Re: nios2: is the ptrace ABI correct?

[Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>]

On 03/11/2015 04:48 AM, Ley Foon Tan wrote:
> On Tue, Mar 10, 2015 at 2:17 PM, Chung-Lin Tang <cltang@codesourcery.com> wrote:
>> On 2015/3/10 10:54 AM, Ley Foon Tan wrote:
>>> On Tue, Mar 10, 2015 at 1:05 AM, Ezequiel Garcia
>>> <ezequiel@vanguardiasur.com.ar> wrote:
>>>>
>>>>
>>>> On 03/09/2015 02:02 PM, Chung-Lin Tang wrote:
>>>>> On 2015/3/10 12:54 AM, Chung-Lin Tang wrote:
>>>>>> It appears that some of the ways nios2 has organized the
>>>>>> ucontext/pt_regs/etc. are remnants of the pre-generic code, some
>>>>>> basically because the port was based off m68k.
>>>>>>
>>>>>> I've re-organized the headers a bit: nios2/include/asm/ucontext.h is
>>>>>> deleted, and re-definition of struct sigcontext now allows use of
>>>>>> uapi/asm-generic/ucontext.h directly.  Note that the reorg, despite
>>>>>> effectively renaming some fields, is still binary compatible. I'll
>>>>>> probably update the corresponding glibc definitions later.
>>>>>>
>>>>>> struct pt_regs is now not exported, and all exported register sets are
>>>>>> now supposed to follow the 49 register set defined as in GDB now.
>>>>>>
>>>>>> Tobias, Ley Foon, how do you think this looks?
>>>>>
>>>>> Sorry, accidentally attached unrelated GCC patch instead, this one's the
>>>>> correct one.
>>>>>
>>>>
>>>> Looks good. I'm wondering if...
>>>>
>>>> +/* User structures for general purpose registers.  */
>>>> +struct user_pt_regs {
>>>> +       __u32           regs[49];
>>>>  };
>>>>
>>>> Can we expose the registers explicitly here? Like this:
>>>>
>>>> struct user_pt_regs {
>>>>         __u32 r0;
>>>>         __u32 r1;
>>>>         ...
>>>>         __u32 sp;
>>>>         __u32 gp;
>>>>         __u32 estatus;
>>>> };
>>>>
>>>> It looks self-documenting and thus easier to use.
>>>
>>> Hi Chung-Lin,
>>>
>>> Your patch look good to me.
>>> Do you have any problem to change the struct user_pt_regs based on
>>> Ezequiel's suggestion?
>>
>> Well, exposing the register names like that sort of defeats the purpose of
>> the PTR_* defines.
>>
>> Judging from the overall trend of style in arch/*/include/uapi/asm/ptrace.h
>> across ports, I would prefer to stay with the array field.
>>
> Okay, I will include your patch.
> 

That'd be great.

I'll wait until Linus takes the change, and then will submit the strace
support to strace mailing list.

Thanks for the help!
-- 
Ezequiel Garcia, VanguardiaSur
www.vanguardiasur.com.ar