Re: [PATCH v19 02/13] linux-user: Add LoongArch signal support

[maobibo]

在 2022/6/24 08:45, maobibo 写道:
> 
> 
> 在 2022/6/24 07:34, Richard Henderson 写道:
>> On 6/23/22 01:55, Song Gao wrote:
>>> +static void setup_sigcontext(CPULoongArchState *env,
>>> +                             struct target_sigcontext *sc,
>>> +                             struct extctx_layout *extctx)
>>> +{
>>> +    int i;
>>> +
>>> +    if (extctx->flags & SC_USED_FP) {
>>> +        __put_user(extctx->fpu.addr, &sc->sc_extcontext[0]);
>>> +    } else {
>>> +        __put_user(extctx->end.addr, &sc->sc_extcontext[0]);
>>> +    }
>>
>> This is incorrect.  Where did this come from?  It certainly doesn't appear 
>> in the kernel's version of setup_sigcontext.  The only reason the result 
>> works for you is that this is overwritten by copy_fpu_to_sigframe within 
>> setup_sigframe.
> 
> The val of flags is SC_USED_FP alway in function setup_extcontext in this 
> version. We want to optimization in future if FP is not used for application 
> where sigcontext for FP is not necessary. Also it can will be extended for 
> 128bit/256bit vector FPU. 

Oh, it is my fault. It is not necessary to set sc_extcontext[0], we will remove 
these sentences, and thank for your guidance.

> 
> regards
> bibo,mao
>>
>>
>> r~
>