay]

Antoine Tremblay writes:

> Pedro Alves writes:
>
>> On 02/25/2016 01:25 PM, Antoine Tremblay wrote:
>>> When encoding the agent expression operation ax_reg or ax_reg_mask, the
>>> register number used is internal to GDB. However GDBServer expects a tdesc
>>> based number.
>>> 
>>> This usually does not cause a problem since at the moment, for raw
>>> registers GDBServer R trace action ignores the register mask and just
>>> collects all registers.
>>> 
>>> It can be a problem, however with pseudo registers on some platforms if the
>>> tdesc number doesn't match the GDB internal register number.
>>> 
>>> This is the case with ARM, the upcoming ARM tracepoint support, fails
>>> these test cases without this patch:
>>> 
>>> gdb.trace/collection.exp: collect register locals collectively:*
>>> 
>>> GDBSever would exit with: unhandled register size
>>> Since the register number is not mapped.
>>> 
>>> This patch fixes these issues by calling gdbarch_remote_register_number
>>> before encoding the register number in the ax_reg or ax_reg_mask operation.
>>> 
>>> Tested on x86 native-gdbserver no regressions observed.
>>
>>>    else
>>>      {
>>> -      int byte = reg / 8;
>>> +      int byte = 0;
>>
>> No need to zero initialize.
>
> OK.
>
>>
>>> +
>>> +      /* Get the remote register number.  */
>>> +      reg = gdbarch_remote_register_number (ax->gdbarch, reg);
>>> +      byte = reg / 8;
>>>  
>>>        /* Grow the bit mask if necessary.  */
>>>        if (byte >= ax->reg_mask_len)
>>> 
>>
>> OK with ChangeLog entry.
>
> Oops, yes I'll add a ChangeLog sorry about that.
>

Pushed.