Re: [PATCH] LoongArch: Modify some member names in mcontext_t and ucontext_t structs to align them with the kernel.

[caiyinyu <caiyinyu@loongson.cn>]

在 2023/3/24 下午3:40, Xi Ruoyao 写道:
> On Fri, 2023-03-24 at 14:25 +0800, caiyinyu wrote:
>>   typedef struct mcontext_t
>>   {
>> -  unsigned long long __pc;
>> -  unsigned long long __gregs[32];
>> -  unsigned int __flags;
>> -  unsigned long long __extcontext[0] __attribute__((__aligned__(16)));
>> +  unsigned long long __ctx(sc_pc);
>> +  unsigned long long __ctx(sc_regs)[32];
>> +  unsigned int __ctx(sc_flags);
>> +  unsigned long long __ctx(sc_extcontext)[0] __attribute__((__aligned__(16)));
>>   } mcontext_t;
> How about this?
>
> __extension__ typedef struct mcontext_t
> {
>    union
>      {
>        /* Backward compatibility names.  */
>        struct
>        {
> 	unsigned long long __pc;
> 	unsigned long long __gregs[32];
> 	unsigned int __flags;
> 	unsigned long long __extcontext[0] __attribute__((__aligned__(16)));
>        };
>        struct
>        {
> 	unsigned long long __ctx(sc_pc);
> 	unsigned long long __ctx(sc_regs)[32];
> 	unsigned int __ctx(sc_flags);
> 	unsigned long long __ctx(sc_extcontext)[0] __attribute__((__aligned__(16)));
>        };
>      };
> } mcontext_t;

Your plan caused fails in glibc conform tests.

We wanted to inform you that we are aware that the proposed 
modification[1] will affect the public API. However, since LoongArch 
Musl has not yet been released, and the LoongArch Euler system, Debian 
system, Alpine, and other systems are still in early development stages, 
we have not yet widely released the system. Therefore, we believe it is 
necessary to proceed with the modification.

We do not want to carry the burden of history and remain committed to 
proceeding with the modification. Additionally, we also plan to backport 
this patch[1] to versions 2.36 and 2.37 to address the issue of 
inconsistent naming of musl/glibc/kernel sigcontext/mcontext_t members 
from the source, resolving this issue at the root. This will eliminate 
potential problems for future software and system development.

[1] patch:

https://sourceware.org/pipermail/libc-alpha/2023-March/146607.html