Subject: Re: [PATCH v2 8/8] powerpc/entry: fix ppc syscall entry issues for common entry

From: Thomas Gleixner <[email-masked]>
Date: Wed, 13 Nov 2024 08:06:04 +0100

On Mon, Nov 11 2024 at 11:19, Luming Yu wrote:
> Due to the common layer and internal calls details are hidden from
> the top level at the call side in ppc arch code, there are some
> difficulties in preserving
> all semantics implications of the original code in the patch. e.g  when
> we got -1 returned
> from syscall_enter_from_user_mode, without touching common code, we have
> to do
> our own inference to recover the reasonable route to return, in order to
> have correct errno
> and syscall work behaviors,that are tested in seccomp_bpf 98 test
> cases.

This indicates that your conversion to the common code is broken to
begin with. Which is not surprising given the amount of issues I found
already.

You need to sit down an come up with a proper conversion design and not
just randomly replace things and then hack around the fallout later on.

If that requires changes to the core code, then they have to be designed
up front and implemented in a way which does not affect existing users.

Thanks,

        tglx