Re: [PATCH] MIPS: Add comment about CONFIG_MIPS32_O32 in loongson3_defconfig when build with Clang

[Jiaxun Yang]

在 2021/3/5 上午7:08, Maciej W. Rozycki 写道:
> On Thu, 4 Mar 2021, Tiezhu Yang wrote:
>
> > This is a known bug [2] with Clang, as Simon Atanasyan said,
> > "There is no plan on support O32 for MIPS64 due to lack of
> > resources".
>
>   Huh?  Is that a joke?  From the o32 psABI's point of view a MIPS64 CPU is
> exactly the same as a MIPS32 one (for whatever ISA revision), so there's
> nothing to support there really other than the CPU/ISA name.

Clang treat MIPS32 as a different backend so we may need some extra 
effort....

TBH it is a toolchain issue and kernel workaround seems bogus.

From my point view we can "s/mips64r2/mips32r2" when doing syscall checks
to workaround clang issue instead of disable it for kernel.

Thanks.

- Jiaxun

>   As much as I dislike all the hacks the Clang community seems to come up
> with for the shortcomings of their tool there has to be a saner workaround
> available rather than forcibly disabling support for the o32 ABI with
> CONFIG_64BIT kernels, but the report is missing the compiler invocation
> line triggering the issue (V=1 perhaps?), which should be included with
> any commit description anyway, so I can't suggest anything based on the
> limited information provided.
>
>    Maciej